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Author
dc.contributor.author
Yip, CW 
Author
dc.contributor.author
Connolly, AJ 
Author
dc.contributor.author
Berk, DEV 
Author
dc.contributor.author
Scranton, R 
Author
dc.contributor.author
Krughoff, S 
Author
dc.contributor.author
Szalay, AS 
Author
dc.contributor.author
Dobos, L 
Author
dc.contributor.author
Tremonti, C 
Author
dc.contributor.author
Taghizadeh-Popp, M 
Author
dc.contributor.author
Budavari, T 
Availability Date
dc.date.accessioned
2020-08-11T08:24:31Z
Availability Date
dc.date.available
2020-08-11T08:24:31Z
Release
dc.date.issued
2009
uri
dc.identifier.uri
http://hdl.handle.net/10831/47803
Abstract
dc.description.abstract
Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broadline (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type 2 AGNs to be composed mainly of stellar light and nonvariable on the timescales of months to years. In this work we probe the spectroscopic variability of galaxies and narrow-line AGNs using the multiepoch data in the Sloan Digital Sky Survey Data Release 6. The sample contains 18,435 sources for which there exist pairs of spectroscopic observations (with a maximum separation in time of similar to 700 days) covering a wavelength range of 3900-8900 angstrom. To obtain a reliable repeatability measurement between each spectral pair, we consider a number of techniques for spectrophotometric calibration resulting in an improved spectrophotometric calibration of a factor of 2. From these data we find no obvious continuum and emission-line variability in the narrow-line AGNs on average-the spectroscopic variability of the continuum is 0.07 +/- 0.26 mag in the g band and, for the emission-line ratios log(10)([N II]/H alpha) and log(10)([O III]/H beta), the variability is 0.02 +/- 0.03 dex and 0.06 +/- 0.08 dex, respectively. From the continuum variability measurement we set an upper limit on the ratio between the flux of the varying spectral component, presumably related to AGN activities, and that of the host galaxy to be similar to 30%. We provide the corresponding upper limits for other spectral classes, including those from the BPT diagram, eClass galaxy classification, stars, and quasars.
Language
dc.language
Angol
Title
dc.title
PROBING SPECTROSCOPIC VARIABILITY OF GALAXIES AND NARROW-LINE ACTIVE GALACTIC NUCLEI IN THE SLOAN DIGITAL SKY SURVEY
Type
dc.type
folyóiratcikk
Date Change
dc.date.updated
2020-05-13T16:14:09Z
Scope
dc.format.page
5120-5133
Doi ID
dc.identifier.doi
10.1088/0004-6256/137/6/5120
Wos ID
dc.identifier.wos
000266662300049
ID Scopus
dc.identifier.scopus
84882938830
MTMT ID
dc.identifier.mtmt
1325434
Issue Number
dc.identifier.issue
6
abbreviated journal
dc.identifier.jabbrev
ASTRON J
Journal
dc.identifier.jtitle
ASTRONOMICAL JOURNAL
Volume Number
dc.identifier.volume
137
Release Date
dc.description.issuedate
2009
department of Author
dc.contributor.institution
Alba Regia Egyetemi Központ
department of Author
dc.contributor.institution
Fizika Doktori Iskola
department of Author
dc.contributor.institution
Fizikai Intézet
department of Author
dc.contributor.institution
Mérnöki Intézet
department of Author
dc.contributor.institution
Komplex Rendszerek Fizikája Tanszék
Author institution
dc.contributor.department
Komplex Rendszerek Fizikája Tanszék
Author institution
dc.contributor.department
Komplex Rendszerek Fizikája Tanszék


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PROBING SPECTROSCOPIC VARIABILITY OF GALAXIES AND NARROW-LINE ACTIVE GALACTIC NUCLEI IN THE SLOAN DIGITAL SKY SURVEY
 

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