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Measuring Quasar Variability with Pan-STARRS1 and SDSS
- Source :
- The Astrophysical Journal
- Publication Year :
- 2014
- Publisher :
- arXiv, 2014.
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Abstract
- We measure quasar variability using the Panoramic Survey Telescope and Rapid Response System 1 Survey (Pan-STARRS1 or PS1) and the Sloan Digital Sky Survey (SDSS) and establish a method of selecting quasars via their variability in 10{sup 4} deg{sup 2} surveys. We use 10{sup 5} spectroscopically confirmed quasars that have been well measured in both PS1 and SDSS and take advantage of the decadal timescales that separate SDSS measurements and PS1 measurements. A power law model fits the data well over the entire time range tested, 0.01-10 yr. Variability in the current PS1-SDSS data set can efficiently distinguish between quasars and nonvarying objects. It improves the purity of a griz quasar color cut from 4.1% to 48% while maintaining 67% completeness. Variability will be very effective at finding quasars in data sets with no u band and in redshift ranges where exclusively photometric selection is not efficient. We show that quasars' rest-frame ensemble variability, measured as a root mean squared in Δ magnitudes, is consistent with V(z, L, t) = A {sub 0}(1 + z){sup 0.37}(L/L {sub 0}){sup –0.16}(t/1 yr){sup 0.246}, where L {sub 0} = 10{sup 46} erg s{sup –1} and A {sub 0} = 0.190, 0.162, 0.147, ormore » 0.141 in the g {sub P1}, r {sub P1}, i {sub P1}, or z {sub P1}filter, respectively. We also fit across all four filters and obtain median variability as a function of z, L, and λ as V(z, L, λ, t) = 0.079(1 + z){sup 0.15}(L/L {sub 0}){sup –0.2}(λ/1000 nm){sup –0.44}(t/1 yr){sup 0.246}.« less
- Subjects :
- Physics
High Energy Astrophysical Phenomena (astro-ph.HE)
media_common.quotation_subject
FOS: Physical sciences
Astronomy and Astrophysics
Quasar
Astrophysics
Power law
Redshift
Red shift
Root mean square
13. Climate action
Space and Planetary Science
Sky
Astrophysics - High Energy Astrophysical Phenomena
Astrophysics - Instrumentation and Methods for Astrophysics
Spectroscopy
Time range
Instrumentation and Methods for Astrophysics (astro-ph.IM)
media_common
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal
- Accession number :
- edsair.doi.dedup.....51e93461ff15786468436a17b144e317
- Full Text :
- https://doi.org/10.48550/arxiv.1407.0716