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Spitzer Observations of GD 362 and Other Metal-Rich White Dwarfs

J. Farihi·B. Zuckerman·E. E. Becklin·M. Jura
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Abstract

A {\em Spitzer} IRAC survey of 17 nearby metal-rich white dwarfs, nominally DAZ stars, reveals excess emission from only 3 targets: G29-38, GD 362 and G167-8. Observations of GD 362 with all three {\em Spitzer} instruments reveals a warm ($\approx1000$ K) dust continuum, very strong silicate emission, and the likely presence of cooler ($\approx500$ K) dust. While there is a general similarity between the mid-infrared spectral energy distributions of G29-38 and GD 362, the IRAC fluxes of G167-8 are so far unique among white dwarfs. However, further observations of G167-8 are required before the measured excess can be definitely associated with the white dwarf.

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J. Farihi, B. Zuckerman, E. E. Becklin, M. Jura. 2006-10-04. Spitzer Observations of GD 362 and Other Metal-Rich White Dwarfs. https://arxiv.org/abs/astro-ph/0610101

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