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Title: THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS

Abstract

Low-ionization (Mg II, Fe II, and Fe III) broad absorption line quasars (LoBALs) probe a relatively obscured quasar population and could be at an early evolutionary stage for quasars. We study the intrinsic fractions of LoBALs using the Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey, and Faint Images of the Radio Sky at Twenty cm survey. We find that the LoBAL fractions of the near-infrared (NIR) and radio samples are approximately 5-7 times higher than those measured in the optical sample. This suggests that the fractions measured in the NIR and radio bands are closer to the intrinsic fractions of the populations, and that the optical fractions are significantly biased due to obscuration effects, similar to high-ionization broad absorption line quasars (HiBALs). Considering a population of obscured quasars that do not enter the SDSS, which could have a much higher LoBAL fraction, we expect that the intrinsic fraction of LoBALs could be even higher. We also find that the LoBAL fractions decrease with increasing radio luminosities, again, similarly to HiBALs. In addition, we find evidence for increasing fractions of LoBALs toward higher NIR luminosities, especially for FeLoBALs with a fraction of {approx}18% at M{sub K{sub s}}< -31more » mag. This population of NIR-luminous LoBALs may be at an early evolutionary stage of quasar evolution. To interpret the data, we use a luminosity-dependent model for LoBALs that yields significantly better fits than those from a pure geometric model.« less

Authors:
 [1];  [2]
  1. Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)
  2. GEPI, Observatoire de Paris, CNRS, University of Paris Diderot, 5 Place Jules Janssen, F-92195 Meudon (France)
Publication Date:
OSTI Identifier:
22092141
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 757; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTRA; ASTROPHYSICS; GALAXIES; IMAGES; IONIZATION; IRON IONS; LUMINOSITY; MAGNESIUM IONS; NEAR INFRARED RADIATION; PROBES; QUASARS; RADIOASTRONOMY; STAR EVOLUTION

Citation Formats

Xinyu, Dai, Shankar, Francesco, and Sivakoff, Gregory R., E-mail: xdai@ou.edu. THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS. United States: N. p., 2012. Web. doi:10.1088/0004-637X/757/2/180.
Xinyu, Dai, Shankar, Francesco, & Sivakoff, Gregory R., E-mail: xdai@ou.edu. THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS. United States. https://doi.org/10.1088/0004-637X/757/2/180
Xinyu, Dai, Shankar, Francesco, and Sivakoff, Gregory R., E-mail: xdai@ou.edu. 2012. "THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS". United States. https://doi.org/10.1088/0004-637X/757/2/180.
@article{osti_22092141,
title = {THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS},
author = {Xinyu, Dai and Shankar, Francesco and Sivakoff, Gregory R., E-mail: xdai@ou.edu},
abstractNote = {Low-ionization (Mg II, Fe II, and Fe III) broad absorption line quasars (LoBALs) probe a relatively obscured quasar population and could be at an early evolutionary stage for quasars. We study the intrinsic fractions of LoBALs using the Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey, and Faint Images of the Radio Sky at Twenty cm survey. We find that the LoBAL fractions of the near-infrared (NIR) and radio samples are approximately 5-7 times higher than those measured in the optical sample. This suggests that the fractions measured in the NIR and radio bands are closer to the intrinsic fractions of the populations, and that the optical fractions are significantly biased due to obscuration effects, similar to high-ionization broad absorption line quasars (HiBALs). Considering a population of obscured quasars that do not enter the SDSS, which could have a much higher LoBAL fraction, we expect that the intrinsic fraction of LoBALs could be even higher. We also find that the LoBAL fractions decrease with increasing radio luminosities, again, similarly to HiBALs. In addition, we find evidence for increasing fractions of LoBALs toward higher NIR luminosities, especially for FeLoBALs with a fraction of {approx}18% at M{sub K{sub s}}< -31 mag. This population of NIR-luminous LoBALs may be at an early evolutionary stage of quasar evolution. To interpret the data, we use a luminosity-dependent model for LoBALs that yields significantly better fits than those from a pure geometric model.},
doi = {10.1088/0004-637X/757/2/180},
url = {https://www.osti.gov/biblio/22092141}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 757,
place = {United States},
year = {Mon Oct 01 00:00:00 EDT 2012},
month = {Mon Oct 01 00:00:00 EDT 2012}
}