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As KNA/RNAS Chair I wish to open the conference, during a 10min presentation in which I also shall recall the WWII episode of the Society. After the 10min I will hand over to the LOC Chair.
HARPS3 is a high resolution (R~115,000) stabilized Doppler spectrograph covering a wavelength range from 380-690nm with polarimetric capabilities that is coming online on the roboticized 2.5m Isaac Newton Telescope (INT) at La Palma in Fall 2025. HARPS3 is designed to enable ~10cm/s radial velocity (RV) precision on nearby bright solar-type stars to enable the detection of Earth Twins. The Netherlands is a major partner in the instrument having contributed key hardware as well as being a partner of the INT. A component of the time on the telescope (~50%) will be used to carry out the Terra Hunting Experiment (THE), a 10-year survey to probe for Earth-twins around nearby bright solar-type stars. Additionally, about ~1h of Open Time will be available for the Dutch Community per night. In this talk, we will discuss HARPS3, its capabilities, and results from a Community Discussion Day held in March 2025 to discuss possible science cases for the Dutch Open Time.
I will present the status of WEAVE, the new wide-field spectroscopic survey facility for the William Herschel Telescope at the ING, and some early science results. WEAVE has been operational in its Large Integral-Field Unit (LIFU) mode since late 2022 and is presently commissioning its MultiObject Spectroscopy (MOS) and mini-IFU (mIFU) modes. I will present the instrument performance in the modes and some early science results, concentrating on interacting galaxies, planetary nebulae, and supernovae physics, just a small cross-section of the possible science cases of this powerful new instrument. I will conclude with a brief advertisement of how to access WEAVE through the ING Open Time and how to become involved in the WEAVE Survey.
One of the remaining unsolved questions is the one of globular cluster formation, as there is still no definite consensus on whether the clusters have formed within the Milky Way galaxy (in situ) or have been accreted. Current estimates suggest that between 25-65% of all Milky Way GCs were accreted, however the exact number is still uncertain. Since GCs are significantly old (up to 12 Gyr), determining their place of origin will provide information about the early stages of Milky Way history.
In our study we aimed to determine their origin by deriving their chemical abundances from the integrated light spectra. We observed 8 hardly studied GCs with the recently deployed WEAVE Large Integral Field Unit with spectral resolution of R ~ 10 000. WEAVE is a multi-object fiber spectrograph installed on the William Herschel Telescope, and it can simultaneously obtain up to a thousand spectra. Our sample covers a range of metallicities, locations in the Milky Way and presence of tidal features. From the integrated light spectra we determined the abundances of [Fe/H] and alpha-elements, and compared them to the abundances of the individual stars.
In June 2023, International Pulsar Timing Array (IPTA) collaborations in Europe, America, India and Australia simultaneously announced the first compelling evidence of the low-frequency (nHz) gravitational wave background. This was a milestone in gravitational wave astronomy. These results were further strengthened by detailed comparative analysis at the IPTA level. The main source of noise in the PTA data set is the time variations of the Dispersion Measure (DM) caused by the propagation of the pulsar signal through the turbulent intervening interstellar medium and the solar wind. The European interferometers LOFAR and NenuFAR, operating below ~240 and ~100 MHz respectively, provide the most sensitive constraints of DM variations. In this talk, I will present state-of-the-art results from the IPTA and showcase the importance of LOFAR and NenuFAR in improving precision and boosting sensitivity to the gravitational wave background. I will place these results in the context of the upcoming third data release of the International Pulsar Timing Array, which will provide the most sensitive detection of the gravitational wave background to date.
Expect all poster presenters to be there so the poster price committee can ask questions
Expect all poster presenters to be there so the poster price committee can ask questions
Astrophysical research is increasingly leveraging data science, statistics and machine learning, with applications ranging from detecting transients in images to inferring exoplanet atmospheres. However, studying the most energetic phenomena in the universe presents particular challenges, including comparatively small, heterogeneous datasets and a lack of reliable training data. This talk provides a brief overview of the work my group is doing in statistics and machine learning for astronomy. I will highlight recent opportunities and challenges in integrating machine learning into astrophysical data analysis, as well as connections to other areas of astronomy. I will show recent results and ongoing work exploring how machine learning can uncover the origin of the most extreme astrophysical phenomena, such as accreting black holes, neutron stars, and the mysterious sources known as Fast Radio Bursts.
Fast radio bursts (FRBs) are one of the most exciting mysteries in contemporary astrophysics. They last only a fraction of a second but are bright enough to be detectable from halfway across the Universe. FRBs are unique astrophysical tools: they are perfect point sources, impulsive, and being in the radio band they are also distorted in ways that carry valuable information about otherwise invisible matter, which makes them unprecedented probes of the local environments of compact objects and the structure and magnetization of the interstellar and intergalactic media. FRBs will be even more useful when we better understand their sources and emission. A small fraction of FRBs has been observed to repeat, which has ruled out a cataclysmic origin for these sources and allows for detailed multi-wavelength follow-up observations that constrain FRB models. It is as-yet unclear whether all FRBs repeat and if FRB models based on a few well-studied repeaters can be extrapolated to the full population. Canada's CHIME telescope has been instrumental in uncovering the diversity of FRBs: it provided the first large statistical sample of FRBs, and it is continuing to lead the discovery of repeating sources by revisiting the Northern sky every day. At the same time, we have opened a new window into studying these sources by detecting the lowest-frequency FRBs with the LOFAR telescope. I will argue that the next revolution in FRB science is imminent through the collection of the first large sample of FRBs with known redshifts through the CHIME/FRB "Outriggers" upgrade. Complemented by observations from LOFAR 2.0 and other facilities, this promises to solve the mystery of FRBs and will uniquely address a variety of unsolved problems in astrophysics, such as the detection of the "missing" baryons and the impact of feedback on the formation of galaxy haloes.
Massive stars are chemical factories, they are progenitors of supernovae, neutron stars and black holes, and they play a crucial role in the formation and evolution of their local environment as well as their entire host galaxies. Given their prevalence in close binary systems, at the end of their lives they may produce double-compact objects, which are potential gravitational-wave sources. During their life cycles, interactions with their companion stars drastically alter the evolution of both stars. Yet, the complex interaction physics as well as the outcome of the interactions remain poorly understood.
To address these open questions, especially at low metallicity, where most of the gravitational-wave sources originate, we recently initiated the large-scale spectroscopy survey "BLOeM: Binarity at Low Metallicity", which collects multi-epoch spectroscopy of a sample of ~1000 massive stars in our neighboring Galaxy, the Small Magellanic Cloud (SMC).
In my talk, I will present new BLOeM results about the multiplicity properties of massive stars in the SMC. I will discuss the observed binary fractions across the upper Hertzsprung-Russell diagram, from O- and B-type dwarfs towards B- and late-type supergiants, and provide the spectroscopic binary properties of a large sample of rapidly rotating OeBe stars for the first time. I will discuss trends in the binary fractions as a function of evolutionary status and masses of the stars, and compare our findings to state-of-the-art binary predictions. This will provide crucial new insights in the binary-interaction physics that are at play.
Gravitational waves (GW) are providing a new way to study the properties of compact objects. In this context, understanding what determines the final fate of stars, the role of binary interactions, and which signatures to expect in GW observations is becoming increasingly important. The formation of black holes (BHs) or neutron stars (NS) is not a simple function of the initial mass of a massive star. Instead, it depends on the hearts of stars, i.e. their core structures at the onset of core collapse. Using detailed stellar models, we investigate the origin of variations in final core structure as a function of mass and show that these are determined by stellar physics, i.e., the timing and energetics of the latest burning phases. We demonstrate how binary mass transfer modifies the core structure of stars and thus their fate. Our results imply that binary-stripped stars produce universal BH masses across metallicity. We predict that these lead to features in the chirp-mass distribution of binary BH mergers that can explain the observed gap at 10-12 solar masses and peaks at 8 and 12 solar masses found in GW observations. We discuss the implications of these findings for constraining uncertain stellar and supernova physics.
Expect all poster presenters to be there so the poster price committee can ask questions
How the chemistry in the universe evolves from diffuse interstellar medium to a life-harboring environment on our Earth? Complex organic molecules (COMs), typically defined as carbon-bearing molecules with at least six atoms, have gained their popularity over the past several decades due to their importance of linking atoms and simple molecules with prebiotic species. COMs are suggested to be first formed in ice mantles of dust grains during the cold pre-stellar phase, and then sublimated into the gas phase when temperature goes up in the hot core phase. Gas-phase COMs can be observed in (sub)millimeter wavelengths using radio telescopes like ALMA, which is the most powerful one and has detected a rich inventory of COMs in star-forming regions, mostly in Class 0 protostars. The detection of solid-phase COMs (i.e., COM ices) was only confirmed for methanol (CH3OH), the simplest COM, but is now becoming promising for other COMs using JWST and its Mid-InfraRed Instrument (MIRI). The absorption bands of COM ices mainly fall in the mid-infrared, especially the fingerprint region between 6.8 and 8.8 µm that contains a series of vibrational modes of oxgen-bearing COMs (O-COMs). Tracing COMs in both phases in young stellar objects (YSOs) can help us probe their formation history, and shed light on how the chemistry evolves from simple to complex in the universe. We will show the results from the latest ALMA and JWST observations with a nonexclusive focus on O-COMs, which are relatively abundant and therefore more detectable for both telescopes. We start with case studies on two low-mass protostars that are famous for their rich COM chemistry in both gas and ice, NGC 1333 IRAS 2A and B1-c, as part of our JWST Observations of Young protoStars (JOYS+) program. By comparing the ratios between O-COMs and the reference species such as H2O and CH3OH, we find that COMs are likely to be inherited from ice to gas, while there is also evidence of gas-phase reprocessing that alters the COM ratios in the two phases. A more statistical study on a larger JOYS+ sample is undergoing.
