GMVA17B-260

Imaging the Global Accretion and Outflow of Sgr A*: 3mm VLBI with GMVA+ALMA

Abstract

The Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), is the most promising target to study the dynamics and thermodynamics of black hole accretion and outflow via direct imaging. At 3.5mm, the emission from Sgr A* occurs within ~15 Schwarzschild radii of the black hole and is resolvable with the GMVA, but previous observations have had insufficient sensitivity and baseline coverage to study its detailed structure and evolution. We request two full-polarization GMVA+ALMA observations at 3.5mm, to complement our awarded 2017 observations. These observations will elucidate the long-standing question of whether the 3.5mm emission arises in an accretion disk or in a jet, they will be sensitive to intrinsic structural variability on timescales of hours, days, and a year, and they will provide critical guidance to interpret Event Horizon Telescope images on scales of only a few Schwarzschild radii.

Investigators

Name	Institution
GBT Operator	Green Bank Observatory
Atish Kamble	Center for Astrophysics | Harvard & Smithsonian
Laurent Loinard	México, Universidad Nacional Autónoma de
Antonio Hernandez	Max-Planck-Institut für Radioastronomie
Remo Tilanus	Arizona, University of
Gisela Ortiz	Max-Planck-Institut für Radioastronomie; México, Universidad Nacional Autónoma de; México, Universidad Nacional Autónoma de; Astrofísica, Óptica y Electrónica, Instituto Nacional de
Avery Broderick	Waterloo, University of
Raquel Fraga-Encinas	Nijmegen, Radboud Universiteit
Ciriaco Goddi	Center for Astrophysics | Harvard & Smithsonian; European Southern Observatory; Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium; Nijmegen, Radboud Universiteit
Tony Zensus	National Radio Astronomy Observatory; Max-Planck-Institut für Radioastronomie
Grant Wilson	Massachusetts at Amherst, University of
Michael Johnson *	California at Santa Barbara, University of; Center for Astrophysics | Harvard & Smithsonian
Christiaan Brinkerink	Nijmegen, Radboud Universiteit
Thomas Krichbaum	Max-Planck-Institut für Radioastronomie
Freek Roelofs	Center for Astrophysics | Harvard & Smithsonian; Nijmegen, Radboud Universiteit
Sera Markoff	Amsterdam, Universiteit van
Shep Doeleman	Center for Astrophysics | Harvard & Smithsonian
Lindy Blackburn	Center for Astrophysics | Harvard & Smithsonian
Cornelia Mueller	Würzburg, Universität; Nijmegen, Radboud Universiteit; Astronomical Institute of the University of Erlangen-Nuremburg
Geoffrey Bower	Academia Sinica
Heino Falcke	Netherlands Institute for Radio Astronomy; Nijmegen, Radboud Universiteit
Vincent Fish	Haystack Observatory
Monika Moscibrodzka	Nijmegen, Radboud Universiteit
Jason Dexter	Colorado at Boulder, University of
Keiichi Asada	Academia Sinica
Dimitrios Psaltis	Arizona, University of
Roman Gold	Maryland, University of; Perimeter Institute for Theoretical Physics; Syddansk Universitet
Hotaka Shiokawa	Center for Astrophysics | Harvard & Smithsonian
Michael Janssen	Max-Planck-Institut für Radioastronomie; Nijmegen, Radboud Universiteit
Sara Issaoun	Center for Astrophysics | Harvard & Smithsonian; Nijmegen, Radboud Universiteit
Rebecca Azulay	València, Universitat de
David Hughes	Astrofísica, Óptica y Electrónica, Instituto Nacional de
Kazuhiro Hada	Istituto Nazionale di Astrofisica; National Astronomical Observatory of Japan ; Nagoya City University
Motoki Kino	National Astronomical Observatory of Japan ; Korea Astronomy and Space Science Institute
Jonathan McKinney	Maryland, University of
Andrew Chael	Princeton University
Katherine Bouman	Massachusetts Institute of Technology; California Institute of Technology
Mareki Honma	National Astronomical Observatory of Japan
Kazunori Akiyama	Massachusetts Institute of Technology; Haystack Observatory
Rusen Lu	Max-Planck-Institut für Radioastronomie; Shanghai Astronomical Observatory, CAS
Michael Kramer	Manchester, University of; Max-Planck-Institut für Radioastronomie
Jim Cordes	Cornell University
John Wardle	Brandeis University
Richard Plambeck	California at Berkeley, University of
Jim Moran	Harvard University; Center for Astrophysics | Harvard & Smithsonian
Feryal Ozel	Arizona, University of
Dan Marrone	Arizona, University of
Junhan Kim	Arizona, University of; California Institute of Technology
Gopal Narayanan	Massachusetts at Amherst, University of
Chi-kwan Chan	Arizona, University of
Eduardo Ros	Max-Planck-Institut für Radioastronomie; València, Universitat de
Shami Chatterjee	Cornell University
Scott Ransom	National Radio Astronomy Observatory; Virginia, University of
Robert Wharton	Jet Propulsion Laboratory
Lia Medeiros	Arizona, University of

* indicates the PI