Radiation pressure force and black hole mass determination in low-redshift type-i and type-II active galactic nuclei

Research output: Contribution to journalArticlepeer-review

Abstract

The distributions of L([O iii] λ5007), black hole (BH) mass and L/LEdd in two large samples of type-I and type-II active galactic nuclei (AGNs) are compared in order to test the suggestion that radiation pressure force is affecting the gas velocity in the broad line region and hence the BH mass determination. The samples are drawn from the Sloan Digital Sky Survey archive and are modified to represent the same parent distribution at 0.1 ≤ z ≤ 0.2. BH masses in type-I sources are calculated in two different ways, one using a simple virial mass assumption and the other by taking into account the effect of radiation pressure force on the gas. The simple virial-mass estimate results in good agreement with the σ-based BH mass and L/LEdd estimates in type-II sources. In contrast, there is a clear disagreement in the L/LEdd distributions when radiation pressure-based estimates are used. This indicates that radiation pressure force is not important in 0.1 ≤ z ≤ 0.2 AGNs with L5100= 1042.8-44.8 erg s-1. This has important implications to the physics of the gas producing the broad emission lines in AGNs, in particular the existence of extremely large column density (∼1024 cm-2) clouds.

Original languageEnglish
Pages (from-to)793-797
Number of pages5
JournalAstrophysical Journal
Volume695
Issue number1
DOIs
StatePublished - 10 Apr 2009

Keywords

  • Black hole physics
  • Emission lines
  • Galaxies: Active
  • Galaxies: nuclei
  • Quasars

Fingerprint

Dive into the research topics of 'Radiation pressure force and black hole mass determination in low-redshift type-i and type-II active galactic nuclei'. Together they form a unique fingerprint.

Cite this