In the past decade, hundreds of exoplanets have been discovered in extremely short orbits below 10 days. Unlike in the Solar System, planets in these systems orbit their host stars close enough to disturb the stellar magnetic field lines. The interaction can enhance the star's magnetic activity, such as its chromospheric and radio emission, or flaring. So far, the search for magnetic star-planet interactions has remained inconclusive. In this talk, I present the first detection of planet-induced flares on HIP 67522, a 17 million-year-old G dwarf star with two known close-in planets. Combining space-borne photometry from TESS and dedicated CHEOPS observations over a span of 5 years, we find that the 15 flares in HIP 67522 cluster near the innermost planet's transit phase, indicating persistent magnetic star-planet interaction in the system. The stability of interaction implies that the innermost planet is continuously self-inflicting a six times higher flare rate than it would experience without interaction. The subsequent flux of energetic radiation and particles bombarding HIP 67522 b may explain the planet's remarkably extended atmosphere, recently detected with the James Webb Space Telescope, potentially doubling its mass loss rate. Our results establish HIP 67522 as the archetype system for flaring star-planet interaction, and urge further characterization of the dynamic magnetism of this and similar star-planet systems.
Accretion and outflows are astrophysical phenomena observed across a wide range of objects, from white dwarfs to supermassive black holes. Developing a complete picture of these processes requires complementary studies across this full spectrum of jet-launching sources. In particular, jet–interstellar medium interaction sites near black hole X-ray binaries provide an indirect probe of the energetics of the jets launched from stellar-mass black holes and their long-term impact on their surroundings.
In this talk, I will present the discovery of bow shock structures near two unique black hole X-ray binaries, Cyg X-1 and GRS 1915+105. We used MeerKAT, a radio telescope based in South Africa, to investigate the surroundings of these active black hole X-ray binaries. We discovered a bow shock structure near GRS 1915+105, which was long theorized but never detected before. Additionally, we conducted a deep study of the Cyg X-1 bow shock in multiple frequencies, providing the first spectral index map of the bow shock.
The dark jets that create these structures, though undetectable in the electromagnetic spectrum at large distances, encode their life-long activity and energetics in these structures. Beyond showcasing MeerKAT’s ability to detect faint, extended emission, these systems serve as benchmarks for future searches, shaping our understanding of jet feedback from stellar-mass black holes in the Galaxy.
The Event Horizon Telescope (EHT) has imaged the black hole shadows of the supermassive black hole at the center of the galaxy M87 (M87) and at the center of the Milky Way (Sgr A), using the technique of very long baseline interferometry (VLBI) at 230 GHz. In the future, black hole imaging will transition to movie making with ground-based upgrades and extensions of the EHT array. However, due to the limited size of the Earth and severe atmospheric absorption and turbulence at frequencies higher than ~345 GHz, obtaining image resolutions higher than ~15 micro-arcseconds from Earth is not feasible. Using submm telescopes in space, razor-sharp and high-fidelity images and movies of black holes can be made. We will present the Event Horizon Imager (EHI) concept. The EHI consists of two or three satellites operating as a fully space-based VLBI array in Medium Earth Orbits at frequencies up to 690 or even 900 GHz, attaining a resolution of ~2 micro-arcseconds with a fully filled uv-plane. Correlation is envisioned to be performed on-board so that the downlink data rate is limited, while a hybrid concept downlinking raw data during space-ground campaigns is also considered. EHI images will provide precision measurements of the thin black hole photon ring, leading to spin constraints and precision tests of general relativity in an unexplored regime. High-resolution polarimetric images of jets will test theories of jet launching and spin energy extraction from black holes. Shadows can be imaged for a population of black holes. We will also present the EHI Pathfinder (EHIP), which will demonstrate the space-to-space VLBI technique in orbit and provide images of AGN jets at cm wavelengths with unprecedented resolution and fidelity.
While the political attention to it is waning, the scientific facts have not changed. Human-induced climate change is already causing damage and misery, and unless the world acts quickly and decisively, this will increase in the decades to come. The scientific information on climate change is assessed and brought to climate policymakers globally by a special organization: the IPCC. In this talk, Heleen de Coninck, professor at Eindhoven University of Technology and Radboud University, vice-chair of the Netherlands Scientific Climate Council, and author of several IPCC reports, will explain how IPCC works and makes it so unique, and what the scientific and political state of play is on climate change. She will discuss the difference between 1.5 and 2C of warming, what is needed to limit warming to levels consistent with the Paris Agreement, and the current state of Dutch climate policy.
Active galactic nuclei (AGNs) play a crucial role in the coevolution of supermassive black holes (SMBHs) and their host galaxies from high redshift to the present. They influence their host galaxies through powerful winds and jets that generate massive outflows, and these feedback processes can either quench star formation by heating and expelling gas or trigger it by compressing the interstellar medium. The molecular phase, being the most substantial component of these outflows, can be traced through emissions from the $^{12}$CO line. In this talk, by leveraging data of CO(2-1), CO(3-2), and CO(6-5) transitions at $\sim0.1''$ ($\sim7\,\rm pc$) resolution from the Atacama Large Millimeter Array (ALMA), I will present temperature, density, and kinematics analyses within the circumnuclear disk (CND) of NGC 1068, focusing on molecular outflows. We find regions close to or within the AGN wind bicone exhibit a multicomponent molecular outflow with significant velocity departures from the galaxy's mean motion. We also observed lateral variations of the CO gas kinematics along the edge and center of the AGN wind bicone, as well as a misalignment of the orientation and spread between the molecular outflow and the ionized outflow. Overall, due to the optically thin condition of the outflowing CO gas, the dynamic impact of the ionized outflow to the molecular gas inside the CND might not be as substantial as expected, reflected by the small molecular mass outflow rate in most parts of the CND ($\lesssim\,5.5\,\rm M_{\odot}\,\rm yr^{-1}$). Regardless, the outflowing molecular gas across the CND exhibits complex kinematics, highlighted by an asymmetry between the northeastern and southern CND, consistent with the morphology of the large-scale radio jet. Future ALMA observations, particularly those with enhanced spatial resolution, could offer a more detailed understanding of the molecular gas kinematics near the AGN torus and its interaction with the surrounding interstellar medium (ISM). By mapping outflows from small-scale structures, such as the torus, to their large-scale interactions with the ISM, we can further elucidate the mechanisms linking AGN activity to the global properties of their host galaxies.
Dwarf galaxies play an important role when studying the effects of the environment on galaxy formation and evolution. The Fornax cluster, having a dense core and strong tidal fields, offers an ideal laboratory for investigating the influence of the cluster environment on the morphology of dwarf galaxies. We explore the relationship between the morphology of galaxies, in particular the asymmetries, and their distances to the cluster centre to study the effect of tidal forces and other environmental processes. We did this by investigating the detailed morphologies of a complete magnitude-limited sample of 556 galaxies within the Fornax cluster, spanning a radius range up to 1.75 Mpc from its central to the outer regions. For galaxies in the Fornax Deep Survey, we quantified the morphologies of dwarf galaxies using the non-parametric quantities asymmetry (A) and smoothness (S), as part of the CAS system. Unlike previous work, we used isophotal CAS parameters, which are sensitive to the outer parts of galaxies. We constructed A ‑ r (asymmetry vs. distance to cluster centre) and S ‑ r (smoothness vs. distance to the cluster centre) diagrams to investigate the relationship between morphology and distance. Additionally, we examined the effects of asymmetry on magnitude and colour. Furthermore, to better understand the assembly history of the galaxy cluster, we performed a phase-space analysis for Fornax dwarf galaxies, using spectroscopic redshifts and the projected distance from the cluster centre. We find that dwarf galaxies in the outer regions of the Fornax cluster have higher values of asymmetry compared to other dwarfs in the cluster, indicating a greater degree of morphological disturbances within dwarf galaxies in these regions. We also find that galaxies in the very inner regions are more asymmetric than those farther out. The A-magnitude relation reveals a trend where asymmetry increases as galaxies become fainter, and the A-colour relation shows that galaxies with bluer colours tend to exhibit stronger asymmetry. We do not find any correlations with smoothness, except that smoothness strongly decreases with stellar mass. We propose that the higher asymmetry of dwarfs in the outer regions is most likely caused by ram pressure stripping. As galaxies fall into the cluster, gas is expelled by intracluster winds, causing 'jellyfish-like' tails and leading to star formation not only in the central regions but also along the tails; this causes the asymmetric features. These asymmetries persist until the galaxies evolve into completely quiescent and elliptical systems. The observed dwarfs likely represent a transitional phase, during which they are nearing quiescence but still retain residual asymmetry from earlier interactions. In the very inner parts, the asymmetries most likely are caused by tidal effects. In addition, our phase-space diagram suggests that galaxies near pericentre in the Fornax cluster exhibit significantly higher asymmetry, indicating that morphological disturbances occurred during their first pericentric passage.
It remains an unanswered question what dictates the amount of dust in the interstellar medium. Asymptotic giant branch stars and supernovae produce dust in their cold atmospheres, but dust gets destroyed during star-formation and supernova shockwaves. The timescales for these effects combined with the observed dust masses in galaxies implies that dust also grows in the interstellar medium.
This implies that amount of dust in a galaxy is directly linked to the star formation history and how efficient dust can accrete metals in the ISM.
We can potentially disentangle the evolution effects by adding information on the chemical abundances of several elements in the gas-phase and locked up in dust grains. Oxygen primarily forms in high-mass stars, whereas nitrogen can form in low and intermediate-mass stars. Oxygen is also commonly suggested to accrete more efficiently onto dust grains, whereas nitrogen remains in the gas-phase.
The talk will showcase spatially resolved radial gradients of the stellar mass, gas mass, and dust mass surface density, and O/H and N/O elemental abundance ratios for local spiral galaxies NGC628 (M74), NGC5457 (M101), NGC598 (M33), and NGC300. I will present the results of chemical and dust evolution models capable of disentangling the different evolution mechanisms within these galaxies consistent with previous claims such as inside-out growth.
