A SPITZER SPACE TELESCOPE STUDY OF THE DEBRIS DISKS AROUND FOUR SDSS WHITE DWARFS

Journal Article · Tue May 01 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/750/1/86· OSTI ID:22034568

Brinkworth, C S; Girven, J M; Hoard, D W ^[1]; Gaensicke, B T; Marsh, T R; Parsons, S G ^[2]; Koester, D ^[3]

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1. Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)
2. Department of Physics and Astronomy, University of Warwick, Warwick CV4 7AL (United Kingdom)
3. Institut fuer Theoretische Physik und Astrophysik, University of Kiel, 24098 Kiel (Germany)

We present Spitzer Space Telescope data of four isolated white dwarfs that were previously known to harbor circumstellar gaseous disks. Infrared Array Camera photometry shows a significant infrared excess in all of the systems, SDSS0738+1835, SDSS0845+2257, SDSS1043+0855, and SDSS1617+1620, indicative of a dusty extension to those disks. The 4.5 {mu}m excesses seen in SDSS0738, SDSS0845, and SDSS1617 are 7.5, 5.7, and 4.5 times the white dwarf contribution, respectively. In contrast, in SDSS1043, the measured flux density at 4.5 {mu}m is only 1.7 times the white dwarf contribution. We compare the measured IR excesses in the systems to models of geometrically thin, optically thick disks, and find that we are able to match the measured spectral energy distributions to within 3{sigma} of the uncertainties, although disks with unfeasibly hot inner dust temperatures generally provide a better fit than those below the dust sublimation temperature. Possible explanations for the dearth of dust around SDSS1043+0855 are briefly discussed. Including our previous study of SDSS1228+1040, all five white dwarfs with gaseous debris disks have significant amounts of dust around them. It is evident that gas and dust can coexist around these relatively warm, relatively young white dwarfs.

• OSTI ID: 22034568
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 750; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CAMERAS
COMPARATIVE EVALUATIONS
COSMIC DUST
ENERGY SPECTRA
FLUX DENSITY
INFRARED RADIATION
INFRARED SPECTRA
PHOTOMETRY
SUBLIMATION
TELESCOPES
WHITE DWARF STARS