Resolved Magnetic-Field Structure and Variability Near the Event Horizon of Sagittarius A*
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 fields near the event horizon, on scales of ~6 Schwarzschild radii, and we have detected and localized the intra-hour variability associated with these fields.
Keywords
Cite
@article{arxiv.1512.01220,
title = {Resolved Magnetic-Field Structure and Variability Near the Event Horizon of Sagittarius A*},
author = {Michael D. Johnson and Vincent L. Fish and Sheperd S. Doeleman and Daniel P. Marrone and Richard L. Plambeck and John F. C. Wardle and Kazunori Akiyama and Keiichi Asada and Christopher Beaudoin and Lindy Blackburn and Ray Blundell and Geoffrey C. Bower and Christiaan Brinkerink and Avery E. Broderick and Roger Cappallo and Andrew A. Chael and Geoffrey B. Crew and Jason Dexter and Matt Dexter and Robert Freund and Per Friberg and Roman Gold and Mark A. Gurwell and Paul T. P. Ho and Mareki Honma and Makoto Inoue and Michael Kosowsky and Thomas P. Krichbaum and James Lamb and Abraham Loeb and Ru-Sen Lu and David MacMahon and Jonathan C. McKinney and James M. Moran and Ramesh Narayan and Rurik A. Primiani and Dimitrios Psaltis and Alan E. E. Rogers and Katherine Rosenfeld and Jason SooHoo and Remo P. J. Tilanus and Michael Titus and Laura Vertatschitsch and Jonathan Weintroub and Melvyn Wright and Ken H. Young and J. Anton Zensus and Lucy M. Ziurys},
journal= {arXiv preprint arXiv:1512.01220},
year = {2015}
}
Comments
Accepted for publication in Science; includes Supplementary material