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L. Č. Popović V. Afanasiev, A. Shapovalova Astronomical Observatory Belgrade, Serbia Special Astrophysical Observatory, Russia. Estimation of s uper -massive black hole masses using spectro-polarometric observations. AGN - strucutre. - PowerPoint PPT Presentation
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L. Č. PopovićV. Afanasiev, A. Shapovalova
Astronomical Observatory Belgrade, SerbiaSpecial Astrophysical Observatory, Russia
Super-massive black hole in the center (1E7-1E9 solar masses)
accretion disc – emitting X, UV but also optical emission
Broad Line Region – around the compact disc (disc like?), close to the BH, line emission about several 1000 km/s
Narrow Line Region – at big distance from BH, emission lines up to 1000 km/s
Torus – near alaigned with the AD, neutral gas, contribute to the IR emission
Jets – outflowing matterial, direction perpendicular to the AD
MBH = f * rBLRFWHM2/G rBLR = a * (L5100) γ pc where L5100 is the continuum luminosity
(λLλ) at 5100 A in 1046 erg s−1
and γ˚= 0.6 ± 0.1, constant a depends on the line in question. For Hβ, a ≃ 0.4 pc (e,g, Bentz et al. 2009)
BLR
GEO
METR
Y
BLR
D
IMEN
SIO
NS
BLR
KIN
EM
ATIC
S
Geometry can be very complex (e.g. disk+smt. see e.g. Popovic+2004; Bon et al. 2009 MNRAS 400, 924). The role of the torus
Monitoring programs (see e.g. Shapovalova+, Popovic+ 2008-2014) – reverberation mapping
Depends also on geometry – two component broad line region
Other lines in the field of broad lines, as e.g. Fe II lines
Estimate kinematics (measuring line widths)
Mrk 6 – see Afanasiev+
2014
Polar scattering region (optically thin gas & dust)
i ~ 0, scattering ~ 0 (E ), direct view of accretion disk (E ) and jet (E )
Dusty torus, size~ 1018cm
BLR, size~1017cm
Accretion disk size~ 1015cm
BH, M~108M . Rg~1013cm
Equatorial scattering region (two-component matter BLR)
Jet
viewing angle, i
Ionization cone i <45, equatorial scattering > 0, (E )
i ~ 90, polar scattering > 0 (E), visibility BLR in polarized light
BL Lac, RG, radio-loud QSO,
UV-polarization in cone ionization
Sy1, radio-lobe QSO , Bal QSO
Sy2,
comparison of polarization in the continuum and lines, both for NLR and BLR (to check the unified model)
search for the broad lines in polarized light in Sy2
dependence of the polarization on redshift ( L-forest )
polarization variability - jet and outflows, nonhomogeneous
BLR, instability in an accretion disk (AD)
dependence of the continuum polarization on wavelength –
mechanisms of scattering, estimation of magnetic field in AD.
Black hole mass estimates?
Broad line shapes
Broad line P.A.
Sketch showing a possible far-field scattering geometry in which Hα photons from BLR clouds undergoing bi-polar outflow are scattered by dust or free electrons in the inner wall of a
surrounding torus.
Corbett E A et al. MNRAS 2000;319:685-699
Equatorial polarization – Keplerian disk – polarization in the broad line
V1 v2 v3
V1
v2
v3
Velocity in line
torus
P.A
,
To the observer
-0.5
Rsc ~ 0.18 pc ~ 220 light days (Kishimoto et al. 2011)
8,,
1
Estimation of Rsc or Rmax
The inner radius of the Torus
or connecting rev. R with max disc dimensions
Estimates from observations
-Torus – equatorial polarization- two additional polarization components probably polar polarization (outflows).
-P.A. in the broad lines - evidence for the Keplerian motion-Estimation of the mass of the black (Afanasiev et al. 2014)-.
-Using spectro-polarimetric observations we estimated the black hole mas of Mrk 6 as 1.16 × 1E∼ 8 8 M⊙, that is a low limit of mass. However our estimate is in a good agreement with ones obtained by reverberation (MBH 1.3 − 1.8 × ∼1E8 M ). ⊙-- some problems in BH mass estimates –ISM, different source of polarization, estimates of Rsc or Rmax of the disk
-
Thank you for your attention!
Pol. cont. and broad line lags ~2 and 23
l.d
- Mrk 6 (IC 450) is a Seyfert 1.5 galaxy (z=0.0185, m(B)=14.29, M(B)=-20.41
- Spectropolarimetric observations (monitoring) of Mrk 6 AGN with the 6-m BTA Telescope in more than two years period, from 2010 to 2013 (12 spectra)
- spectral range - covering Hα and Hβ lines - -estimation of the ISM polarization – very
important (details in Afanasiev et al. 2013, arXiv1310.1179, paper sent to MNRAS)