SDSS unveils a population of intrinsically faint cataclysmic variables at the minimum orbital period
Gänsicke, B. T. (Boris T.), Dillon, Monihar, Southworth, J. (John), Thorstensen, John Robert, Rodriguez-Gil, P., Aungwerojwit, A. (Amornrat), Marsh, T. R., Szkody, Paula, Barros, S. C. C., Casares, J., de Martino, Domitilla, Groot, P. J. (Paul J.), Hakala, P., Kolb, U., Littlefair, S. P., Martinez-Pais, I. G., Nelemans, G. and Schreiber, Matthias R. (2009) SDSS unveils a population of intrinsically faint cataclysmic variables at the minimum orbital period. Monthly Notices of the Royal Astronomical Society, Vol.397 (No.4). pp. 2170-2188. ISSN 0035-8711Full text not available from this repository.
Official URL: http://dx.doi.org/10.1111/j.1365-2966.2009.15126.x
We discuss the properties of 137 cataclysmic variables (CVs) which are included in the Sloan Digital Sky Survey (SDSS) spectroscopic data base, and for which accurate orbital periods have been measured. 92 of these systems are new discoveries from SDSS and were followed-up in more detail over the past few years. 45 systems were previously identified as CVs because of the detection of optical outbursts and/or X-ray emission, and subsequently re-identified from the SDSS spectroscopy. The period distribution of the SDSS CVs differs dramatically from that of all the previously known CVs, in particular it contains a significant accumulation of systems in the orbital period range 80-86 min. We identify this feature as the elusive 'period minimum spike' predicted by CV population models, which resolves a long-standing discrepancy between compact binary evolution theory and observations. We show that this spike is almost entirely due to the large number of CVs with very low accretion activity identified by SDSS. The optical spectra of these systems are dominated by emission from the white dwarf photosphere, and display little or no spectroscopic signature from the donor stars, suggesting very low mass companion stars. We determine the average absolute magnitude of these low-luminosity CVs at the period minimum to be << M-g >> = 11.6 +/- 0.7. Comparison of the SDSS CV sample to the CVs found in the Hamburg Quasar Survey and the Palomar Green Survey suggests that the depth of SDSS is the key ingredient resulting in the discovery of a large number of intrinsically faint short-period systems.
|Item Type:||Journal Item|
|Subjects:||Q Science > QB Astronomy|
|Divisions:||Faculty of Science > Physics|
|Library of Congress Subject Headings (LCSH):||Double stars, Dwarf novae, Stars -- Evolution, Stars, New, Cataclysmic variable stars|
|Journal or Publication Title:||Monthly Notices of the Royal Astronomical Society|
|Date:||21 August 2009|
|Number of Pages:||19|
|Page Range:||pp. 2170-2188|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Science and Technology Facilities Council (Great Britain), National Science Foundation (U.S.) (NSF), Thailand, Fundação para a Ciência e a Tecnologia (FCT), Fondo Nacional de Desarrollo Científico y Tecnológico (Chile) (FONDECYT), Alfred P. Sloan Foundation|
|Grant number:||AST-0307413 (NSF), AST-0708810 (NSF), AST 02-05875 (NSF), 1061199 (FONDECYT)|
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