Speaker
Description
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.
| Talk category | NOVA Network 1 |
|---|---|
| Preference for a talk or poster | Talk |