Understanding the stellar mass build-up and evolution of the surprisingly massive galaxies in the Epoch of Reionization (EoR) requires insight into their molecular gas reservoirs, which fuel star formation. I will present new deep VLA observations of REBELS-25 (z = 7.31), a massive star-forming galaxy and the highest-redshift dynamically cold disk (V_rot,max/σ ≃ 11) confirmed to date. Using ~40 hours of VLA observations, we detect CO(3-2) line emission, providing the first direct measurement of the cool molecular gas in a star-forming galaxy at z > 7. The measured line flux translates to a CMB-corrected molecular gas mass of (1.3 ± 0.7) × 10¹¹ M_sun, indicating that REBELS-25 hosts a massive molecular gas reservoir already ~700 Myr after the Big Bang. We also derive a high gas fraction of ~95% and a depletion time of ~0.65 Gyr. The latter is consistent with extrapolated trends from significantly lower-redshift main-sequence galaxies. We find that the CO- and [CII]-based gas masses are consistent within 1σ, supporting the use of [CII] as a gas-mass tracer for star-forming galaxies in the EoR.
Additionally, recently obtained ALMA data allow us to detect CO(7-6) emission, providing constraints on the excitation ratio and ISM properties through detailed modeling. Upcoming JWST NIRCam grism observations will further enable us to study ionized gas kinematics via [OIII] λ5007 and compare it to the cool gas dynamics traced by [CII]. This will test whether the extreme rotational support seen in [CII] is consistent with the warm ionized gas, shedding light on how rotationally supported systems form so rapidly.
These results highlight the detectability of low-J CO emission even at z>7, paving the way for next-generation instruments, and stress the importance of the synergy between different facilities in providing critical insights into the rapid mass assembly of massive galaxies during the first billion years of cosmic history.
This talk introduces ShadowSWIFT, a novel moving-mesh hydrodynamical code for large-scale cosmological and galaxy simulations, developed within the SWIFT collaboration. SWIFT is a highly optimised and scalable software that allows hydrodynamical solvers to use multiple subgrid routines. ShadowSWIFT is currently compatible with the EAGLE and GEAR subgrid routines, and is expected to release fully this year. This presentation will cover demonstrations of ShadowSWIFT's efficacy, ranging from simpler test cases for hydrodynamical setups, to more complex setups with evolving galaxies with star formation, feedback, and cooling, to cosmological simulations. ShadowSWIFT comes with a partner software that allows for the creation of moving-mesh friendly initial conditions from those that might be typically used in SPH simulations, allowing for direct comparisons between SPH and moving mesh. Some results of these comparisons will demonstrated, along with the pitfalls of these direct comparisons. ShadowSWIFT will be a new and exciting simulation code that is publicly available through the SWIFT download. The talk will conclude with an outlook on additional features, conservation techniques, and timelines for public availability.
The chemical composition of tidally locked gas giant atmospheres is the result of an intricate balance between the temperature, the wind dynamics, and the incident radiation coming from the host star. As such, the planet can show distinct atmospheric signatures dependent on the phase during which it is observed. Now, with the unprecedented sensitivity of the James Webb Space Telescope, we can finally gain insight into the true complexity of the physics and chemistry of planetary atmospheres.
During this presentation, we will present a suite of one-, two-, and three-dimensional photochemical models, exploring in detail the chemistry of the hot Jupiter WASP-43 b. We will compare our results to existing James Webb data of Bell et al. 2024, and explain the intriguing absence of atmospheric methane in this planet.
High-resolution spectroscopy (HRS) is a powerful tool for studying the atmospheres of planetary-mass objects, including brown dwarfs and exoplanets. By analysing the fine details in near-infrared spectra, we can detect absorption features from key molecules and their isotopic variants, revealing the chemical composition of these sub-stellar objects. Such measurements offer clues about their formation history and provide insights into dynamic atmospheric processes such as vertical mixing. Additionally, broad absorption lines of sodium and potassium serve as indicators of surface gravity, but fully interpreting these features requires accounting for subtle distortions in their shapes. HRS also allows us to study cloud properties, including atmospheric variability and surface inhomogeneities.
To illustrate the power of HRS, I will present an analysis of multi-wavelength CRIRES+ spectra of Luhman 16AB, the closest known brown dwarf binary, observed as part of the ESO SupJup Survey. These findings demonstrate the exciting potential of HRS to improve our understanding of sub-stellar atmospheres and pave the way for future studies of lower-mass exoplanets with next-generation telescopes.
The equatorial jets observed on the Jovian planets—Jupiter, Saturn, Uranus, and Neptune—exhibit extreme zonal flow patterns, manifesting as either strongly prograde or strongly retrograde (Ingersoll, 1990). Existing theories have often treated gas giants and ice giants separately, primarily focusing on the shallower atmospheric layers of the ice giants (e.g., Schneider and Liu, 2009; Liu and Schneider, 2010). However, recent gravity measurements suggest that the convective envelope of Jupiter may be proportional to those of the ice giants, challenging the distinction between these planets (Kaspi et al., 2018). We present results from a numerical simulation introducing a unifying mechanism that can explain the equatorial jets on all four Jovian planets. In these simulations, as shown theoretically by Busse et al. (e.g., Busse, 1994) and numerically by many studies (e..g., Christensen, 2001; Jones et al., 2003; Heimpel et al., 2005; Jones and Kuzanyan, 2009; Kaspi et al., 2009; Gastine et al., 2013), the convective dynamics and planetary rotation of these planets drive the formation of tilted convection columns. These columns, extending cylindrically from the deep interior to the outer atmospheric layers, play a crucial role in shaping the zonal wind patterns. In this study, the tilting of the convection columns introduces asymmetries in momentum transport, leading to the bifurcation of the flow into either superrotation (prograde jets) or subrotation (retrograde jets). Through a detailed analysis of the convection-driven columnar structures, we demonstrate that the equatorial wave properties and the leading-order momentum balance share remarkable similarities between the two types of solutions. Our findings comprehensively explain the potential for both superrotation and subrotation solutions under constant physical conditions, thereby explaining the diverse zonal wind patterns observed on the Jovian planets and providing a deeper understanding of the mechanisms driving equatorial jet formation.
HD 135344 is a visual binary system that is best known for the protoplanetary disk around the secondary star. Various substructures, such as a cavity and spiral arms, point to ongoing planet formation, but putative planets have remained hidden. The circumstellar environment of the A-type primary star, on the other hand, has evolved faster as inferred from the absence of accretion and significant infrared excess. I will present the discovery of a young giant planet in orbit around HD 135344 A. This object is the youngest directly detected planet that has fully formed and orbits on solar system scales. I will show results on the first characterization of its atmosphere, bulk parameters, and orbit, based on 4 years of VLT/SPHERE and VLTI/GRAVITY data. I will also discuss the challenges that we faced to disentangle orbital from background motion. HD 135344 Ab provides a unique window to a young giant planet shortly after formation, without any obscuration by circumstellar dust. The HD 135344 binary system shows that planet formation and disk evolution timescales can differ for two coeval stars within the same environment.
Recent direct imaging surveys like YSES and BEAST have revealed a population of young, super-Jupiter exoplanets at extreme distances from their host stars (>100 AU). These discoveries challenge planet formation theory which struggles to explain how such massive planets are formed so far away from their stars. Proposed mechanisms include in-situ formation through cloud fragmentation or disk gravitational instability, both of which occur on short timescales (~10,000 years). If these proposed processes are responsible, then the frequency of these wide-orbit planets is expected to remain consistent across different stellar ages. The WiSPIT survey, a snapshot survey targeting 178 solar-mass stars significantly younger than those covered by previous surveys, puts this to the test. We present one of the exciting first results of this survey: two wide-orbit gas giants around solar-type binary WiSPIT 1 with estimated masses of ~$10\,\mathrm{M_{J}}$ and ~$4\,\mathrm{M_{J}}$. This marks the first direct detection of a multi-planet system around a solar-type binary, offering new insights into planet formation at wide separations.
Wide field surveys searching for transiting exoplanets also record and discover both known stellar variability and previously unknown phenomena. Deep and complex eclipses of otherwise unremarkable stars reveal eclipsing companions that have complex substructures. The ASAS-SN survey has now produced over a dozen complex eclipses that last from weeks to years, and we present our analyses of several of these light curves, including a multi-year ringed disk transit and more recently two eclipses that are indicative of ringed disks in transit. Future wide and deep time domain surveys, such as the Vera C. Rubin Telescope and the upcoming release of Gaia DR4, will considerably increase the number of these objects.
Numerous theoretical studies within the modern cosmological framework suggest that gas accretion from the intergalactic medium is essential to feed star formation in galaxies throughout cosmic time. However, the way gas accretion takes place is still poorly understood as a direct evidence of it is still lacking. In some models, gas accretion is expected to take place in the outer discs of galaxies, from where it should be transferred to the inner star-forming discs through radial flows. Finding such flows and quantify them opens, therefore, the exciting possibility to infer the detailed properties of the accreting gas. Unfortunately the detection of radial flows presents a significant challenge due to the magnitude disparity between the radial and rotational velocities. Additionally, the distortions in velocity fields produced by these flows bear similarities to the effects of warped structures, further complicating their quantification. To address this, we have developed a new methodology to measure radial velocities and quantify mass flow rates in disc galaxies. This method employs the 3D kinematic software, 3D-Barolo, and incorporates a bootstrapping approach to estimate errors. We validated this approach using mock data from local galaxies in hydrodynamic simulations. In our analysis, we found that some galaxies exhibit azimuthal uniform radial inflows, but other galaxies display non-uniform radial flows, with variations in flow patterns. We also applied the method to some local galaxies and examined whether radial accretion inflows alone are sufficient to maintain the current rate of star formation in the inner regions of local spiral galaxies.
