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Title: Near-infrared spectra and intrinsic luminosities of candidate type II quasars at 2 < z < 3.4

We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey (SDSS), using Triplespec on the Apache Point Observatory 3.5 m telescope, the Folded-port InfraRed Echellette at the Magellan/Baade 6.5 m telescope, and the Gemini Near-Infrared Spectrograph on Gemini. At redshifts of 2 < z < 3.4, our NIR spectra probe the rest-frame optical region of these targets, which were initially selected to have strong lines of C IV and Ly α, with FWHM < 2000 km s{sup –1} from the SDSS pipeline. We use the [O III] λ5007 line shape as a model for the narrow-line region emission and find that Hα consistently requires a broad component with FWHMs ranging from 1000 to 7500 km s{sup –1}. Interestingly, the C IV lines also require broad bases, but with considerably narrower widths of 1000-4500 km s{sup –1}. Estimating the extinction using the Balmer decrement and also the relationship in lower-z quasars between rest equivalent width and luminosity in the [O III] line, we find typical A{sub V} values of 0-2 mag, which naturally explains the attenuated C IV lines relative to Hα. We propose that our targets are moderately obscured quasars. Wemore » also describe one unusual object with three distinct velocity peaks in its [O III] spectrum.« less
Authors:
; ;  [1] ; ; ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ; ;  [7] ;  [8]
  1. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
  2. Center for Astrophysical Sciences, Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)
  3. McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)
  4. Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States)
  5. Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)
  6. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)
  7. Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)
  8. University of Chicago Astronomy and Astrophysics Department and Enrico Fermi Institute, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
Publication Date:
OSTI Identifier:
22356632
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 788; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BALMER LINES; BLACK HOLES; EMISSION; INFRARED SPECTRA; ISOCHRONOUS CYCLOTRONS; LUMINOSITY; LYMAN LINES; NEAR INFRARED RADIATION; QUASARS; RED SHIFT; TELESCOPES; VELOCITY