Disc and wind in black hole X-ray binary MAXI J1820+070 observed through polarized light during its 2018 outburst
Autor: | Juri Poutanen, Ilia A. Kosenkov, Masato Kagitani, Svetlana V. Berdyugina, Takeshi Sakanoi, Vadim Kravtsov, Andrei Berdyugin, Alexandra Veledina, Vilppu Piirola |
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Rok vydání: | 2020 |
Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics 010308 nuclear & particles physics Scattering Astrophysics::High Energy Astrophysical Phenomena Polarimetry X-ray binary FOS: Physical sciences Astronomy and Astrophysics Optical polarization Astrophysics Radiation Polarization (waves) Position angle 01 natural sciences 13. Climate action Space and Planetary Science 0103 physical sciences Radiative transfer Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics |
Zdroj: | Monthly Notices of the Royal Astronomical Society: Letters. 496:L96-L100 |
ISSN: | 1745-3933 1745-3925 |
DOI: | 10.1093/mnrasl/slaa096 |
Popis: | We describe the first complete polarimetric dataset of the entire outburst of a low-mass black hole X-ray binary system and discuss the constraints for geometry and radiative mechanisms it imposes. During the decaying hard state, when the optical flux is dominated by the non-thermal component, the observed polarization is consistent with the interstellar values in all filters. During the soft state, the intrinsic polarization of the source is small, $\sim 0.15$ per cent in $B$ and $V$ filters, and is likely produced in the irradiated disc. A much higher polarization, reaching $\sim 0.5$ per cent in $V$ and $R$ filters, at position angle of $\sim 25^\circ$ observed in the rising hard state coincides in time with the detection of winds in the system. This angle coincides with the position angle of the jet. The detected optical polarization is best explained by scattering of the non-thermal (hot flow or jet base) radiation in an equatorial wind. Comment: 5 pages, 2 figures, 1 table. Accepted to MNRAS Letters |
Databáze: | OpenAIRE |
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