Changing-look AGN. I. Main sequence transition Virtual Observatory Resource

Authors
  1. Panda S.
  2. Sniegowska M.
  3. Published by
    CDS
Abstract

This paper is the first in a series of papers that prepare and analyze spectral and other properties for a database of already-discovered changing-look active galactic nuclei (CL AGNs). Here we focus on the spectral fitting and analysis of broad emission lines in a sample of 93 CL AGNs collected from the literature with existing Sloan Digital Sky Survey (SDSS)/Baryon Oscillation Spectroscopic Survey (BOSS)/extended-BOSS spectroscopy where the H{beta} emission-line profile does not completely disappear in any epochs. Additionally, we have gathered older/newer spectral epochs from all the available SDSS data releases to make the database more complete. We use PyQSOFit and perform a homogeneous spectral decomposition of all of our SDSS spectra and tabulate the AGN continuum and emission-line properties per epoch per source, chronologically. This further allows us to categorize the sources in our sample as Turn-On or Turn-Off and subsequently check for repeated occurrences of such phases. We then estimate the black hole mass (M_BH_) and the Eddington ratio ({lambda}_Edd_) per epoch per source where the required parameters are available and well estimated. We demonstrate the movement of the source in the M_BH_-{lambda}_Edd_ plane, allowing us to check for systematic changes in the source's fundamental properties. We then track their transition along the optical plane of the Eigenvector 1 schema and categorize sources that either stay within the same population (A or B) or make an interpopulation movement as a function of spectral epoch. We also test the Balmer decrement (H{alpha}/H{beta}) of a subset of our sample of CL AGNs as a function of time and AGN luminosity.

Keywords
  1. active-galactic-nuclei
  2. visible-astronomy
  3. spectroscopy
  4. redshifted
  5. line-intensities
  6. black-holes
Bibliographic source Bibcode
2024ApJS..272...13P
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/272/13
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJS/272/13

Access

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http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/272/13
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/272/13
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/272/13
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/272/13/table2?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/272/13/table2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/272/13/table2?

History

2024-11-08T16:45:42Z
Resource record created
2024-11-08T16:03:02Z
Updated
2024-11-08T16:45:42Z
Created

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr