Spectral evolution in high redshift quasars from the final boss sample

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Publication Type honors thesis
School or College College of Science
Department Physics
Faculty Mentor Kyle Dawson
Creator Jensen, Trey W.
Title Spectral evolution in high redshift quasars from the final boss sample
Year graduated 2015
Description We report on a study of the spectral variations in a sample of 102,150 quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III). After mitigating selection effects and Malmquist bias over the redshift range 2:1 □ z □ 3:5, we create high signal-to-noise composite spectra binned by luminosity, spectral index, and redshift. We use these composite spectra to inspect the variations in quasar properties as a function of each of these three parameters. We confirm the traditional Bald­ win effect (i.e. the anti-correlation of C IV equivalent width and luminosity) that follows the relation W |j Lbw with slope bw = D0:80 □ 0:005;D0:76 □ 0:006; mid □ 0:88 □ 0:006 for z= 2:26; 2:46; rnd 2:84 respectively. We also observe for a unit change in the spectral index, redder quasars exhibit an apparent outflow in C IV with a velocity 3100 □ 80 kms~1 relative to the estimated systemic redshift. Finally, we find evidence for redshift evolution in average quasar spectral features, even at a fixed luminosity. This evolution has a signa­ ture nearly identical to the signature of the Baldwin effect. The two trends are correlated at 94%, indicating that they arise from the same physical mechanism. We argue that this spectral variation is likely the signature of varying accretion efficiency.
Type Text
Publisher University of Utah
Subject Quasars -- Spectra; Red shift -- Observations; Baryon Oscillation Spectroscopic Survey; Sloan Digital Sky Survey; Redshift evolution
Language eng
Rights Management Copyright © Trey W. Jensen 2016
Format Medium application/pdf
Format Extent 25,409 bytes
Identifier etd3/id/3684
Permissions Reference URL https://collections.lib.utah.edu/ark:/87278/s6hf1q4h
ARK ark:/87278/s6zh01hh
Setname ir_htoa
Date Created 2016-02-01
Date Modified 2018-10-29
ID 197235
Reference URL https://collections.lib.utah.edu/ark:/87278/s6zh01hh