estimation of s uper -massive black hole masses using spectro-polarometric observations

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)