In this talk, I will introduce the Resolved Cluster Evolution Sunyaev-Zeldovich Survey (ReCESS): a 200-hour-plus observing campaign aimed at resolving the intracluster medium (ICM) through the thermal Sunyaev-Zeldovich (tSZ) effect in 25 ACT-selected galaxy clusters within a redshift range of 1.2 < z <2.0 using MUSTANG-2 on the GBT and ALMA. I will present the first results on the average tSZ-derived pressure distribution of the ICM at z>1.2, mapped from the core (inner 80 kpc) to the virial radius, by combining high-resolution data with ACT observations. Whenever available, we incorporate X-ray observations into our forward modeling routine to obtain a full thermodynamic picture of the ICM. I will illustrate this method through a case study of a cluster at z=1.7, for which excellent XMM-Newton, Chandra, and ALMA data are available. Finally, ReCESS enables the search for and study of shocks, mergers, and feedback mechanisms at an epoch when the ICM is still forming. While not all observations have been completed, we have identified several extremely interesting clusters with unique ICM morphologies, including the detection of a “tSZ cavity” at z=1.3, only the second tSZ cavity ever detected.
Mass and angular momentum regulate most of their formation and evolution of galaxies, including their morphological, kinematic, and star-forming properties.
In this talk, I will present our recent results characterising the angular momentum of the molecular gas in nearby disc galaxies. Exploiting data from the PHANGS-ALMA survey, we have performed the first statistical study of the molecular gas specific angular momentum–mass ($j_{\rm H_2}-M_{\rm H_2}$) relation, finding for the very first time a well defined scaling law of the form $j_{\rm H_2}\propto M_{\rm H_2}^{0.53}$. The $j_{\rm H_2}-M_{\rm H_2}$ relation closely mirrors that of the stellar component (the Fall relation, $j_{\ast}$–$M_{\ast}$), highlighting the strong dynamical link between molecular gas and stars.
We contrast our findings against theoretical models, and we find that our observations cannot be fully explained by simple disc stability models; but instead the relation is better reproduced by more complex physics as implemented in the Shark semi-analytical model. Our findings establish the $j_{\rm H_2}-M_{\rm H_2}$ relation as a new benchmark for galaxy evolution models and a key reference for upcoming high-redshift studies of cold gas dynamics.
We present two new radio continuum images obtained with Apertif at 1.4 GHz. The images, produced with a direction-dependent
calibration pipeline, cover 136 square degrees of the Lockman Hole and 24 square degrees of the ELAIS-N fields, with an average
resolution of 17×12′′ and residual noise of 33 μJy/beam. With the improved depth of the images we found in total 63692 radio
sources, many of which are detected for the first time at this frequency. With the addition of the previously published Apertif catalog
for the Boötes field, we cross-match with the LOFAR deep-fields value-added catalogs at 150 MHz, resulting in a homogeneous
sample of 10196 common sources with spectral index estimates, one of the largest to date. We analyze and discuss the correlations
between spectral index, redshift, linear sources size, and radio luminosity, taking into account biases of flux-density-limited surveys.
Our results suggest that the observed correlation between spectral index and redshift of active galactic nuclei can be attributed to the
Malmquist bias reflecting an intrinsic relation between radio luminosity and the spectral index. We also find correlation between
spectral index and linear source size with more compact sources having steeper spectra.
Coronal mass ejections (CMEs) are a dominant contributor to space weather in the Solar System, with the potential to erode planetary atmospheres. While traditional stellar activity indicators, such as flares, do not confirm the presence of a CME, Solar studies have established that Type II radio bursts provide a direct signature of CME-driven shocks. However, despite extensive searches, no unequivocal detection of an extrasolar Type II burst has been made, until now.
In this talk I will present 140 star-years of observational stellar data from the Low-Frequency Array Two Metre Sky Survey. In particular, I will present the first two extrasolar analogues of a Solar Type II burst that signals the presence of a CME. I will detail how such a detection fits within the Solar paradigm, and its implications for how common such events are on stars other than our Sun. At the end, I will outline a search for extrasolar (so-called) type-III bursts that trace energetic particle events.
Population III stars were the first generation of stars that formed in the Universe out of primordial gas. Thanks to JWST, we are now in an era where observing campaigns to discover Pop III stars has become a possibility. Over the last 3 years, several proposals on Pop III stars (from star cluster to galaxy scales) have been successful in getting time on JWST, however no convincing detections have resulted yet. The two most pertinent challenges are: 1.) if most Pop III stars were massive, they would have not survived for a time window long enough for JWST to capture them, and 2.) if they formed at redshifts > 15, which even with the sensitivity of JWST remains notoriously hard to observe.
There has been a longstanding idea that revolves around a 'low' redshift mode of Pop III star formation, which has recently garnered support from state of the art cosmological simulations. These simulations find copious amounts of pristine gas down to the end of Epoch of Reionization (EoR, z ~ 6), which could potentially harbour Pop III stars. If realistic, this could be a game changer since the natural expectation is that such Pop III stars would have been less massive, lived to a longer time period, and are located at cosmological distances within the reach of instruments aboard the JWST.
Motivated by these possibilities, we carry out the first 3D radiation magnetohydrodyamics simulations of Pop III star formation during the EoR. We find significant differences in the mass, multiplicity, radiation and cluster properties of Pop III stars between z = 6 and z > 15. Contrary to expectations, even though the gas is colder at z = 6, there is less fragmentation within the pristine cloud due to the combined effects of magnetic fields and radiation feedback. Differences in protostellar accretion rates at z = 6 and z > 15 lead to very distinct stellar evolution, which changes the amount of ionizing and dissociating photons produced, and subsequent escape fractions. The differences are even more dramatic when a background Lyman-Werner radiation appropriate at z = 6 is included. The differing nature of the low redshift mode of Pop III star formation is expected to modify spectral signatures, which are currently not accounted for in Pop III population synthesis models.
By providing realistic, full physics-guided estimates of the mass and radiation properties of these stars, our simulations provide much needed benchmarks for designing Pop III observing campaigns with JWST towards the end of the first billion years.
Many close-in exoplanets are expected to orbit inside the Alfvén surface of the stellar wind, the region where the stellar wind is dominated by the stellar magnetic field. In this scenario, the planet acts as an obstacle to the stellar wind flow, leading to an electromagnetic coupling between the star and the planet. The energy fluxes arising from this interaction can power enhanced emission in the stellar chromosphere, as observed in several systems. However, the exact physical mechanisms responsible for energy transfer remain uncertain.
Here, we present a study of magnetic star-planet interactions using 3D magnetohydrodynamic simulations of a magnetised hot Jupiter. The simulations incorporate stellar heating, tidal forces, and a magnetised stellar wind, providing the key physical ingredients needed to model these interactions self-consistently. Our simulations reveal the presence of Alfvén wings, which can carry a Poynting flux toward the star. We show that the size of the interaction region depends on the relative topology between the stellar wind field and the planetary field, with more aligned configurations producing larger Alfvén wings, while anti-aligned cases result in a weaker coupling.
Additionally, we provide scaling laws for the power generated by the interaction as a function of the planetary magnetic field strength, allowing for direct comparisons with analytical theories. These scaling relations offer a means to link observed star-planet magnetic interaction signals to planetary magnetic field strengths, providing a method to probe exoplanetary magnetism.
Context. Type III solar radio bursts are among the most common radio emissions from the Sun, produced by energetic electron beams propagating through the solar corona and interplanetary space. These bursts are characterized by their rapid frequency drift, and through them, we can further study solar activity. Since the launch of ESA’s Solar Orbiter mission in 2020, the Radio and Plasma Waves (RPW) instrument has collected more than four years of data, but identifying Type III bursts remains a challenge due to their varying intensities and morphologies. While efforts for automated algorithms exist, they often struggle with faint or more complex bursts. Human participation can help optimize automated Type III detection.
Aims. We aim to create the first extensive catalog of Type III solar radio bursts detected from space, including precise time and frequency ranges for each identified event. This catalog will serve as a valuable resource for studying the relationship between Type III bursts and solar flares, as well as their variability throughout the solar cycle.
Methods. To achieve this, we developed Solar Radio Burst Tracker, a citizen science project hosted on Zooniverse.org, where volunteers analyze spectrograms from the RPW instrument and identify Type III bursts. Each spectrum is classified by eight participants to ensure accuracy. In addition, we developed a post-processing analysis algorithm where we can filter the noise from the volunteers’ classifications and provide a measure of uncertainty to their identifications.
Expected Outcomes. We present the design of the project and the initial results from the first phase of classifications. The dataset will be compared with X-ray observations of solar flares, helping to establish a connection between radio bursts and flare-associated electron acceleration. Additionally, the project is planned to be extended to incorporate STEREO spacecraft data, further expanding the catalog and allowing for long-term studies of solar radio emissions over the solar cycle. We also plan to provide this catalog to optimize automatic Type III detection for future observations.
The Solar and Heliospheric Observatory (SOHO) Extreme-ultraviolet Imaging Telescope (EIT) has been taking images of the Solar disk and corona in four narrow EUV bandpasses (171, 195, 284, and 304 angstroms) at a minimum cadence of once per day since early 1996. The time series of fully-calibrated EIT images now spans approximately 28 years, from early 1996 to the early 2024, covering solar cycles 23 and 24 in their entirety, as well as the beginning of cycle 25. We have extracted Sun-as-a-star light curves in each of these four bands. I will present the results and discuss their implications for studies of activity on other stars, as well as the utility of UV observations for exoplanet detection and studies of exoplanet habitability.
Expect all poster presenters to be there so the poster price committee can ask questions
Light pollution not only disrupts ecosystems and human health but also severely impacts astronomical observations by increasing skyglow, limiting our ability to study the universe. DARKER SKY is an Interreg North Sea project dedicated to reducing light pollution to enhance biodiversity and ecological connectivity across the North Sea region. It has a budget of €4.2 million and involves 13 partners from four countries, including the Kapteyn Astronomical Institute, which plays a vital role in astronomical monitoring and public outreach.
