Speaker
Description
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.
| Talk category | NOVA Network 3 |
|---|---|
| Preference for a talk or poster | Talk |
