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

1. L. Č. Popović V. Afanasiev, A. Shapovalova Astronomical Observatory Belgrade, Serbia Special Astrophysical Observatory, Russia Estimation of super-massive black hole masses using spectro-polarometric observations

2. AGN - strucutre • 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

3. AGN – structure - emission regions and black hole mass estimates

4. Mass of SMBH & broad Lines BLR KINEMATICS BLR GEOMETRY BLR DIMENSIONS • 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)

5. PROBLEMS - geometry • 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

6. PROBLEMS - size of the BLR • 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

7. PROBLEMS – kinematics • Estimate kinematics (measuring line widths)

8. Can polarization in the broad line help? • Mrk 6 – • see Afanasiev+ 2014

9. Structure and expected polarization in AGN i~ 0, scattering ~ 0 (E ), direct view of accretion disk(E ) and jet (E ) BL Lac, RG, radio-loud QSO, UV-polarization in cone ionization i<45, equatorial scattering>0, (E ) Ionization cone Sy1, radio-lobe QSO , Bal QSO Polar scattering region (optically thin gas & dust) viewing angle, i Equatorial scattering region (two-component matter BLR) Jet i~ 90, polar scattering> 0 (E), visibilityBLR inpolarized light Dusty torus, size~ 1018cm Sy2, BH, M~108M . Rg~1013cm BLR, size~1017cm Accretion disk size~ 1015cm

10. AGN polarization: Observational aims in the optical range • comparison of polarizationin 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?

11. Equatorial polarization:Smith et al. 2004,2005 Broad line P.A. Broad line shapes

12. Equatorial polarization – Keplerian disk – polarization in the broad line 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

13. Equatorial polarization – Keplerian disk – polarization in the broad line V1 v2 v3 V1 v2 v3

14. Equatorial scattering in Mrk 6 P.A, To the observer Velocity in line torus

15. Keplerian motion in the Mrk 6 BLR – Afanasiev et al. 2014

16. V vs. tan(phi) – direct evidence of Keplerian motion in the BLR of Mrk 6 -0.5

17. New method for the BH mass estimation (Afanasiev et al. 2014) 1 Rsc ~ 0.18 pc ~ 220 light days(Kishimoto et al. 2011) 8 Reverebaration 1.3-1.8 x10 M ,,

18. Problems –estimates of Rsc • Estimation of Rsc or Rmax • The inner radius of the Torus • or connecting rev. R with max disc dimensions • Estimates from observations

19. Problems: Polarization in lines -different sourcesof polarization(Mrk 6, Afanasiev+2014

20. Three regions of scatter • Torus – equatorial polarization • two additional polarization components probably polar polarization (outflows).

21. Problems: ISM polarization can affect P.A. vs V

22. Conclusions: • 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 × 1E8 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!

24. Results: variability Pol. cont. and broad line lags ~2 and 23 l.d

25. Polarization incontinuum:disc - jet

26. Observations

27. Polarization and mass of super-massive black holes: The case of Mrk 6 - Mrk 6 (IC 450) is a Seyfert 1.5 galaxy (z=0.0185, m(B)=14.29, M(B)=-20.41 - Spectropolarimetric observations (monitoring)ofMrk 6AGN 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)