ORIGINS Black Hole Days

Session

The Galactic Center

GC

27 Oct 2025, 13:55

X5 1.1.18 (MPE, Garching)

39. The Black Hole in the Centre of the Milky Way

Frank Eisenhauer (MPE)

27/10/2025, 13:55

Black Holes are among the most mysterious objects in the Universe. They are so massive and compact that nothing - not even light - can escape their gravity. Our presentation will give an update on the overwhelming observational evidence for an extremely heavy and compact object in the Galactic Centre, for which a supermassive black hole is the best explanation. Using the world's largest...

28. Finding faint stars in the Galactic Center with GRAVITY

Felix Mang (Max Planck Institute for Extraterrestrial Physics)

27/10/2025, 14:20

Resolving the rich structure in the central 0.1 x 0.1’’ in the Galactic Center allows tracing stars orbiting the central massive black hole SgrA*. Serving as test particles in a strong gravitational field, these S-stars are susceptible to effects of General Relativity. With its unmatched astrometric precision, the interferometric beam-combiner GRAVITY has already facilitated in the past a...

7. Probing the gravitational potential around Sagittarius A* with stellar orbits

Matteo Sadun Bordoni (Max Planck Institute for Extraterrestrial Physics)

27/10/2025, 15:00

Since 2016, the GRAVITY interferometer at ESO’s Very Large Telescope has provided astrometric data with unprecedented accuracy for the S-stars orbiting Sagittarius A*, providing a powerful means to probe the gravitational potential surrounding the supermassive black hole at the center of our Galaxy. Notably, we have detected the in-plane, prograde Schwarzschild precession of the orbit of the...

24. Flares from SgrA*: Dynamical probes for the accretion flow around supermassive black holes

Diogo Ribeiro (Max Plank Institute for Extraterrestrial Physics)

27/10/2025, 15:15

Photons emitted from near ultra-compact objects carry information not only about their emission environment but also about the spacetime geometry around such objects. In the case of Sagittarius A*, the supermassive black hole at the centre of the Milky Way, the detected emission in the Near Infrared can flare to ten times its quiescent flux and be resolved temporally and spatially by the...

25. Polarization of reflected X-ray emission from Sgr A molecular complex: multiple flares, multiple sources?

Ildar Khabibullin (USM LMU, MPA)

27/10/2025, 15:30

Extended X-ray emission observed in the direction of several molecular clouds in the Central Molecular Zone (CMZ) of our Galaxy exhibits spectral and temporal properties consistent with the `X-ray echo' scenario. It postulates that the observed signal is a light-travel-time delayed reflection of a short ($δt<$1.5 yr) and bright ($L_{\rm X}>10^{39}~{\rm erg~s^{-1}}$) flare, most probably...

23. Feeding the Galactic Center: Understanding the G1-2-3 Gas Streamer

Simran Joharle (Max Planck Institute for Extraterrestrial Physics)

27/10/2025, 15:45

Sagittarius A*, the supermassive black hole at the center of our Galaxy, offers a unique laboratory to study black hole accretion at extremely low rates. Understanding what material is available to feed it, and how that material interacts with its accretion zone, is key to understanding black hole feeding mechanisms more broadly. Many gas clumps of the order of a few Earth Solar masses have...