DARKER SKY develops innovative measurement, monitoring, and co-design methodologies to assist municipalities in implementing effective light reduction strategies. It facilitates interdisciplinary knowledge exchange by sharing best practices learned from nine demonstrator sites featuring environmentally friendly lighting solutions. By involving astronomers, ecologists, sociologists, policymakers, and local communities in co-design processes, the project ensures that solutions balance ecological preservation, public needs, and scientific interests.
In this presentation, we will share the first results of our project to reach underrepresented school children with our interactive planetarium shows. The NOVA Mobile Planetarium project started in 2010 and has reached approximately 500,000 school children to date. However, data collected over the period 2010-2023 showed that certain regions and groups were underrepresented. Therefore, in 2024 we started offering free school visits to regions outside the Randstad and to underserved neighborhoods in large cities. We have also developed and tested an innovative training course for our planetarium staff to make their teaching more responsive to the wishes and needs of more diverse audiences. The project is funded by the NWA. In addition to representatives of the astronomical institutes, our main project partner is the IMC Weekend School Foundation.
Enriching press releases and social media posts with short videos is becoming increasingly important. In 2024, the NOVA Information Center experimented with content creation. For example, we produced one-and-a-half minute videos in which we interviewed three researchers per video. In these videos, we also included b-roll footage of telescopes and astronomical phenomena. In this presentation, we share our experiences and discuss them with the audience.
A few tips in advance:
1.You can film very well with a cell phone. However, secure your phone to a tripod or a pile of books.
2. Sound is important. Make sure you have a lavalier or wireless microphone.
3. Write a script in advance but dare to deviate from it. Scientists don't memorize their lines. That's okay. It makes it more spontaneous.
4. ESO, ESA and NASA are great resources for b-roll material.
5. Think about the placement of titles and subtitles. We had the text at the bottom, but on social media that clashes with other information.
6. Editing is a skill. We outsourced the editing.
We would like to present the Black Hole Render Engine for the industry standard, open-source, 3d graphics software Blender. Our render engine has two unique capabilities. First it is able to render images of textured meshes at arbitrarily close and far away positions to a black hole. Secondly, the camera can be freely orientated in spacetime and placed anywhere between far away (for research use cases) and very close to the black hole (for educational and outreach purposes). We made a custom Python package called curvedpy to calculate photon geodesics, which is based on peer-reviewed techniques in general relativity. These geodesics are used in the render engine to trace rays around both static (Schwarzschild) and rotating (Kerr) black hole spacetimes. The Render Engine is also compatible with established astronomical codes like kgeo, used for analysis of astronomical observations of black holes with telescopes like the Event Horizon Telescope. The Black Hole Render Engine as well as curvedpy are open source and freely available on github (https://github.com/bldevries/curvedpy) and the pypi repository.
I can't submit this as a general talk even though I'm the secretary of the society and the web host (the Dutch love their NOVA networks). Meanwhile I still have more freedom of speech than my colleagues in the USA (where I lived and worked for 20 years) so I will submit and hope; While you read this abstract you're seeing it in the Communication and Education session I guess; are you there??
Well if youre reading the title, either you came to my talk -- or not -- I hope more people come and listen to this point in EDI -- Especially if you are a White Male of European heritage,,, me too, but we dont have to be Donalds!
The European Regional Office of Astronomy for Development (E-ROAD), part of the International Astronomical Union’s global OAD network, harnesses astronomy to drive societal progress and contribute to the United Nations Sustainable Development Goals (SDGs). Based at Leiden University, E-ROAD focuses on quality education (SDG 4), gender equality (SDG 5), economic growth (SDG 8), and reducing inequalities (SDG 10) through collaborative initiatives across Europe.
This talk will highlight E-ROAD’s efforts in supporting capacity-building programs, strengthening scientific communities across Europe, and fostering collaborations that connect astronomers, educators, and policymakers. By showcasing ongoing projects and future opportunities, I will discuss how astronomy can be a powerful tool for sustainable development, expanding its impact beyond academia.
In this talk, I will give an overview of the IT research services at SURF that are relevant for astronomy research. In paricular, which solutions are there for large-scale simulations, high-throughput data processing and data storage and management? And how can you get (free) access to the national Computing facilites at SURF or, for even larger needs, to Europe’s fastest supercomputer LUMI.
Pulsar Timing Array (PTA) projects hold the promise of becoming sensitive Gravitational-Wave (GW) detectors in the nanoHertz frequency band. Multiple international PTA collaborations are actively timing an array of pulsars with their respective radio observatories, and each collaboration carries out GW searches in their own data. In principle, a combined search over all available PTA data is much more sensitive than what the individual PTA collaborations can achieve. However, combining the dataset is an involved project that takes years. The international combined GW searches have therefore historically lagged behind the individual PTA results by years, and are actually effectively less sensitive. I will show how to dynamically combine PTA datasets, which immediately increases the effective sensitivity of the entire international PTA community.
Fast radio bursts (FRBs) are bright, millisecond-duration radio transients with diverse morphologies and uncertain origins. As detection rates accelerate, manual classification becomes impractical. In this talk, I present a new framework for exploring FRB time-frequency structures using unsupervised machine learning techniques. We apply Principal Component Analysis (PCA) and a Convolutional Autoencoder (CAE) enhanced with an Information-Ordered Bottleneck (IOB) to both simulated and real FRB dynamic spectra, including high-time-resolution data from CHIME/FRB. PCA provides a fast, interpretable baseline for identifying broad trends and outliers, while the IOB-CAE excels at capturing complex, non-linear burst features with high reconstruction fidelity—even at low signal-to-noise. Using a newly developed FRB simulation tool, FRBakery, we evaluate these methods across diverse morphologies, demonstrating the potential of latent representations to reveal a continuum of FRB types and uncover subtle structure in large datasets. Our approach enables efficient, scalable analysis of FRB populations and provides a foundation for future classification efforts in the era of data-intensive radio astronomy.
We have recently opened a window on the seconds-to-minutes variable radio sky, and through these observations, a new source class of LPTs has begun to emerge. These new transients have emitted unknown radio flares with durations of seconds to minutes and periodicities of minutes to hours (Hyman et al. 2005; Hurley-Walker et al. 2022). These timescales imply that these transients exhibit coherent radio emission. Some have been associated with counterparts in the Milky Way, such as slowly rotating magnetars, while others have been identified as M dwarf–white dwarf binary systems. However, their nature remains uncertain, and more detection are needed to constrain these different hypotheses and better understand the origin of LPTs.
This is where LOFAR comes in. Its low-frequency band is sensitive to exotic coherent and polarized radio emission processes, and LOFAR’s ability to image very large fields with high sensitivity is unique. In particular, the LOFAR Two-Metre Sky Survey (LoTSS; Shimwell et al. 2017) aims to image the entire northern sky with unprecedented sensitivity and an angular resolution of 6″, probing a previously unexplored part of the radio sky. The survey has had two major data releases to date: DR1 with 58 pointings and DR2 with 814 pointings. LoTSS observes between 120 and 168 MHz.
Here we present our ongoing analysis of the LoTSS data to detect these rare bursts on timescales of seconds to minutes, using modern imaging techniques and fast filter analysis.
Indeed, a new theory on the origin of LPTs was sparked by the first detection of an LPT in LoTSS by de Ruiter et al. (2024), which turned out to be an M dwarf–white dwarf binary system with an orbital period matching the period of the radio pulses. In addition, our latest results are very promising, including the re-detection of a known RRAT (a very faint rotating radio transient with sporadic emission) multiple times in our data, strengthening our confidence in finding more of them.
Our next goal is to analyze more than 5% of the available data in the coming months to detect more of these LPTs. This project will serve as a foundation for the upcoming LOFAR 2.0, accelerating the real-time identification of these transients.
Unlucky stars that venture too close to a supermassive black hole (BH) get ripped apart by gravitational tidal forces. These tidal disruption events (TDEs) offer a rare probe of otherwise quiescent BHs.
TDEs are usually detected in the optical and ultraviolet (UV), where light curves show an early-time peak, often followed by a late-time plateau. Recent modelling shows that these plateaus arise when the stellar debris steadily accretes onto the BH, whereas the emission mechanism behind the peak luminosity is largely unknown. However, since TDEs are detected by their bright peak rather than their faint plateau, the peak emission mechanism must be understood to fully exploit the potential of TDEs to infer BH properties.
I present a correlation between the near-UV peak and plateau luminosities from the most recent dataset of 48 TDEs, which we have used to phenomenologically infer peak emission properties. In particular, we have investigated whether the poorly understood peak luminosity has a mutual parameter dependence with the well-modelled plateau luminosity, such as BH mass, inclination angle or stellar mass.
We conclude that a power-law relation between the optical/UV peak luminosity and BH mass can explain the correlation observed between the peak and plateau luminosity. Moreover, we find evidence that the peak luminosity depends on additional parameters, such as the viewing angle or the stellar mass. These findings rule out a subclass of models for optical/UV peak emission in TDEs.
Ground-based observations of spacecraft signals have been used to study space weather. However, single spacecraft measurements observed from the Earth have limitations in studying the structure and evolution of solar plasma as they are unable to differentiate spatial and temporal variations. To overcome this limitation and improve our understanding of interplanetary scintillation, we simultaneously observed radio signals transmitted by two co-orbiting spacecraft: the ESA Mars Express (MEX) and the Chinese National Space Administration Tianwen-1 (TIW-1). We conducted the observations from April to November 2021 using the University of Tasmania’s VLBI radio telescopes at 8.4 GHz. We employed the Planetary Radio Interferometer and Doppler Experiment (PRIDE) technique to determine the topocentric Doppler measurements and residual phase of the carrier signal. These observables were used to quantify the phase fluctuations of the spacecraft signals caused by solar wind and hydrodynamic turbulence in the interplanetary medium. The measured phase fluctuations RMS from both spacecraft show small differences which are caused by factors such as the spacecraft’s motion, onboard electronics, and variations in the uplink signal path through Earth’s ionosphere. These fluctuations decrease with solar elongation and correlate with solar radio flux at 10.7 cm (2800 MHz), indicating solar activity. The estimated total electron contents along MEX and TIW-1’s radio lines of sight are similar, with higher values at lower solar elongations. Simultaneous multi-spacecraft observations also enable RFI characterization, frequent spacecraft performance comparisons, and investigation of solar activity effects on spacecraft performance and scientific outcomes.
