Debris Disks around White Dwarfs: The DAZ Connection

2006/03/28 by Mukremin Kilic, Ted von Hippel, S. K. Leggett +1 · 9 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Debris #Debris disk #Infrared #Infrared excess #Infrared telescope #Pulsars and Gravitational Waves Research #Stars #Stellar, planetary, and galactic studies #Telescope #White dwarf #astro-ph

paper · pdf · doi:10.1086/504682

published as Astrophys.J. 646 (2006) 474-479 · ApJ, in press

arxiv created 2006/03/28 · openalex publication_date 2006/07/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We present near-infrared spectroscopic observations of 20 previously known DAZ white dwarfs obtained at the NASA Infrared Telescope Facility. Two of these white dwarfs (G29-38 and GD362) are known to display significant K-band excesses due to circumstellar debris disks. Here we report the discovery of excess K-band radiation from another DAZ white dwarf, WD0408-041 (GD56). Using spectroscopic observations, we show that the excess radiation cannot be explained by a stellar or substellar companion, and is likely to be caused by a warm debris disk. Our observations strengthen the connection between the debris disk phenomena and the observed metal abundances in cool DAZ white dwarfs. However, we do not find any excess infrared emission from the most metal rich DAZs with T_{\rm eff}= 16000 -- 20000 K. This suggests that the metal abundances in warmer DAZ white dwarfs may require another explanation.

Citations

• Spectroscopic Identification of Cool White Dwarfs in the Solar Neighborhood
• Spextool: A Spectral Extraction Package for SpeX, a 0.8–5.5 Micron Cross‐Dispersed Spectrograph
• SpeX: A Medium‐Resolution 0.8–5.5 Micron Spectrograph and Imager for the NASA Infrared Telescope Facility
• A Method of Correcting Near‐Infrared Spectra for Telluric Absorption1
• The Dust Cloud around the White Dwarf G29-38

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