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An Illustration of Modeling Cataclysmic Variables: HST, FUSE, and SDSS Spectra of SDSS J080908.39+381406.2

Linnell, Albert P. and Hoard, D. W. and Szkody, Paula and Long, Knox S. and Hubeny, Ivan and Gänsicke, Boris and Sion, Edward M. (2007) An Illustration of Modeling Cataclysmic Variables: HST, FUSE, and SDSS Spectra of SDSS J080908.39+381406.2. Astrophysical Journal, 654 (2). pp. 1036-1051. ISSN 0004-637X. doi:10.1086/507455.

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FUSE, HST, and SDSS spectra of the cataclysmic variable SDSS J080908.39+381406.2 provide a spectral flux distribution from 900 to 9200 Å. This data set is used to illustrate procedures for calculating and testing system models. The spectra are not contemporaneous; it is necessary to assume that the combined spectra are representative of the system. The illustrations are based on a system with a 1.0 M_⊙ white dwarf, a 0.30 M_⊙, 3500 K, Roche lobe-filling secondary star, and an accretion disk extending to the tidal cutoff radius. Assuming a similar accretion state for the nonsimultaneous spectra, the best standard model fit is with a mass transfer rate of 3.0 × 10^(-9)M_⊙ yr^(-1). Extensive simulations demonstrate that the accretion disk must be truncated at its inner edge if the temperature profile follows the standard model, but truncated models face severe objections, which we address. Following additional simulation tests, we obtain a model accretion disk with a temperature profile comparable to the profile for SW Sex as determined from tomographic image reconstruction. This model fits the discovery SDSS spectrum well but has a flux deficit in the UV and FUV. Emission from a white dwarf is a plausible source of additional flux. Adding this source to the disk synthetic spectrum produces FUV flux that can explain the observed flux. An additional (archival) SDSS spectrum is fainter by about 0.3 mag in the optical. Additional analysis showed that UV residuals from a model fitting the archival optical wavelength spectrum are unacceptably large. Contemporaneous spectra from all wavelength regions would be necessary for a reliable system model. Our discussion illustrates how this conclusion follows from the system models.

Item Type:Article
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URLURL TypeDescription
Hoard, D. W.0000-0002-6800-6519
Gänsicke, Boris0000-0002-2761-3005
Additional Information:© 2007 The American Astronomical Society. Received 2005 October 24; accepted 2006 June 30. The authors thank the anonymous referee for detailed comments; addressing them has greatly improved the presentation. The research described in this paper was carried out, in part, at the Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the National Aeronautics and Space Administration. P. S., D. W. H., K. S. L., and A. P. L. are grateful for support from NASA FUSE grant NAG5-13656, NASA HST grants GO-09357.06, GO-09724, and AR-10674, and NSF grant AST 02-05875. B. T. G. was supported by a PPARC Advanced Fellowship.
Funding AgencyGrant Number
NSFAST 02-05875
Particle Physics and Astronomy Research Council (PPARC)UNSPECIFIED
Subject Keywords:accretion, accretion disks; novae, cataclysmic variables; stars : individual (SDSS J0809); ultraviolet : stars; white dwarfs
Issue or Number:2
Record Number:CaltechAUTHORS:20100205-110201587
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Official Citation:An Illustration of Modeling Cataclysmic Variables: HST, FUSE, and SDSS Spectra of SDSS J080908.39+381406.2 Albert P. Linnell, D. W. Hoard, Paula Szkody, Knox S. Long, Ivan Hubeny, Boris Gänsicke, and Edward M. Sion 2007 ApJ 654 1036-1051 doi: 10.1086/507455
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17397
Deposited By: Tony Diaz
Deposited On:09 Feb 2010 03:36
Last Modified:08 Nov 2021 23:35

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