Quantifying Quasar Variability As Part of a General Approach To Classifying Continuously Varying Sources

Abstract

Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular transient events (supernovae, novae, microlensing), there is no equivalent for non-periodic continuously varying sources (quasars, aperiodic stellar variability). In this paper we present a fast method for modeling and classifying such sources. We demonstrate the method using ~ 86,000 variable sources from the OGLE-II survey of the LMC and ~ 2,700 mid-IR selected quasar candidates from the OGLE-III survey of the LMC and SMC. We discuss the location of common variability classes in the parameter space of the model. In particular we show that quasars occupy a distinct region of variability space, providing a simple quantitative approach to the variability selection of quasars.

Accepted for publication in ApJ

References in corpus (9)

• Low Resolution Spectral Templates For AGNs and Galaxies From 0.03 -- 30 microns
• The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations
• The CFHTLS Strong Lensing Legacy Survey: I. Survey overview and T0002 release sample
• Light and Motion in SDSS Stripe 82: The Catalogues
• The OGLE View of Microlensing towards the Magellanic Clouds. I. A Trickle of Events in the OGLE-II LMC data
• Discovery of 5000 Active Galactic Nuclei behind the Magellanic Clouds
• The Mid-Infrared Properties of X-ray Sources
• Self-Organizing Maps. An application to the OGLE data and the Gaia Science Alerts
• Exploring the Variable Sky with the Sloan Digital Sky Survey

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