2004/11/23 by J. E. G. Peek, Joshua E. Goldston, Eliot Quataert +2
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/427741
published as Astrophys.J. 621 (2005) 785-792 · Accepted for publication in ApJ
arxiv created 2004/11/23 · openalex publication_date 2005/03/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We calculate synchrotron radiation in three-dimensional pseudo-Newtonian magnetohydrodynamic simulations of radiatively inefficient accretion flows. We show that the emission is highly variable at optically thin frequencies, with order-of-magnitude variability on timescales as short as the orbital period near the last stable orbit; this emission is linearly polarized at the ~20%-50% level because of the coherent toroidal magnetic field in the flow. At optically thick frequencies, both the variability amplitude and polarization fraction decrease significantly with decreasing photon frequency. We argue that these results are broadly consistent with the observed properties of Sgr A* at the Galactic center, including the rapid infrared flaring.