GMVA25A-145
Peering into M87's black hole in multiple colors with GMVA+APEX+LBA
Abstract
Recent EHT observations of M87 have revealed a ring-like structure at 1.3mm near the event horizon. The structure was interpreted as a photon ring surrounding a dark shadow caused by gravitational light bending and photon capture at the event horizon. The origin of the ring, however, needs to be better understood. The observed ring may also be the result of photons that are not entirely bound by black hole's gravity, such as those emitted by plasma located at a distance from the photon-capture radius. Our recent GMVA+ALMA observation of M87 suggest that a ring-like structure may also exist at 3mm. We propose new observations of M87 with GMVA+APEX+LBA at 7/3mm, which should be conducted in close proximity to EHT observations at 1.3/0.9mm. We will be able to obtain a multicolored (3/1.3/0.9mm) view of the black hole environment for the first time, allowing us to investigate the origin of the ring and the physical properties of plasmas within the innermost accretion flows and jets. Furthermore, we propose to locate the 7mm VLBI core with respect to the black hole, attempting to determine whether the core represents the outer parts of the accretion flows or is a tau=1 surface of the jet.
Investigators
| Name | Institution |
|---|---|
| Sang-Sung Lee | Korea Astronomy and Space Science Institute |
| Do-Young Byun | Korea Astronomy and Space Science Institute |
| Jamie Stevens | Australia Telescope National Facility |
| Cormac Reynolds | Commonwealth Scientific and Industrial Research Organisation |
| Philip Edwards | Australia Telescope National Facility |
| Chris Phillips | Australia Telescope National Facility |
| Fumie Tazaki | National Astronomical Observatory of Japan ; Tokyo Electron Technology Solutions Ltd. |
| Tomohisa Kawashima | Tokyo, University of |
| Kazuhiro Hada | Istituto Nazionale di Astrofisica; National Astronomical Observatory of Japan ; Nagoya City University |
| Hung-Yi Pu | Perimeter Institute for Theoretical Physics |
| Masanori Nakamura | Academia Sinica; National Institute of Technology, Hachinohe College |
| Keiichi Asada | Academia Sinica |
| Jongho Park * | Kyung Hee University |
| GBT Operator | Green Bank Observatory |
* indicates the PI