Abstract
Variability is characteristic of active galaxies; luminosity variations generally occur at all wavelengths, affecting both continuum and line emission, with timescales and amplitudes depending on the wavelength. We made use of optical variability to select AGNs in the VST-SUDARE survey of the COSMOS field, and confirmed 95 % of them by means of multiwavelength data from overlap** surveys. The analysis returns a sample of AGN candidates with 81 % purity and 15 % completeness with respect to the X-ray confirmed AGNs in the field with an optical counterpart. This study provides an estimate of the reliability of the AGN selection techniques based on variability, which will be used by future wide-field surveys, such as those by LSST.
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References
Baldwin, J.A., Phillips, M.M., Terlevich, R.: Classification parameters for the emission-line spectra of extragalactic objects. PASP 93, 5 (1981)
Botticella, M.T., et al.: SUDARE at the VST. Messenger 151, 29 (2013)
Brandt, W.N., Hasinger, G.: Deep extragalactic X-ray surveys. ARA&A 43, 827 (2005)
Brusa, M., et al.: The XMM-newton wide-field survey in the COSMOS field (XMM-COSMOS): demography and multiwavelength properties of obscured ans unobscured luminous active galactic nuclei. ApJ 716, 348 (2010)
Capaccioli, M., Schipani, P.: The VLT survey telescope opens to the sky: history of a commissioning. Messenger 146, 2 (2011)
Civano, F., et al.: The Chandra COSMOS survey. III. Optical and infrared identification of X-ray point sources. ApJS 201, 30 (2012)
De Cicco, D., et al.: Variability-selected active galactic nuclei in the VST-SUDARE/VOICE survey of the COSMOS field. A&A 574, A112 (2015)
Elvis, M., et al.: Atlas of quasar energy distributions. ApJS 95, 1 (1994)
Fan, X.: Simulation of stellar objects in SDSS color space. AJ 117, 2528 (1999)
Maccacaro, T., et al.: The X-ray spectra of the extragalactic sources in the EINSTEIN extended medium sensitivity survey. ApJ 326, 680 (1988)
Mainieri, V., et al.: XMM-Newton observations of the Lockman Hole. II. Spectral analysis. A&A 393, 425 (2002)
Pereyra, N.A., et al.: Colors of 2625 quasars at 0 ¡ z ¡ 5 measured in the Sloan digital sky survey photometric system. ApJ 642, 87 (2006)
Richards, G.T., et al.: Variability-selected active galactic nuclei from supernova search in the Chandra deep field south. AJ 121, 2308 (2001)
Trevese, D., et al.: A&A 488, 73 (2008)
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De Cicco, D. et al. (2016). Variability-Selected AGNs in the VST-SUDARE Survey of the COSMOS Field. In: Napolitano, N., Longo, G., Marconi, M., Paolillo, M., Iodice, E. (eds) The Universe of Digital Sky Surveys. Astrophysics and Space Science Proceedings, vol 42. Springer, Cham. https://doi.org/10.1007/978-3-319-19330-4_42
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DOI: https://doi.org/10.1007/978-3-319-19330-4_42
Publisher Name: Springer, Cham
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