Polarization properties of bow shock sources close to the Galactic centre

0484969 - ASÚ 2018 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Zajaček, M. - Karas, Vladimír - Hosseini, E. - Eckart, A. - Shahzamanian, B. - Valencia-S, M. - Peissker, F. - Busch, G. - Britzen, S. - Zensus, J. A.
Polarization properties of bow shock sources close to the Galactic centre.
Proceedings of RAGtime 17/19: Workshops on black holes and neutron stars. Opava: Silesian University, 2017, s. 237-252. Publications of the Institute of Physics, 8. ISBN 9788075102577. ISSN 2336-5668.
[RAGtime /17.-19./. Opava (CZ), 17.11.2015-19.11.2015]
Grant CEP: GA MŠMT LTI17018; GA MŠMT(CZ) 7E13012
GRANT EU: European Commission(XE) 312789 - STRONGGRAVITY
Institucionální podpora: RVO:67985815
Klíčová slova: black hole physics – Galaxy: centre – * galaxy centra * radiative transfer
Obor OECD: Astronomy (including astrophysics,space science)
http://proceedings.physics.cz/images/proc17/zaj.pdf

Several bow shock sources were detected and resolved in the innermost parsec from the supermassive black hole in the Galactic centre. They show several distinct characteristics, including an excess towards mid-infrared wavelengths and a significant linear polarization as well as a characteristic prolonged bow-shock shape. These features give hints about the presence of a non-spherical dusty envelope generated
by the bow shock. The Dusty S-cluster Object (also denoted as G2) shows similar characteristics and it is a candidate for the closest bow shock with a detected proper motion in the vicinity of Sgr A*, with the pericentre distance of only approx. 2000 Schwarzschild radii. However, in the continuum emission it is a point-like source and hence we use Monte Carlo radiative transfer modeling to reveal its possible three-dimensional structure. Alongside the spectral energy distribution, the detection of polarized continuum emission in the near-infrared Ks-band (2.2 micrometers) puts additional constraints on the geometry of the source.
Trvalý link: http://hdl.handle.net/11104/0280091