2008/02/25 by Lei Huang, L. Huang, S. Liu +9
Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Linear polarization #Magnetic field #Magnetohydrodynamics #Magnetorotational instability #Milky Way #Millimeter #Optics #Physics #Polarization (electrochemistry) #Sagittarius #Stars #Synchrotron radiation #Torus #astro-ph
paper · pdf · doi:10.1086/587742
12 pages, 2 figures, ApJL accepted
arxiv created 2008/02/25 · openalex publication_date 2008/03/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We perform general relativistic ray-tracing calculations of the transfer of polarized synchrotron radiation through the relativistic accretion flow in Sagittarius (Sgr) A*. Based on a two-temperature magnetorotational instability (MRI) induced accretion mode, the birefringence effects are treated self-consistently. By fitting the spectrum and polarization of Sgr A* from millimeter to near-infrared bands, we are able to not only constrain the basic parameters related to the MRI and the electron heating rate, but also limit the orientation of the accretion torus. These constraints lead to unique polarimetric images, which may be compared with future millimeter and submillimeter VLBI observations. In combination with general relativistic MHD simulations, the model has the potential to test the MRI with observations of Sgr A*.