Abstract
We present new Gemini/GMOS optical spectroscopy of 16 extreme variability quasars (EVQs) that dimmed by more than 1.5 mag in the g band between the Sloan Digital Sky Survey (SDSS) and the Dark Energy Survey epochs (separated by a few years in the quasar rest frame). These EVQs are selected from quasars in the SDSS Stripe 82 region, covering a redshift range of 0.5 < z < 2.1. Nearly half of these EVQs brightened significantly (by more than 0.5 mag in the g band) in a few years after reaching their previous faintest state, and some EVQs showed rapid (non-blazar) variations of greater than 1–2 mag on time-scales of only months. To increase sample statistics, we use a supplemental sample of 33 EVQs with multi-epoch spectra from SDSS that cover the broad Mg II λ2798 line. Leveraging on the large dynamic range in continuum variability between the multi-epoch spectra, we explore the associated variations in the broad Mg II line, whose variability properties have not been well studied before. The broad Mg II flux varies in the same direction as the continuum flux, albeit with a smaller amplitude, which indicates at least some portion of Mg II is reverberating to continuum changes. However, the full width at half-maximum (FWHM) of Mg II does not vary accordingly as continuum changes for most objects in the sample, in contrast to the case of the broad Balmer lines. Using the width of broad Mg II to estimate the black hole mass with single epoch spectra therefore introduces a luminosity-dependent bias.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5773-5787 |
| Number of pages | 15 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 493 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2021 |
Keywords
- Black hole physics
- Galaxies: active
- Line: profiles
- Quasars: general
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science
Fingerprint
Dive into the research topics of 'Spectral variability of a sample of extreme variability quasars and implications for the Mg II broad-line region'. Together they form a unique fingerprint.Cite this
- APA
- Standard
- Harvard
- Vancouver
- Author
- BIBTEX
- RIS
Spectral variability of a sample of extreme variability quasars and implications for the Mg II broad-line region. / Yang, Qian; Shen, Yue; Chen, Yu Ching; Liu, Xin; Annis, James; Avila, Santiago; Bertin, Emmanuel; Brooks, David; Buckley-Geer, Elizabeth; Rosell, Aurelio Carnero; Kind, Matias Carrasco; Carretero, Jorge; da Costa, Luiz; Desai, Shantanu; Diehl, H. Thomas; Doel, Peter; Frieman, Josh; Garcia-Bellido, Juan; Gaztanaga, Enrique; Gerdes, David; Gruen, Daniel; Gruendl, Robert; Gschwend, Julia; Gutierrez, Gaston; Hollowood, Devon L.; Honscheid, Klaus; Hoyle, Ben; James, David; Krause, Elisabeth; Kuehn, Kyler; Lidman, Christopher; Lima, Marcos; Maia, Marcio; Marshall, Jennifer; Martini, Paul; Menanteau, Felipe; Miquel, Ramon; Malagón, Andrés Plazas; Sanchez, Eusebio; Scarpine, Vic; Schindler, Rafe; Schubnell, Michael; Serrano, Santiago; Sevilla, Ignacio; Smith, Mathew; Soares-Santos, Marcelle; Sobreira, Flavia; Suchyta, Eric; Swanson, Molly; Tarle, Gregory; Vikram, Vinu; Walker, Alistair.
In: Monthly Notices of the Royal Astronomical Society, Vol. 493, No. 4, 01.04.2021, p. 5773-5787.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Spectral variability of a sample of extreme variability quasars and implications for the Mg II broad-line region
AU - Yang, Qian
AU - Shen, Yue
AU - Chen, Yu Ching
AU - Liu, Xin
AU - Annis, James
AU - Avila, Santiago
AU - Bertin, Emmanuel
AU - Brooks, David
AU - Buckley-Geer, Elizabeth
AU - Rosell, Aurelio Carnero
AU - Kind, Matias Carrasco
AU - Carretero, Jorge
AU - da Costa, Luiz
AU - Desai, Shantanu
AU - Diehl, H. Thomas
AU - Doel, Peter
AU - Frieman, Josh
AU - Garcia-Bellido, Juan
AU - Gaztanaga, Enrique
AU - Gerdes, David
AU - Gruen, Daniel
AU - Gruendl, Robert
AU - Gschwend, Julia
AU - Gutierrez, Gaston
AU - Hollowood, Devon L.
