Intervening BLR Clouds' Effects on Optical/UV Spectrum

Abstract

Recent x-ray observations of Mrk 766 suggest that broad emission line region clouds cross our line of sight and produce variable x-ray absorption. Here we investigate what optical/ultraviolet spectroscopic features would be produced by such "Intervening BLR Clouds" (IBC) crossing our line of sight to the accretion disk, the source of the optical/UV continuum. Although the emission spectrum produced by intervening clouds is identical to the standard BLR model, they may produce absorption features on the optical or UV continuum. Single clouds will have little effect on the optical/UV spectrum because BLR clouds are likely to be much smaller than the accretion disk. This is unlike the X-ray case, where the radiation source is considerably smaller. However, an ensemble of intervening clouds will produce spectroscopic features in the FUV including a strong depression between the Lyman limit and Lyα. The amount of the depression will indicate the line-of-sight covering factor of clouds, an unknown quantity that is important for the ionization of the intergalactic medium and the energy budget of AGN. Comparison with observations suggests that the SED of Mrk 766 may be affected by intervening BLR clouds and IBC may exist in most of AGNs.

22 pages, 11 figures

References in corpus (27)

• The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta
• Locally Optimally Emitting Clouds and the Origin of Quasar Emission Lines
• Extreme X-ray spectral variability in the Seyfert 2 Galaxy NGC 1365
• Occultation measurement of the size of the X-ray emitting region in the Active Galactic Nucleus of NGC 1365
• CAIRNS: The Cluster And Infall Region Nearby Survey I. Redshifts and Mass Profiles
• An Atlas of Computed Equivalent Widths of Quasar Broad Emission Lines
• What broad emission lines tell us about how active galactic nuclei work
• Seyferts on the edge: polar scattering and orientation-dependent polarization in Seyfert 1 nuclei
• X-ray absorption by Broad Line Region Clouds in Mrk 766
• An Unveiling Event in the Type 2 AGN NGC4388: A Challenge for a Parsec Scale Absorber
• Quasars and the Big Blue Bump
• A Systematic Analysis of Fe II Emission in Quasars: Evidence for Inflow to the Central Black Hole
• The power output of local obscured and unobscured AGN: crossing the absorption barrier with Swift/BAT and IRAS
• Conference Summary: AGN Physics with the Sloan Digital Sky Survey
• Rapid N_H changes in NGC 4151
• AGN Obscuration and the Unified Model
• How complex is the obscuration in AGN? New clues from the Suzaku monitoring of the X-ray absorbers in NGC7582
• The XMM-Newton long look of NGC 1365: uncovering of the obscured X-ray source
• Hbeta Profiles in Quasars: Evidence for an Intermediate-line Region
• Are AGN Broad Emission Lines Formed by Discrete Clouds? --- Analysis of Keck High Resolution Spectroscopy of NGC 4151
• Do the Broad Emission Line Clouds See the Same Continuum that We See?
• Star formation in self-gravitating disks in active galactic nuclei. I. Metallicity gradients in broad line regions
• A Survey of Intrinsic Absorption in Active Galaxies using the Far Ultraviolet Spectroscopic Explorer
• Star formation in self-gravitating disks in active galactic nuclei. II. Episodic formation of broad line regions
• Accretion Disks in Active Galactic Nuclei: Gas Supply Driven by Star Formation
• Compton-thick active galactic nuclei inside local ultraluminous infrared galaxies
• Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+64

Cited by in corpus (5)

• Probing the circumnuclear absorbing medium of the buried AGN in NGC 1068 through NuSTAR observations
• The Dusty Heart of NGC 4151 Revealed by $\lambda \sim$1-40 $\mu$m Reverberation Mapping and Variability: A Challenge to Current Clumpy Torus Models
• Constraining UV Continuum Slopes of Active Galactic Nuclei With CLOUDY Models of Broad Line Region EUV Emission Lines
• Broad-line Region Clouds orbiting an AGN sample
• Space Telescope and Optical Reverberation Mapping Project. XIII. An Atlas of UV and X-ray Spectroscopic Signatures of theDisk Wind in NGC 5548