ENSTATITE-RICH WARM DEBRIS DUST AROUND HD165014
- Department of Astronomy, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
- National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)
- Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka (Japan)
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)
- Astronomical Institute, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578 (Japan)
We present the Spitzer/Infrared Spectrograph spectrum of the main-sequence star HD165014, which is a warm ({approx_gt}200 K) debris disk candidate discovered by the AKARI All-Sky Survey. The star possesses extremely large excess emission at wavelengths longer than 5 {mu}m. The detected flux densities at 10 and 20 {mu}m are {approx}10 and {approx}30 times larger than the predicted photospheric emission, respectively. The excess emission is attributable to the presence of circumstellar warm dust. The dust temperature is estimated as 300-750 K, corresponding to the distance of 0.7-4.4 AU from the central star. Significant fine-structured features are seen in the spectrum and the peak positions are in good agreement with those of crystalline enstatite. Features of crystalline forsterite are not significantly seen. HD165014 is the first debris disk sample that has enstatite as a dominant form of crystalline silicate rather than forsterite. Possible formation of enstatite dust from differentiated parent bodies is suggested according to the solar system analog. The detection of an enstatite-rich debris disk in the current study suggests the presence of large bodies and a variety of silicate dust processing in warm debris disks.
- OSTI ID:
- 21448937
- Journal Information:
- Astrophysical Journal Letters, Vol. 714, Issue 1; Other Information: DOI: 10.1088/2041-8205/714/1/L152; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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