AU - Honscheid, Klaus
AU - Hoyle, Ben
AU - James, David
AU - Krause, Elisabeth
AU - Kuehn, Kyler
AU - Lidman, Christopher
AU - Lima, Marcos
AU - Maia, Marcio
AU - Marshall, Jennifer
AU - Martini, Paul
AU - Menanteau, Felipe
AU - Miquel, Ramon
AU - Malagón, Andrés Plazas
AU - Sanchez, Eusebio
AU - Scarpine, Vic
AU - Schindler, Rafe
AU - Schubnell, Michael
AU - Serrano, Santiago
AU - Sevilla, Ignacio
AU - Smith, Mathew
AU - Soares-Santos, Marcelle
AU - Sobreira, Flavia
AU - Suchyta, Eric
AU - Swanson, Molly
AU - Tarle, Gregory
AU - Vikram, Vinu
AU - Walker, Alistair
N1 - Funding Information: 2IRAF is the Image Reduction and Analysis Facility, written and supported by the National Optical Astronomy Observatories (NOAO) operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation. Funding Information: We thank the referee, Andy Lawrence, for useful comments that improved the manuscript. QY and YS acknowledge support from an Alfred P. Sloan Research Fellowship (YS) and NSF grant AST-1715579. We thank Patrick Hall, Tamara Davis, Shu Wang, and Hengxiao Guo for useful discussions and suggestions. Funding Information: Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundac¸ão Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovac¸ão, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the Dark Energy Survey. Funding Information: Based in part on observations at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Funding Information: The DES data management system is supported by the National Science Foundation under Grant Numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015-71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciênciae Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2). Funding Information: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. Funding Information: Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III website is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. Funding Information: The PS1 has been made possible through contributions by the ‘Institute for Astronomy’, the University of Hawaii, the ‘Pan-STARRS Project Office’, the ‘Max-Planck Society’ and its participating institutes, the ‘Max Planck Institute for Astronomy, Heidelberg’, and the ‘Max Planck Institute for Extraterrestrial Physics, Garching’, ‘The Johns Hopkins University’, Durham University, the University of Edinburgh, ‘Queen’s University Belfast’, the Harvard-Smithsonian Center for Astrophysics, the ‘Las Cumbres Observatory Global Telescope Network Incorporated’, ‘the National Central University of Taiwan’, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, and Eotvos Lorand University (ELTE). Publisher Copyright: © 2020 The Author(s)
PY - 2021/4/1
Y1 - 2021/4/1
N2 - We present new Gemini/GMOS optical spectroscopy of 16 extreme variability quasars (EVQs) that dimmed by more than 1.5 mag in the g band between the Sloan Digital Sky Survey (SDSS) and the Dark Energy Survey epochs (separated by a few years in the quasar rest frame). These EVQs are selected from quasars in the SDSS Stripe 82 region, covering a redshift range of 0.5 < z < 2.1. Nearly half of these EVQs brightened significantly (by more than 0.5 mag in the g band) in a few years after reaching their previous faintest state, and some EVQs showed rapid (non-blazar) variations of greater than 1–2 mag on time-scales of only months. To increase sample statistics, we use a supplemental sample of 33 EVQs with multi-epoch spectra from SDSS that cover the broad Mg II λ2798 line. Leveraging on the large dynamic range in continuum variability between the multi-epoch spectra, we explore the associated variations in the broad Mg II line, whose variability properties have not been well studied before. The broad Mg II flux varies in the same direction as the continuum flux, albeit with a smaller amplitude, which indicates at least some portion of Mg II is reverberating to continuum changes. However, the full width at half-maximum (FWHM) of Mg II does not vary accordingly as continuum changes for most objects in the sample, in contrast to the case of the broad Balmer lines. Using the width of broad Mg II to estimate the black hole mass with single epoch spectra therefore introduces a luminosity-dependent bias.
AB - We present new Gemini/GMOS optical spectroscopy of 16 extreme variability quasars (EVQs) that dimmed by more than 1.5 mag in the g band between the Sloan Digital Sky Survey (SDSS) and the Dark Energy Survey epochs (separated by a few years in the quasar rest frame). These EVQs are selected from quasars in the SDSS Stripe 82 region, covering a redshift range of 0.5 < z < 2.1. Nearly half of these EVQs brightened significantly (by more than 0.5 mag in the g band) in a few years after reaching their previous faintest state, and some EVQs showed rapid (non-blazar) variations of greater than 1–2 mag on time-scales of only months. To increase sample statistics, we use a supplemental sample of 33 EVQs with multi-epoch spectra from SDSS that cover the broad Mg II λ2798 line. Leveraging on the large dynamic range in continuum variability between the multi-epoch spectra, we explore the associated variations in the broad Mg II line, whose variability properties have not been well studied before. The broad Mg II flux varies in the same direction as the continuum flux, albeit with a smaller amplitude, which indicates at least some portion of Mg II is reverberating to continuum changes. However, the full width at half-maximum (FWHM) of Mg II does not vary accordingly as continuum changes for most objects in the sample, in contrast to the case of the broad Balmer lines. Using the width of broad Mg II to estimate the black hole mass with single epoch spectra therefore introduces a luminosity-dependent bias.
KW - Black hole physics
KW - Galaxies: active
KW - Line: profiles
KW - Quasars: general
UR - http://www.scopus.com/inward/record.url?scp=85087357485&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85087357485&partnerID=8YFLogxK
U2 - 10.1093/mnras/staa645
DO - 10.1093/mnras/staa645
M3 - Article
AN - SCOPUS:85087357485
VL - 493
SP - 5773
EP - 5787
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -