• DOI:10.1088/0004-637X/760/1/26
• Corpus ID: 119190880

THE FREQUENCY OF DEBRIS DISKS AT WHITE DWARFS

@article{Barber2012THEFO,
  title={THE FREQUENCY OF DEBRIS DISKS AT WHITE DWARFS},
  author={Sara D. Barber and Adam J. Patterson and Mukremin Kilic and Sandy K. Leggett and P. Dufour and Joshua S. Bloom and Dan L. Starr},
  journal={The Astrophysical Journal},
  year={2012},
  volume={760}
}

• S. Barber, A. Patterson, +4 authors D. Starr
• Published 14 September 2012
• Physics, Geology
• The Astrophysical Journal

We present near- and mid-infrared photometry and spectroscopy from PAIRITEL, IRTF, and Spitzer of a metallicity-unbiased sample of 117 cool, hydrogen-atmosphere white dwarfs (WDs) from the Palomar-Green survey and find five with excess radiation in the infrared, translating to a 4.3+2.7− 1.2% frequency of debris disks. This is slightly higher than, but consistent with the results of previous surveys. Using an initial–final mass relation, we apply this result to the progenitor stars of our sample and conclude that 1–7 M☉ stars have at least a 4.3% chance of hosting planets; an indirect probe of the intermediate-mass regime eluding conventional exoplanetary detection methods. Alternatively, we interpret this result as a limit on accretion timescales as a fraction of WD cooling ages; WDs accrete debris from several generations of disks for ∼10 Myr. The average total mass accreted by these stars ranges from that of 200 km asteroids to Ceres-sized objects, indicating that WDs accrete moons and dwarf planets as well as solar system asteroid analogs.