Direct imaging is a technique that allows us to spatially resolve the planet from its host star. Due to the big difference in flux between star and planet, a very high contrast must be reached to observe the planet that would be otherwise hidden in the glare of the star.
Coronagraphs are optical systems that work as angular filters, suppressing the on-axis star light and letting the off-axis planet light go through. A promising coronagraph is the Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC), which uses a set of aspheric lenses to apodize the entrance pupil without losses and a phase-shifting focal plane mask for the suppression. The lossless apodization allows us to maintain high throughput and achieve a small inner-working angle, unlocking the capability to search for planets at the diffraction limit. The masks are completely manufactured in-house at Leiden University with Nanoscribe, a micro-3D-printer that uses two-photon polymerization to achieve submicron precision in height. This manufacturing method allows us to print smooth structures, so, unlike lithography, it is not limited to a small number of etching steps.
In this talk, I will discuss the characterisation of the manufacturing process and show some preliminary results from the PIAACMC lab testing and on-sky observations with MagAO-X, an extreme adaptive optics instrument for the 6.5-meter Magellan Clay telescope at Las Campanas Observatory (Chile). This serves as a demonstration of the PIAACMC capability of observing exoplanets at close separations (~1𝜆/D) and at extreme contrast at the diffraction limit.
The design of the Multi-Object Spectrograph (MOS) for Astrophysics, Intergalactic-medium studies and Cosmology (MOSAIC) for the Extremely Large Telescope (ELT) is optimized for key capabilities such as high survey efficiency, high sensitivity to faint targets, and covering an extended parameter space, in terms of available modes (MOS & mIFU), bandwidth, spectral resolution, for the wavelength range from 390 nm – 1800 nm. The instrument is currently in phase B and had its System Architecture and Requirements Review in April.
NOVA leads the VISible spectrograph work package and manages the overall VISible Science Channel in close collaboration with other consortium partners. In this presentation, I move from a high-level overview of the instrument to describing the main characteristics of the VIS Science Channel, which is intended to have separate low- and high-resolution fibre link feeds, a dual-beam two-camera design to split the spectrum (in blue and red arms) providing full simultaneous coverage from 390nm—950nm in low resolution and multiple high resolution bands in the same wavelength range. I also provide an update on the current status of the project.
MICADO is a first light instrument for the Extremely Large Telescope. Together with an adaptive optics system, it will make supersharp images of the near-infrared sky (0.8-2.3 micron). The instrument is lead by the Max-Planck Institute for Extraterrestrial physics in Munich. NOVA contributes to this instrument, with the design and manufacturing of 2 filterwheels, a pupilwheel (including several kinds of pupil masks for high-contrast imaging and instrument alignment) , and an atmospheric dispersion corrector. The filterwheel- and pupilwheel-mechanisms are finished, have recently been tested in an cryogenic environment and have been validated. The ADC must still be manufactured and tested. NOVA plans to deliver the subsystem to MPE early 2026.
The Mid-Infrared ELT Imager and Spectrograph (METIS) is one of the first-light instruments for Europe’s Extremely Large Telescope (ELT). Covering the L, M, and N bands, METIS will offer imaging, coronagraphy, and medium-resolution spectroscopy across its full wavelength range (3-13 microns), as well as high-resolution integral field spectroscopy in the L and M bands (3-5 microns).
Following the successful Final Design Review, the METIS consortium—led by NOVA in collaboration with partners from across the globe—has now entered the critical construction phase. Subsystems are being manufactured, assembled, and tested, while preparations are underway for system Assembly, Integration, and Verification (AIV), set to begin later this year in Leiden. Meanwhile, ESO continues the construction of the ELT in parallel.
As the Mechanical Lead Engineer of METIS, I will present the progress of the instrument’s construction and the upcoming AIV phase, offering insight into the complexities and challenges of building an instrument for the ELT.
Astronomical instrumentation projects are often very international, with team members coming from different cultural backgrounds, being proficient in multiple different languages, working across different time zones, and frequently having a different (professional) understanding of the same – often English – working language.
In this talk, I would like to share my personal and professional experiences from working in the WEAVE Project over the past (nearly) 10 years, as someone with an astronomy-research-based background that has supported a pan-European project with 600+ members, through facilitating communication within and between the multiple nodes of the project, and helping to coordinate information flow between the two main halves of the project – the instrument-building project team, and the survey-led science team. I intend to open a discussion on the need for funding organisations, universities and research institutes, and projects to collectively acknowledge, appreciate and anticipate the need for such large projects to have properly financed project-support roles, and that these are valued as legitimate career-path options for those with the relevant skills, knowledge and expertise who also have a passion for building up, coordinating, and maintaining healthy communication (channels) within a project that crosses many borders.
The impetus for wide-field searches for counterparts of explosive transients including binary neutron-star mergers, supernovae, and tidal disruption events has never been higher. The ongoing operations with the LIGO-Virgo network of gravitational wave detectors in the 4th observing period continues to offer challenges for optical observers, primarily due to the poor (~100 deg$^2$) localisation regions. The Gravitational-wave Optical Transient Observer (GOTO; http://goto-observatory.org) network, featuring instruments in the Canary Islands and south-east Australia, is designed to overcome these challenges, and also offers high utility for searches and followup of other types of transients including gamma-ray bursts and supernovae. A modular design featuring eight 40-cm telescopes on each mount provides a composite field of view of around 40 square degrees per instrument, capable of promptly and autonomously covering large fields of view in response to observing triggers. I will report on the status and progress of the network and our expectations for the detection of future transients.
Ram pressure stripping, i.e. the advection of the interstellar medium (ISM) of galaxies experiencing a intracluster medium (ICM) wind, is a key process responsible for the environmental quenching of star-formation activity in galaxy clusters. This process also affects the non-thermal component of the ISM, i.e. the magnetic fields and cosmic rays, which can be probed in the radio continuum. In the past years, low-frequency radio observations, in particular with the Low-Frequency Array (LOFAR), were proven to be a well-suited diagnostic tool to identify ongoing ram-pressure stripping events. Furthermore, they allow us to infer or constrain key physical parameters such as the magnetic field strength in the disks and stripped tails and the (projected) velocity of the galaxies.
Statistical studies [e.g. Roberts+2024] found a connection between the presence of merger-induced ICM shocks and the quenching fraction in clusters, suggesting enhanced ram pressure stripping of galaxies in merging clusters.
In this talk, I will present results based on LOFAR observations at 54 and 144 MHz of the nearby merging galaxy cluster Abell 1367. This cluster hosts a complex of three peculiar ram-pressure stripped star-forming galaxies - all of them are over-luminous in the radio band with respect to their star formation rate and show long multi-phase tails. With our new observations, we measure the longest radio continuum tail to be ~350 kpc, more than a factor of three larger then the current record holder in the literature.
The three stripped galaxies lie in vicinity of an X-ray detected ICM shock wave and an associated radio relic, their tails are all oriented towards the direction of motion of the ICM shock. This, as well as the extreme properties of the galaxies, suggests that they suffer from enhanced stripping due to the ICM shock. I will present a test of this hypothesis based on a modelling of the spectral properties of the galaxies and their tails.
The interplay between gas accretion, feedback, and galactic dynamics plays a crucial role in shaping galaxy evolution. The MHONGOOSE survey, with its unprecedented HI sensitivity and high spatial resolution, provides a transformative opportunity to study these complex processes in nearby galaxies. By probing gas at extremely low column densities in the outskirts of galaxies, MHONGOOSE enables the detection and characterization of gas kinematics in regimes previously inaccessible. In this talk, I will discuss the kinematic properties observed across the diverse MHONGOOSE galaxy sample, ranging from systems with well-ordered kinematics to those exhibiting complex, disturbed dynamics, particularly evident at large radii and low gas column densities. Using high-quality rotation curves derived from 3D tilted ring modeling, I will discuss how this kinematic diversity can be quantified and investigate the potential origins of such diversity, including the roles of gas accretion, interactions, and internal processes.
The cosmic star-forming activity peaked at redshifts z=1-4 in the so-called "Cosmic Noon". This vigorous star production is driven by massive galaxies with star-formation rates 100-1000x higher than the Milky Way. However, it has long been unclear what causes these immense star formation: were early galaxies forming stars very efficiently, or are they simply more gas-rich than present-day galaxies?
Over the last decade, extensive surveys of cold gas in early galaxies have established that they are indeed very gas-rich. However, most of their cold gas resides in diffuse, extended reservoirs, contributing little to the observed star confirmation. Maybe early galaxies have significantly enhanced star-forming efficiency after all? To answer this question, we need to study the dense gas from which stars actually form.To do so, we need to target emission lines of "complex" molecules such as HCN, HCO+, and HNC.
Unfortunately, as these lines are very faint, dense gas at Cosmic Noon remains almost completely unexplored. I will showcase PRUSSIC: a comprehensive census of dense gas at high redshift with ALMA, NOEMA, and VLA. Over the last two years, PRUSSIC has detected dense gas in >20 early galaxies. We find that high-z galaxies contain surprisingly little dense gas and have an enhanced star-forming efficiency, a direct contradiction to previous models.
