Modeling polarization signatures of NIR radiation from the Sgr A* black hole environs

0384841 - ASÚ 2015 RIV GB eng C - Conference Paper (international conference)
Valencia-S, M. - Bursa, Michal - Karssen, G. - Dovčiak, Michal - Eckart, A. - Horák, Jiří - Karas, Vladimír
Modeling polarization signatures of NIR radiation from the Sgr A* black hole environs.
Astronomy at High Angular Resolution : The Central Kiloparsec in Galactic Nuclei. Bristol: Institute of Physics Publishing, 2012, 012073/1-012073/5. Journal of Physics Conference Series, 372. ISSN 1742-6588.
[Astronomy at High Angular Resolution - The Central Kiloparsec in Galactic Nuclei. Bad Honnef (DE), 28.08.2011-02.09.2011]
Grant - others:ESA(XE) ESA-PECS project No. 98040
Institutional research plan: CEZ:AV0Z10030501
Keywords : polarimetric light curves
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

The near-infrared (NIR) emission of Sagittarius A* (Sgr A*), the source associated with the supermassive black hole (4.4 x 10(6) M-circle dot) at the center of our galaxy, is polarized and highly variable. Correlations between intensity and polarimetric parameters of the observed light curves compared with the predicted ones for different configurations, allow us to extract information about the geometry of the radiating region. Here we present the theoretical polarimetric light curves expected in the case of optically thin NIR emission from overdense regions close to the marginal stable orbit. Using a numerical code we track the time evolution of detectable polarization properties produced by synchrotron emission of compact sources in the vicinity of the black hole. We show that the different setups lead to very distinctive patterns in the time profiles of polarized flux and the orientation of the polarization vector and as such may be used for determining the geometry of the accretion flow around Sgr A*.
Permanent Link: http://hdl.handle.net/11104/0214339