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OPTICAL SPECTRAL VARIABILITY OF QUASAR E1821+643

Study of the optical spectral variability of quasar E1821+643, including the variability of broad line fluxes and continuum, line profile variations, and estimating the mass of the supermassive black hole.

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OPTICAL SPECTRAL VARIABILITY OF QUASAR E1821+643

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  1. OPTICAL SPECTRAL VARIABILITY OF QUASAR E1821+643 Dragana Ilić, Luka Č. Popović, Alla I. Shapovalova, V.H. Chavushyan, A. Burenkov, W. Kollatschny, A. Kovačević University of Belgrade, Special Astrophysical Observatory Russia Astronomical Observatory Belgrade, University of Goettingen, INAOE Mexico

  2. AGN: Broad Line Region Zheng et al. 1997 • we cannot resolve with current optical telescopes center of these objects spectroscopy is an important tool • Some open questions: • Co-evolution of host galaxy and supermassive black hole -> M-σ relation (review Ferrarese & Ford) • Mass of supermassive black holes in AGN (review Ilic & Popovic 2014) • Mergers of galaxies -> binary AGN (review Popovic 2012) 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  3. AGN: variable objects in optical NGC 5548 (Peterson et al. 2002) minimum activity maximum activity 3c390.3 (Shapovalova et al. 2010) 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs • line flux and continuum variations • line profile variations

  4. Mass of SMBH & Broad Lines • We need: • optical emission lines • properties of the Broad Line Region - BLR Virial theorem (Wandel+ 1999; Kaspi+ 2000, 2005; Peterson+ 2004, Onken+ 2004, Bentz+ 2009) EMPIRICAL RELATION CAN GET MBH FROM SINGLE EPOCH OBSERVATIONS RBLR = a × (L5100) γpc • L5100 : continuum luminosity (λLλ) at 5100 A • γ= 0.6 ± 0.1 (e.g. Bentz et al. 2009) • a: constant, depends on used line 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  5. To estimate MBH we need geometry and physics of BLR What do weknow about BLR? • many assumptions, e.g. gas photoionizedby the accretion disk continuum • parameter f: geometry of BLR not known • FWHM  up to 10,000 km/s • complex region • geometry: ? • disk / outflows / disk+wind / disk+spherical region??? • T  104 KNe ~ 1010-12? cm-3 • photoionized region • (or shock heating?)

  6. Long-term monitoring of AGN • PIs: Alla I. Shapovalova (Russia) Vahram H. Chavushyan (Mexico) • constantly observing well known AGN with broad emission lines: • NGC 5548 – 9+ years (Shapovalova+ 2004, Ilić 2007, Popović+2008, Bon+ 2016 submitted, Rakić+ 2016 submitted) • NGC 4151 – 11+ years (Shapovalova+ 2008, 2009, 2010a, Ilić+2010, Bon+ 2012) • 3C390.3 – 13 years (Shapovalova+ 2001, Shapovalova+ 2010b, Popović+ 2011, Jovanović+ 2010, Kovačević+ 2014) • Ark 564 – 11 years (Shapovalova+ 2011, Shapovalova+ 2012) • Arp 102B – 12 years (Shapovalova+2013, Popović+ 2014, Kovačević+ 2014) • E1821+643 – 25 years (Shapovalova+2016, Ilic+2016 in prep.) 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  7. Observations 6m + 1m telescopes - SAO RAS (Russia) 2.1m telescope - Guillermo Haro Observatory, Cananea, Sonora,Mexico 2.1mtelescope - Observatorio Astronómico Nacional, San PedroMartir, Baja California, Mexico 3.5m + 2.2m telescopes – Calar Alto Observatory, Spain 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  8. Quasar E1821+643 • the most luminous, radio-quiet quasars in the local universe (z = 0.297, MV=−27.1) • models of strong optical/UV “blue bump” gives SMBH mass of 3×109Msun, accretion rate of 19 Msun yr−1 (Kolman et al. 1993) • resides in a large elliptical galaxy, associated with the rich cluster of galaxies (Hutchings & Neff 1991) • interesting broad line profiles: • highly red asymmetric profiles • redshifted (≈1000 km/s) • we did: first long-term spectral optical monitoring 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  9. E1821+643 • Shapovalova +, 2016, ApJS light curves 1990 - 2014 CCFs give lags of ~120ld giving MBH=2.6×109Msun 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  10. Getting the Broad Line Profiles monthly-averaged broad lines → gaussian fitting developed by our group (see. e.g. Popovic+2004) red wing extending to Doppler velocities of at least ∼15,000 km/s 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  11. Mean & rms profiles of Hβ and Hγ Mean and RMS compared Both profiles normalized to unity • Shapovalova +, 2016 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  12. Mean Hβ vs. Hγ profile • the mean Hβ has a more extensive red wing than does the mean Hγ • an additional emission in the far wing of the mean Hβ • the difference has: • shift~ 7100 km/s • FWHM ~5800 km/s 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  13. Blue peak shift of broad Hβ • Phase curve of the Plavchan algorithm: ~4700-day period • same in spectro-photometry (talk of Andjelka) red asymmetry, broad line peak redshifted between ∼700 and 1600 km/s Light curve of blue peak 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  14. Conclusions for E1821+643 moderately variable broad line fluxes and continuum  CCFs give size of the BLR of ~120 ld MBH=2.6×109Msun (consistent with previous results) broad line profile NOT varying during 25 years extremely asymmetric, red wing up to ∼15000 km/s broad Hβ peak redshifted for +1000 km s−1 hard to explain binary black hole hypothesis with one BLR – since broad lines shift always in the red wing more likely: dense, gas-rich, cloudy-like structures orbiting around a recoiling black hole 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  15. Thank you for your attention! Part of thiswork supported by 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

  16. Blue part of the spectra: fittings Balmer pseudocontinuum: Balmer continuum + high order Balmer lines (template fit taken from Kovacevic+ 2014) Ilic+ 2016, in prep 10th SCSLSA: Dragana Ilić dilic@matf.bg.ac.rs

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