Most Active Galactic Nuclei (AGNs) are thought to contain a molecular and dusty torus that surrounds the accretion disk and obscures the AGN. The high angular resolution of the Atacama Large Millimetre/submillimetre Array (ALMA) allows us to resolve these tori for the first time, opening up the road to answering some long-held questions. One such question is the dynamics of tori and their surrounding structures: how are tori are formed? How are they fed? And how do they lose this material through outflows launched near the accretion disk?
In this talk, I will present high-resolution (down to 13 mas/0.3 pc) ALMA observations of the nearest Seyfert 2 type AGN located in the Circinus galaxy. These observations fully resolve the torus (size 2.4 pc) and show spiral structure in the surrounding circumnuclear disk (size ~28 pc), with two of these spirals connecting to the torus. We argue that this spirals structure is responsible for the inward transport of material to the torus and we constrain the associated feeding rate to be 0.7-15 M$_{\odot}$/yr, which suffices to fuel the AGN and the nuclear outflows. In the direction perpendicular to the disk, we reveal the morphology of the ionized outflow cone, for which we measure a launching radius of 0.16 pc, putting constraints on the still unknown launching mechanism.
If a system comes very close to a massive black hole it will be disrupted. The rate and type of these disruptions depends on the mechanism by which such a close passage occurs. We present new results showing that the axisymmetry of the potential of a galaxy (using the Milky way as an example) allows for chaotic orbits, a substantial fraction of which can dive arbitrarily close to the galactic center and be disrupted. We show that the rates of these collisionless disruptions may be significantly higher than the more conventionally studied collisional rate, caused by two body scatterings between systems. This has strong implcations for the ubiquity of exotic events like the flares from tidally disrupted stars and the production of hyper-velocity stars, in our galaxy and others.
DG CVn (GJ3789) is a famous, nearby (18pc) binary consisting of two young M4.0Ve red dwarf stars. It has been the source of the most luminous gamma flare event ever detected by Swift, and produces large flares in the optical and radio as well. Due to a maximum projected separation of only 0.2", it has been difficult to resolve optically, even for the Gaia mission.
One of the binary members is known to be radio loud, and we have studied the system with astrometric VLBI. With 7 new and 10 archival observations, spanning 18 years, we can show some spectacular results: We determine the full binary orbit of the system for the first time, and with unprecedented accuracy.
The Dust Settling Instabilty (DSI) is a member of the Resonant Drag Instabilities (RDI) family, and is thus related to the
Streaming Instability (SI). Linear calculations found that the unstratified monodisperse DSI has growth rates much higher than the SI
even with lower initial dust to gas ratios. However, recent nonlinear investigation found no evidence of strong dust clumping at the
saturation level. We perform a suite of 2D shearing box hydrodynamic simulations with the code Idefix, both in the mono- and polydisperse
regimes. We focus on the time evolution of the maximum dust density, noting the time at which the instability is triggered, as well as
analyse the morphology of the resultant structure. We found that the monodisperse DSI produces dust structure at densities high enough that likely leads to clumping. The polydisperse
DSI produces lower but comparable dust densities at the same spatial resolution. Our idealised treatment suggests that the DSI is
important for planetesimal formation, as it suffers less than the SI from including a dust size distribution.
The streaming instability is an efficient method for overcoming the barriers to planet formation in protoplanetary discs. The streaming instability has been extensively modelled by hydrodynamic simulations of gas and a single dust size. However, more recent studies considering a more realistic case of a particle size distribution show that this will significantly decrease the growth rate of the instability. We follow up on these studies by evaluating the polydisperse streaming instability, looking at the non-linear phase of the instability at the highest density regions, and investigating the dust size distribution in the densest dust structures. The polydisperse streaming instability is less efficient than its monodisperse counterpart in generating dense clumps that could collapse into planetesimals. In the densest dust structure, the larger dust sizes are more abundant because they are less coupled to the gas and, therefore, can clump together more than the smaller dust grains. This trend is broken at the largest dust size due to size-dependent spatial segregation of the highest-density regions, where particles with the largest Stokes numbers are located just outside the densest areas of the combined dust species. This is observed as a peak in the size distribution at the densest regions, which could relate to the size distribution that ends up in the planetesimal after collapse and can mimic the size distribution of dust growth.
Very Low Mass Stars (VLMSs) are the most abundant stars in our galaxy. The occurrence rate of Earth-like planets orbiting VLMS is higher than for higher-mass stars. Their planet-forming disks evolve fast, which makes them ideal laboratories to study Earth-like planet formation in the evolved disk. The faintness of VLMSs and the small sizes of their disks make their observations challenging. With its high resolution and sensitivity, the JWST/Mid-Infrared Instrument (MIRI) has enabled detailed characterization of the gas and dust. Within the MINDS JWST GTO program, 10 VLMS disks were observed. These disks exhibit a variety of dust spectral signatures: six showing clear silicate emission, three exhibiting dust-depleted spectra, and one appearing as an edge-on disk. In addition, all sources emit strong hydrocarbon gas emissions with a significant pseudo-continuum. We investigate the relation between disk evolution, silicate dust emission, and hydrocarbon optical depth. Our findings suggest: 1) as the disk evolves, grain growth and settling cause the dust opacity in the disk surface layers to decrease; 2) this allows us to look deeper in the disk; and 3) as we look deeper into the disk, the column density of hydrocarbons increases. These results highlight how the dust evolution influences the observation of gas emission in VLMSs.
Oxygen and carbon are key ingredients for the formation of planets. While planet-forming regions around T Tauri stars are typically oxygen-rich, planet-forming regions around very low-mass star (VLMS) are known to exhibit highly carbon-rich environments. Infrared spectroscopy provides a powerful tool to detect and quantify these essential building blocks in protoplanetary disks. In this talk, I will present an overview of water detections in the MIRI mid-INfrared Disk Survey (MINDS) JWST GTO program, with a particular focus on disks around VLMS. Our analysis reveals the first evidence of abundant water in several carbon-rich VLMS disks and shows that hydrocarbons can easily outshine water emission, leading to their carbon-rich spectral appearance. These results imply that planet-forming regions in VLMS disks can maintain high carbon-to-oxygen ratios (C/O > 1) while still harboring substantial water, potentially influencing the formation and composition of terrestrial planets around VLMS. Using full thermochemical disk models, we show that while the carbon-to-oxygen ratio (C/O) is an important factor influencing the mid-infrared spectral appearance, the absolute abundances of carbon and oxygen (C/H and O/H) play an even more significant role.
One of the most ambitious goals of modern astronomy is to uncover signs of extraterrestrial biological activity. This is, primarily achieved through spectroscopic analysis of light emitted by exoplanets to identify specific atmospheric molecules. Most exoplanets are indirectly identified through techniques like transit or Doppler shift of the host star's flux. Long-term surveys have yielded statistical insights into the occurrence rates of different planet types based on factors such as radius/mass, orbital period, and the spectral type of the host star. Initial estimations of terrestrial planets within the habitable zone have also emerged. However, the lack of detected light from these exoplanets leaves much unknown about their nature, formation, and evolution. Following the ”ESA-voyage 2050” call, the senior committee recommended the “characterisation of the temperate exoplanets” for a possible future Class L mission: “Answering the question of the existence and distribution of life elsewhere in the Universe has been an important driver for the exploration of other worlds, both in and outside of our Solar System.” As the number of detected rocky exoplanets around nearby stars rises, questions about their atmospheric composition, evolutionary trajectory, and habitability increase. Measuring the infrared spectrum of these planets poses significant challenges due to the star/planets contrast and very small angular separation from their host stars.
From previous research, it has been shown that space-based telescopes are mandatory, and unless large primary mirrors (>30m in diameter) can be sent into space, interferometric techniques become essential. These techniques, combining light from distant telescopes, allow access to information at minimal angular separation, operating within the diffraction limit of individual telescopes. Furthermore, nulling interferometry addresses the challenge of achieving a high contrast between the star and the planet, allowing for spectroscopic measurements of their atmospheres as well as reflected and thermal background light. This is done by the combination of the light coming from four telescopes with corresponding phase delays applied on each of the beams, resulting in the suppression of the incident light in the direction of the line of sight by destructive interference.
Despite successful demonstrations of nulling interferometry on the ground, a space-based mission has not been carried out yet but is vital to sidestep and tackle this scientific question. Even if technologically challenging, nulling interferometry has shown the highest potential in scientific return.
In this project, we explore different architectures and payload configurations for a four-telescope, single S/C interferometer (i.e using several apertures/telescopes with deployable structures, but avoiding a formation flying configuration).
At the core of a nulling interferometric mission is the beam combination. The choice of the four-beam combination scheme and phase shifting to supress the stellar light is manifold. In addition to theoretical studies on the effects of beam combination, chromaticity and polarization within a nulling interferometer, further experimental research is needed to complement the groundwork leading to future design choices. This challenge is being addressed at TUDelft, with a testbench dedicated to experimental studies on four beam, broadband (3-20μm) and polarization sensitive nulling interferometry. In addition to the experimental approach, our parametric study covers a range of 1-3 m for the diameter of the telescope and a 10-60 m baseline. The most promising concept working in the infrared range (3-20μm) will be highlighted. Launch constraints, tied to the use of an Ariane 6 launch vehicle, dictate the interferometer's size. This study is conducted by TUDelft in cooperation with KULeuven, CSL/ULiège, Amos and with the support of the European Space Agency. We will present the recent progress made to develop this mission concept and the related experimental activities.
The Advanced Telescope for High-Energy Astrophysics (Athena) has successfully completed a redefinition phase – both of the technical implementation, and mission driving science objectives – becoming ‘NewAthena’. With mission adoption by ESA foreseen in early 2027, the activities of the NewAthena Science Community are expected to ramp up in the very near term. I will give an update on the scientific priorities and prospects of this mission, also in light of novel results in high-energy high-resolution X-ray spectroscopy obtained from XRISM. I will also briefly highlight some of the technical progress achieved recently towards building the NewAthena X-ray Integral Field Unit detector, for which SRON is leading the implementation of the Focal Plane Assembly.
