Broad-line Balmer Decrements in Blue Active Galactic Nuclei

Abstract

We have investigated the broad-line Balmer decrements (Halpha/Hbeta) for a large, homogeneous sample of Seyfert 1 galaxies and QSOs using spectroscopic data obtained in the Sloan Digital Sky Survey. The sample, drawn from the Fourth Data Release, comprises 446 low redshift (z < 0.35) active galactic nuclei (AGN) that have blue optical continua as indicated by the spectral slopes in order to minimize the effect of dust extinction. We find that (i) the distribution of the intrinsic broad-line Halpha/Hbeta ratio can be well described by log-Gaussian, with a peak at Halpha/Hbeta=3.06 and a standard deviation of about 0.03 dex only; (ii) the Balmer decrement does not correlate with AGN properties such as luminosity, accretion rate, and continuum slope, etc.; (iii) on average, the Balmer decrements are found to be only slightly larger in radio-loud sources (3.37) and sources having double-peaked emission-line profiles (3.27) compared to the rest of the sample. We therefore suggest that the broad-line Halpha/Hbeta ratio can be used as a good indicator for dust extinction in the AGN broad-line region; this is especially true for radio-quiet AGN with regular emission-line profiles, which constitute the vast majority of the AGN population.

To appear in MNRAS. The data and the fitted parameters for the decomposed spectral components (continuum, FeII and other emission lines) of the 446 blue AGNs are available at http://staff.ustc.edu.cn/~xbdong/Data_Release/blueAGN_DR4/

References in corpus (37)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• Correcting for the Effects of Interstellar Extinction
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
• Determining Central Black Hole Masses in Distant Active Galaxies and Quasars. II. Improved Optical and UV Scaling Relationships
• The Fourth Data Release of the Sloan Digital Sky Survey
• Estimating Black Hole Masses in Active Galaxies Using the Halpha Emission Line
• The Relationship Between Luminosity and Broad-Line Region Size in Active Galactic Nuclei
• Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the M-sigma Relationship for AGNs
• Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys
• Black Hole Mass and Eddington Ratio as Drivers for the Observable Properties of Radio-Loud and Radio-Quiet QSOs
• Systematic Effects in Measurement of Black Hole Masses by Emission-Line Reverberation of Active Galactic Nuclei: Eddington Ratio and Inclination
• The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements
• Red and Reddened Quasars in the Sloan Digital Sky Survey
• The On-Orbit Performance of the Galaxy Evolution Explorer
• The FIRST Bright Quasar Survey. II. 60 Nights and 1200 Spectra Later
• A Comprehensive Study of 2 000 Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey: I. The Sample
• Locally Optimally Emitting Clouds and the Origin of Quasar Emission Lines
• The unusual emission line spectrum of IZw1
• Dust Reddening in SDSS Quasars
• Completion of a Survey and Detailed Study of Double-Peaked Emission Lines in Radio-Loud AGNs
• Double-Peaked Low-Ionization Emission Lines in Active Galactic Nuclei
• What the Optical Recombination Lines Can Tell Us About the Broad Line Regions of Active Galactic Nuclei
• Conference Summary: AGN Physics with the Sloan Digital Sky Survey
• The Nature of Radio-Intermediate Quasars: What is Radio-Loud and what is Radio-Quiet?
• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Early Data Release
• Is there a Dichotomy in the Radio Loudness Distribution of Quasars?
• On the origin of the C IV Baldwin effect in AGN
• A Large, Uniform Sample of X-ray Emitting AGN from the ROSAT All-Sky and Sloan Digital Sky Surveys: the Data Release 5 Sample
• Profile variability of the H-alpha and H-beta broad emission lines in NGC5548
• Partially obscured quasars in the Sloan Digital Sky Survey Early Data Release
• The Optical-UV Continuum of a Sample of QSOs
• The UV Properties of SDSS Selected Quasars
• A search for signatures of quasar evolution: Comparison of the shapes of the rest-frame optical/UV continua of quasars at z>3 and z~0.1
• The "red shelf" of the Hb line in the Seyfert 1 galaxies RXS J01177+3637 and HS 0328+05

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