Black Holes in Binary Systems and Galaxy Nuclei. A.M Cherepashchuk Lomonosov Moscow State University, Sternberg Astronomical Institute. Overview:. Introduction: 40 years of BHs investigations. Observations of stellar mass BHs in X-ray binary systems. Stellar mass BH demography.
Lomonosov Moscow State University,
Sternberg Astronomical Institute
A big dream of Ya.B.Zeldovich was to discover a real black holes in the Universe.
M star < 3M => NS or WD.
According to modern theory of stellar evolution taking into account Einstein General Relativity, if:
for non-rotating (Schwarzschild) BH,
for rotating BH.
rg = 9 mm for the Earth, rg = 3 km for the Sun,
rg = 40 AU for MBH = 2·109 M
R. Giacconi – Nobel Prize (2002)
Theoretical prediction of X-ray from accreting BH:
Giacconi et al. (1972) – UHURU epoch.
~100 compact X-ray sources, most of which are X-ray binaries.
First X-ray binaries: Cyg X-1, Her X-1, Cen X-3, Vela X-1, SMC X-1, etc.
Cherepashchuk, Efremov, Kurochkin, Shakura, Sunyaev, 1972,
J. Bahcall, N. Bahcall, 1972,
Lyutyi, Sunyanev, Cherepashchuk, 1973
Dt ≈ 10-3 s,
r ≤ cDt ≈ 300 km = 10 rg.
Narayan and McClintock, 2012
Direct observations of the motion of the “probe bodies” in the gravitational field of BH (stars, gaseous disks etc.).
Gillessenet al., 2009
Observations of time delay Dt between variability of emission lines and continuum in galactic nucleus (Cherepashchuk and Lyutyi, 1973).
r ≈ c· Dt.
v – from the width of emission line profile
(e.d. Kormendy and Ho, 2013).
a*=0.998-0.40 (e.d. Gnedin et al., 2012).
Up to now more than dozen of bright quasars (MBH ≈ 108 – 109 M ) with high redshifts
z = 6 – 8
have been discovered.
Therefore the characteristic growing time for the mass of supermassive BHs is less then 109 years.
MBH ~ M buldge (MBH = 0.001 Mbuldge)
MBH ~ σbuldge (α ≈ 4 – 5)
There is correlation between MBH and Mbuldge, MBH and σbuldge (velocity dispersion of stars in the buldge):
Some correlation between MBH and asymptotic rotational velocity of galaxy VFAR has been suspected (Ferrarese, 2002; Baes et al., 2003).
Full mass of the galaxy is determined by VFAR: baryonic matter (~10%) and dark matter (~90%).
Deep cusps are formed in the protogalactic clouds (consisting basically of dark matter) during their evolution due to gravitational instability.
(Cherepashchuk, Afanasiev, Zasov, Katkov, 2010)
of SAO RAS
MBH are determined by resolved kinematics and reverberation mapping methods.
- BHs, - nuclear clusters,
See, for example, results of computer simulations:
Xu et al., 2007
Cook et al., 2009
A big progress in observations of stellar mass BHs and supermassive BHs has been achieved during last 40 years. Hundreds of reliable BH candidates have been discovered up to now.
All observational appearances of BH candidates are in excellent agreement with Einstein General Relativity.
Taking into account observational selection effects we can estimate the full number of stellar mass BHs in our Galaxy as ~107. For the mean mass MBH ≈ 9 – 10 M it is ~ 108 M or 0.1% of the baryonic mass in our Galaxy.
VLBI and Space interferometers, e.g. Event Horizon Telescope, MILLIMETRON.
In the case of rapidly rotating inner disk flux distribution around BH is asymmetric due to the disk rotation (Doppler effect) and the frame-dragging effects. The shape of the shadow casted by the BH is asymmetric due to the frame-dragging effects around the rotating black hole (Takahashi & Watarai 2007).
Recent VLBI observations of Sgr A* at = 1.3 mm (Doeleman et al. 2008) obtained a size of microarcseconds for the intrinsic diameter of Sgr A*.
This is less than the expected apparent size of the event horizon (~ 52 microarcseconds) of the presumed BH. It can be suggested that the bulk of Sgr A* emission may not be centered on the BH, but arises in the surrounding accretion flow or outflowing jet.
Millimetron observations will open a new window onto fundamental black hole physics.