The Low Frequency Array (LOFAR) telescope is preparing for a major upgrade, known as LOFAR2.0. In 2025 and 2026 all 16.000 receivers, the station digital beam formers, clock distribution system, data network, correlator/beam former and central processing cluster will be replaced. On top, two new stations in Italy and Bulgaria will be built and added to the telescope.
LOFAR is a pan-European phased array radio telescope consisting of more than 100.000 small antennas. The LOFAR2.0 upgrade mitigates the biggest bottleneck of the telescope by upgrading the telescope’s digital beamforming systems, enabling the telescope to deliver more data, and increasing its scientific harvest. In particular, the LOFAR2.0 upgrade enables simultaneous full-resolution observing with all antennas in two frequency bands (10 – 80 MHz and 110-240 MHz). To keep up with the increased data rates and to enable future extensions, the data network is upgraded, as well as the GPU-based correlator and the postprocessing clusters.
The hardware and firmware design of the upgrade was completed in 2023. A LOFAR2.0 test station was realized as a qualification model to demonstrate compliancy of the design with the requirements. After the tests were successfully concluded in 2024, the hardware production for the full roll-out was started. In parallel, the white rabbit-based clock distribution system has been rolled-out to the first 5 LOFAR stations. Interferometric observations were run to measure the clock drift of all stations with respect to a reference station. The results show that the clock drift of the stations with white rabbit is reduced from 10s of nanoseconds to the order of 0.1 ns over 8 hours.
This contribution presents an overview of the LOFAR2.0 upgrade, its status, and measurement results of the test station and clock distribution system.
After more than 30 years of talking, the construction of the Square Kilometre Array (SKA) is now well underway. In this talk, I will give a update on construction, discuss how anyone can get involved in the SKA now, and what this stage of project development means for the Dutch astronomy community. In particular, I will focus on the establishment of our own regional centre, and its expected role in the community. NAC is the ideal forum to present this information considering the community investment in the project and the current important developmental stage the SKA.
The NOVA Submillimeter (submm) Group was established at the Kapteyn Astronomical Institute in 1998 as part of the Netherlands Research School for Astronomy (NOVA) instrumentation effort. Its primary goal was to develop technology for the ALMA project. This focus shaped the group's research and development direction, particularly in the field of low-noise heterodyne receivers for submillimeter wavelengths.
The group's first project was the development of ALMA Band 9 (602–720 GHz) receivers for ALMA’s first light. In collaboration with TU Delft, the group successfully demonstrated quantum-limited sensitivity, which led to securing an ESO contract for a series of ALMA receivers. Following the successful completion of the ALMA Band 9 project, the group continued its involvement with ALMA by contributing to the development of ALMA Band 5 and ALMA Band 2 receivers in collaboration with the GARD group in Sweden and INAF in Italy.
Over time, the group has gained expertise not only in submillimeter receiver development but also in the organization, testing, and small-scale production of high-quality astronomical receivers. This expertise has enabled participation in a range of projects beyond submillimeter astronomy, including optical (BlackGEM) and high-energy astrophysics (Cherenkov Telescope Array, CTA), all of which require precision instruments manufactured in small series.
In this presentation, we will discuss the group’s current activities, including the final stages of the ALMA Band 2 project, the development of the African Millimeter Telescope front-end, and the setup of a series production line for CTA cameras. Additionally, we will outline our strategy for major future submillimeter projects, beginning with the ALMA Wideband Sensitivity Upgrade (WSU) within the framework of ALMA’s guaranteed observing time program, and touching upon the technology development for the Atacama Large Aperture Submillimeter Telescope (AtLAST).
Expect all poster presenters to be there so the poster price committee can ask questions
Expect all poster presenters to be there so the poster price committee can ask questions
The Habitable Worlds Observatory (HWO) is the next flagship of NASA, planned to be launched in the 2040s. With a wavelength coverage from the ultraviolet to the near-infrared and a suite of multi-purpose instruments, this observatory will be a successor to the Hubble Space Telescope. It will be the first space telescope designed specifically to directly characterize Earth-sized exoplanets within the habitable zones of nearby stars, but its capabilities will also enable transformational observations for general astrophysics. The telescope and instrument requirements are currently being developed and it is expected that Europe/ESA will contribute in some way to the HWO instrumentation. In this talk, we will discuss the route towards a Dutch science and technological contribution to HWO.
Gaia is revolutionising our understanding of the Milky Way and can be used for research in many different areas of astronomy, ranging from solar system science to quasars. One field where the Gaia astrometry excels is the study of so-called runaway stars. Runaway stars move away from their birth region with a high peculiar velocity. The high-mass runaway stars can efficiently and effectively deposit their feedback into the interstellar medium, and can therefore significantly affect the ambient medium. The production rate and properties of high-mass runaway stars has been a topic for decades now and is hotly debated. In this talk, we will show how we have used Gaia DR3 to find 55 high-mass runaway stars ejected from the young cluster R136, situated in the starburst region 30 Doradus in the Large Magellanic Cloud (Stoop et al. 2024, Nature, 634, 809). The large number of high-mass runaways allow us to investigate the early evolution of the cluster. We found that 23-33% of the most luminous stars initially born in R136 are runaways. We show how these new insights have major implications for N-body simulations of young clusters and for hydrodynamical simulations of the interstellar and galactic medium. We will highlight the many key results that have been obtained on the topic of high-mass runaway stars over the past few years with Gaia in the Milky Way and Magellanic Clouds. Last, we will show what the exciting opportunities are with the upcoming Gaia DR4 in this field.
Constraining the Epoch of Reionization remains one of the pivotal tasks of modern cosmology, and next-generation telescopes are opening up the path to the first precision constraints on the timing of reionization derived from the Lyman-$\alpha$ damping wing signature imprinted on the spectra of high-redshift quasars by the foreground neutral intergalactic medium (IGM). In the coming years, EUCLID will detect a number of high-redshift quasars never seen before, whose exquisite spectra collected by JWST will call for powerful statistical methods to infer precision constraints on the IGM neutral hydrogen (HI) fraction as a function of redshift.
We developed a state-of-the-art JAX-based Bayesian inference pipeline that allows us to disentangle the IGM damping wing from a quasar's unknown intrinsic spectrum, accounting for covariances across the full spectral range caused by IGM transmission fluctuations, quasar continuum reconstruction, and spectral noise. Besides the lifetime of the quasar, we infer a novel set of physical summary statistics that allows for a near-optimal extraction of the information carried by the Lyman-$\alpha$ damping wing about both timing and morphology of reionization. This comprises the HI column density within the first 100 cMpc from the quasar as well as the distance to the first neutral bubble before the quasar started shining. Besides constraining the global IGM neutral fraction, these statistics carry information about the morphology of reionization which currently remains unused in other state-of-the-art analysis frameworks.
After marginalizing out nuisance parameters associated with the quasar continuum, we find that we can constrain the HI column density within the first 100 cMpc of each individual quasar to 0.1 - 0.9 dex and its lifetime to 0.2 - 1.0 dex. By applying our procedure to a set of mock observational spectra resembling the distribution of EUCLID quasars with realistic spectral noise, we show that our method applied to upcoming observational data can robustly constrain the evolution of the IGM neutral fraction at the < 5% level at all redshifts between 6 < z < 11, and we present the first such constraints for high-z quasar spectra collected with JWST.
Understanding the processes that drive the quenching of star formation in galaxies is crucial for unveiling the mechanisms that shape galaxy evolution. Quenching transforms actively star-forming galaxies into passive systems on very short timescales of a few hundred Myr, influencing the overall structure, morphology, and chemical composition of galaxies across cosmic time. Investigating quenching helps address fundamental questions about the interplay between internal processes, such as feedback from active galactic nuclei or supernovae, and external factors like environmental effects in dense galaxy clusters or groups.
The Euclid mission is set to revolutionize our understanding of galaxy evolution by mapping both the Universe's large-scale structure and the internal structure of galaxies with unprecedented precision. As part of the first Euclid Quick Data Release (Corcho-Caballero+25), we investigated the star formation histories (SFHs) of galaxies at $0
In the nearby Universe (z<0.1), our analysis reveals consistent results with previous findings: approximately 70% of galaxies are classified as Ageing, 10% to 20% are Retired, and the remaining fraction (10%-20%) experienced a sudden truncation of star formation within the last Gyr. In terms of stellar mass, Ageing and Retired galaxies largely dominate the low- and high-mass ends. The fraction of Retired galaxies surpasses Quenched systems at stellar masses above $3\times10^{10} M_\odot$. The temporal evolution of these populations shows a rising fraction of Ageing galaxies and a decreasing fraction of Retired galaxies at higher redshifts. Interestingly, the Quenched fraction remains relatively stable across mass and redshift ranges.
In term of their physical properties, we explored the mass-size-metallicity relation for each population: Ageing galaxies align with disk morphologies and low stellar metallicities; Retired galaxies are compact and chemically enriched; and Quenched galaxies present an intermediate profile, more compact and evolved than Ageing systems. Despite possible selection biases, this work highlights Euclid's immense potential for shedding light on the physical mechanisms driving galaxy quenching and evolution.
Recently, we have with LOFAR successfully imaged several deep fields at sub-arcsecond resolutions (e.g. Lockman Hole, ELAIS-N1, and Boötes), revealing the distant universe below 200 MHz in unprecedented detail. However, this has come at the expense of significant computing resources and extensive manual intervention, making it unsustainable for large-scale surveys or ultra-deep wide-field imaging. In this talk, I will discuss recent progress in developing the LOFAR VLBI pipeline for wide-field imaging, techniques to reduce the computational costs by up to a factor of 10 for ultra-deep imaging, and replacing manual interventions with automation and AI, making us ready for the LOFAR 2.0 era.