Resolved magnetic-field structure and variability near the event horizon of Sagittarius A

Michael D Johnson; Vincent L Fish; Sheperd S Doeleman; Daniel P Marrone; Richard L Plambeck; John F C Wardle; Kazunori Akiyama; Keiichi Asada; Christopher Beaudoin; Lindy Blackburn; Ray Blundell; Geoffrey C Bower; Christiaan Brinkerink; Avery E Broderick; Roger Cappallo; Andrew A Chael; Geoffrey B Crew; Jason Dexter; Matt Dexter; Robert Freund; Per Friberg; Roman Gold; Mark A Gurwell; Paul T P Ho; Mareki Honma; Makoto Inoue; Michael Kosowsky; Thomas P Krichbaum; James Lamb; Abraham Loeb; Ru-Sen Lu; David MacMahon; Jonathan C McKinney; James M Moran; Ramesh Narayan; Rurik A Primiani; Dimitrios Psaltis; Alan E E Rogers; Katherine Rosenfeld; Jason SooHoo; Remo P J Tilanus; Michael Titus; Laura Vertatschitsch; Jonathan Weintroub; Melvyn Wright; Ken H Young; J Anton Zensus; Lucy M Ziurys

doi:10.1126/science.aac7087

Resolved magnetic-field structure and variability near the event horizon of Sagittarius A

Science. 2015 Dec 4;350(6265):1242-5. doi: 10.1126/science.aac7087. Epub 2015 Dec 3.

Authors

Michael D Johnson¹, Vincent L Fish², Sheperd S Doeleman³, Daniel P Marrone⁴, Richard L Plambeck⁵, John F C Wardle⁶, Kazunori Akiyama⁷, Keiichi Asada⁸, Christopher Beaudoin², Lindy Blackburn⁹, Ray Blundell⁹, Geoffrey C Bower¹⁰, Christiaan Brinkerink¹¹, Avery E Broderick¹², Roger Cappallo², Andrew A Chael⁹, Geoffrey B Crew², Jason Dexter¹³, Matt Dexter⁵, Robert Freund⁴, Per Friberg¹⁴, Roman Gold¹⁵, Mark A Gurwell⁹, Paul T P Ho⁸, Mareki Honma¹⁶, Makoto Inoue⁸, Michael Kosowsky¹⁷, Thomas P Krichbaum¹⁸, James Lamb¹⁹, Abraham Loeb⁹, Ru-Sen Lu²⁰, David MacMahon⁵, Jonathan C McKinney¹⁵, James M Moran⁹, Ramesh Narayan⁹, Rurik A Primiani⁹, Dimitrios Psaltis⁴, Alan E E Rogers², Katherine Rosenfeld⁹, Jason SooHoo², Remo P J Tilanus²¹, Michael Titus², Laura Vertatschitsch⁹, Jonathan Weintroub⁹, Melvyn Wright⁵, Ken H Young⁹, J Anton Zensus¹⁸, Lucy M Ziurys⁴

Affiliations

¹ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. mjohnson@cfa.harvard.edu.
² Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA.
³ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA.
⁴ Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA.
⁵ Department of Astronomy, Radio Astronomy Laboratory, 501 Campbell, University of California Berkeley, Berkeley, CA 94720-3411, USA.
⁶ Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911.
⁷ Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan. Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
⁸ Institute of Astronomy and Astrophysics, Academia Sinica, Post Office Box 23-141, Taipei 10617, Taiwan.
⁹ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
¹⁰ Academia Sinica Institute for Astronomy and Astrophysics (ASIAA), 645 N. A'ohōkū Pl. Hilo, HI 96720, USA.
¹¹ Department of Astrophysics/Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, Post Office Box 9010, 6500 GL Nijmegen, Netherlands.
¹² Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada. Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
¹³ Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748 Garching, Germany.
¹⁴ James Clerk Maxwell Telescope, East Asia Observatory, 660 N. A'ohōkū Place, University Park, Hilo, HI 96720, USA.
¹⁵ Department of Physics, Joint Space-Science Institute, University of Maryland at College Park, Physical Sciences Complex, College Park, MD 20742, USA.
¹⁶ National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan. Graduate University for Advanced Studies, Mitaka, 2-21-1 Osawa, Mitaka, Tokyo 181-8588.
¹⁷ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA. Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911.
¹⁸ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany.
¹⁹ Owens Valley Radio Observatory, California Institute of Technology, 100 Leighton Lane, Big Pine, CA 93513-0968, USA.
²⁰ Haystack Observatory, Route 40, Massachusetts Institute of Technology, Westford, MA 01886, USA. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany.
²¹ Department of Astrophysics/Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, Post Office Box 9010, 6500 GL Nijmegen, Netherlands. Leiden Observatory, Leiden University, Post Office Box 9513, 2300 RA Leiden, Netherlands.

PMID: 26785487
DOI: 10.1126/science.aac7087

Abstract

Near a black hole, differential rotation of a magnetized accretion disk is thought to produce an instability that amplifies weak magnetic fields, driving accretion and outflow. These magnetic fields would naturally give rise to the observed synchrotron emission in galaxy cores and to the formation of relativistic jets, but no observations to date have been able to resolve the expected horizon-scale magnetic-field structure. We report interferometric observations at 1.3-millimeter wavelength that spatially resolve the linearly polarized emission from the Galactic Center supermassive black hole, Sagittarius A*. We have found evidence for partially ordered magnetic fields near the event horizon, on scales of ~6 Schwarzschild radii, and we have detected and localized the intrahour variability associated with these fields.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.