VLBA23A-118
Probing the Jet Base of M87 in the Time Domain
Abstract
Recent observations of M87 with the Event Horizon Telescope have revealed a ring-like structure near the event horizon. The corresponding linear polarization images indicate that a strong, ordered, and poloidal-dominated magnetic field may exist in the vicinity of the black hole, consistent with models of AGN jet launching. However, using only the 1mm images it is difficult to understand the origin of the ring and the physical properties of the innermost accretion flows and jet base. Our recent GMVA+ALMA observations of M87 indicate that there is also a ring-like structure present at 3mm in the core of the M87 jet. Here we propose to explore a new parameter space: the time domain. We propose new observations with a global VLBI array in two epochs near in time to the planned GMVA+ALMA observations in Spring 2023. We will be able to test the jet launching models and constrain the jet acceleration mechanism by combining the global VLBI observations with the GMVA+ALMA observations, which will probe the jet base on a monthly basis for the first time. In the 2022A semester, similar observations were attempted, but our science objectives could not be achieved because ALMA's hydrogen maser failed just before the observations.
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 |
| Philip Edwards | Australia Telescope National Facility |
| Chris Phillips | Australia Telescope National Facility |
| Feng Yuan | Shanghai Astronomical Observatory, CAS |
| Andrei Lobanov | Max-Planck-Institut für Radioastronomie |
| zhi-qiang shen | Shanghai Astronomical Observatory, CAS |
| Wu Jiang | Shanghai Astronomical Observatory, CAS |
| Hung-Yi Pu | Perimeter Institute for Theoretical Physics |
| Rusen Lu | Max-Planck-Institut für Radioastronomie; Shanghai Astronomical Observatory, CAS |
| Tomohisa Kawashima | Tokyo, University of |
| Jae-Young Kim | Max-Planck-Institut für Radioastronomie; Kyungpook National University |
| Thomas Krichbaum | Max-Planck-Institut für Radioastronomie |
| Kazuhiro Hada | Istituto Nazionale di Astrofisica; National Astronomical Observatory of Japan |
| Fumie Tazaki | National Astronomical Observatory of Japan ; Tokyo Electron Technology Solutions Ltd. |
| 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