{% trans
"Lomonosov Moscow State University" %}
Sternberg Astronomical Institute
Ya. B. Zeldovich All-Moscow Seminar of Astrophysicists
Seminar 18 March 2016
| # | Reporters | Report title | Duration |
| 1 | Липунов В. М. (МГУ, ГАИШ МГУ) |
Новости | 10 min. |
| 2 | Титарчук Л. (University of Ferrara/Goddard Space Flight Center) |
Корреляция спектрального индекса рентгеновского излучения с темпом аккреции в двойных системах,содержащих нейтронную звезду или черную дыру. | 40 min. |
Корреляция спектрального индекса рентгеновского излучения с темпом аккреции в двойных системах,содержащих нейтронную звезду или черную дыру.
X-ray spectral index correlations vs mass accretion rate in neutron star and black hole X-ray binaries in their different spectral states. Theory vs observations
I present details of observations of neutron star (NS) and black hole (BH) binaries
and the first principle theory of X-ray spectral formation in neutron star (NS) and
black hole (BH) there. I show this model predicts the spectral index correlation
vs mass accretion rate as in the case of NS as well in the BH case.
In BHs the spectral index should increase and then saturate with mass accretion
rate because the index as an inverse of Comptonization parameter Y and Y-
parameter saturates with the high mass accretion in the converging flow onto BH.
Comparison of this model prediction with X-ray observations shows that in a
BH case the index, indeed, correlates and then saturates with mass accretion
rate. Moreover this index-mass accretion rate correlation allows us to estimate
BH masses and distance to the source. While in NS sources the observations
show that the index stays the same independently of spectral state of the source
which can be possible if the energy release in the disk is always much smaller of
that at NS TL (boundary layer).
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