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 Haystack Observatory
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
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