On the Virialization of Disk Winds: Implications for the Black Hole Mass Estimates in AGN

Abstract

Estimating the mass of a supermassive black hole (SMBH) in an active galactic nucleus (AGN) usually relies on the assumption that the broad line region (BLR) is virialized. However, this assumption seems invalid in BLR models that consists of an accretion disk and its wind. The disk is likely Keplerian and therefore virialized. However, the wind material must, beyond a certain point, be dominated by an outward force that is stronger than gravity. Here, we analyze hydrodynamic simulations of four different disk winds: an isothermal wind, a thermal wind from an X-ray heated disk, and two line-driven winds, one with and the other without X-ray heating and cooling. For each model, we check whether gravity governs the flow properties, by computing and analyzing the volume-integrated quantities that appear in the virial theorem: internal, kinetic, and gravitational energies, We find that in the first two models, the winds are non-virialized whereas the two line-driven disk winds are virialized up to a relatively large distance. The line-driven winds are virialized because they accelerate slowly so that the rotational velocity is dominant and the wind base is very dense. For the two virialized winds, the so-called projected virial factor scales with inclination angle as $1/{\sin }^{2}i$. Finally, we demonstrate that an outflow from a Keplerian disk becomes unvirialized more slowly when it conserves the gas specific angular momentum -- as in the models considered here, than when it conserves the angular velocity -- as in the so-called magneto-centrifugal winds.

Accepted to ApJ

References in corpus (5)

• The effect of radiation pressure on virial black hole mass estimates and the case of Narrow Line Seyfert 1 galaxies
• Stellar Velocity Dispersion Measurements in High-Luminosity Quasar Hosts and Implications for the AGN Black Hole Mass Scale
• The Lick AGN Monitoring Project 2011: Fe II Reverberation from the Outer Broad-Line Region
• On the geometry of broad emission region in quasars
• Revisiting the Black Hole Masses of Soft X-ray-Selected Active Galactic Nuclei

Cited by in corpus (17)

• A global view of the inner accretion and ejection flow around super massive black holes: radiation driven accretion disk winds in a physical context
• Line-driven Disk Winds in Active Galactic Nuclei: The Critical Importance of Ionization and Radiative Transfer
• Self-shadowing Effects of Slim Accretion Disks in Active Galactic Nuclei: Diverse Appearance of the Broad-line Region
• Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. VIII. Structure of the Broad-Line Region and Mass of the Central Black Hole in Mrk 142
• Failed radiatively Accelerated Dusty Outflow model of the Broad Line Region in Active Galactic Nuclei. I. Analytical solution
• The Complete Ultraviolet Spectrum of the Archetypal "Wind-Dominated" Quasar Mrk~231: Absorption and Emission from a High-Speed Dusty Nuclear Outflow
• Reverberation Mapping of the Broad Line Region: application to a hydrodynamical line-driven disk wind solution
• Mass Outflow of the X-ray Emission Line Gas in NGC 4151
• The reverberation signatures of rotating disc winds in active galactic nuclei
• Near Infrared Spectra and Intrinsic Luminosities of Candidate Type II Quasars at 2 < z < 3.4
• Black Hole Mass Estimation: How good is the virial estimate?
• AGN STORM 2: II. Ultraviolet Observations of Mrk817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope
• Using the Properties of Broad Absorption Line Quasars to Illuminate Quasar Structure
• Radiative non-isothermal Bondi accretion onto a massive black hole
• On The Fine Tuning and Physical Origin of Line-Locked Absorption Systems in Active Galaxies
• AGN STORM 2: I. First results: A Change in the Weather of Mrk 817
• Leaked Lya emission: an indicator of the size of quasar absorption outflows