Journal article
Characterizing Quasar C IV Emission-line Measurements from Time-resolved Spectroscopy
The Astrophysical journal, v 899(2)
01 Aug 2020
Abstract
We use multiepoch quasar spectroscopy to determine how accurately single-epoch spectroscopy can locate quasars in emission-line parameter space in order to inform investigations where time-resolved spectroscopy is not available. We explore the improvements in emission-line characterization that result from using nonparametric information from many lines as opposed to a small number of parameters for a single line, utilizing reconstructions based on an independent component analysis applied to the data from the Sloan Digital Sky Survey Reverberation Mapping project. We find that most of the quasars are well described by just two components, while more components signal a quasar likely to yield a successful reverberation mapping analysis. In single-epoch spectroscopy the apparent variability of equivalent width is exaggerated because it is dependent on the continuum. Multiepoch spectroscopy reveals that single-epoch results do not significantly change where quasars are located in Civparameter space and do not have a significant impact on investigations of the global Baldwin effect. Quasars with emission-line properties indicative of higherL/L(Edd)are less variable, consistent with models with enhanced accretion disk density. Narrow absorption features at the systemic redshift may be indicative of orientation (including radio-quiet quasars) and may appear in as much as 20% of the quasar sample. Future work applying these techniques to lower-luminosity quasars will be important for understanding the nature of accretion disk winds.
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Details
- Title
- Characterizing Quasar C IV Emission-line Measurements from Time-resolved Spectroscopy
- Creators
- Angelica B. Rivera - Drexel UniversityGordon T. Richards - Drexel UniversityPaul C. Hewett - University of CambridgeAmy L. Rankine - University of Cambridge
- Publication Details
- The Astrophysical journal, v 899(2)
- Publisher
- Iop Publishing Ltd
- Number of pages
- 16
- Grant note
- University of Notre Dame New York University Universidad Nacional Autonoma de Mexico HST-GO-14135.001-A; HST-AR-15048.001-A / NASA through Space Telescope Science Institute; Space Telescope Science Institute University of Utah AST-1908716 / National Science Foundation; National Science Foundation (NSF) Harvard-Smithsonian Center for Astrophysics; Smithsonian Institution Lawrence Berkeley National Laboratory; United States Department of Energy (DOE) Observatario Nacional/MCTI Ohio State University Vanderbilt University Center for High-Performance Computing at the University of Utah Max-Planck-Institut fur Astronomie (MPIA Heidelberg) Carnegie Institution for Science National Astronomical Observatories of China Chilean Participation Group U.S. Department of Energy Office of Science; United States Department of Energy (DOE) Alfred P. Sloan Foundation Carnegie Mellon University Max-Planck-Institut fur Astrophysik (MPA Garching) United Kingdom Participation Group University of Washington Instituto de Astrofisica de Canarias University of Wisconsin Max-Planck-Institut fur Extraterrestrische Physik (MPE) University of Arizona Yale University New Mexico State University Pennsylvania State University University of Oxford NAS5-26555 / NASA; National Aeronautics & Space Administration (NASA) University of Portsmouth Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo Brazilian Participation Group French Participation Group University of Colorado Boulder University of Virginia Leibniz Institut fur Astrophysik Potsdam (AIP) Shanghai Astronomical Observatory Korean Participation Group Johns Hopkins University
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Physics
- Web of Science ID
- WOS:000563104700001
- Scopus ID
- 2-s2.0-85091002841
- Other Identifier
- 991019169911804721
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- Collaboration types
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Astronomy & Astrophysics