FORMATION AND EVOLUTION OF PLANETARY SYSTEMS: PROPERTIES OF DEBRIS DUST AROUND SOLAR-TYPE STARS

Journal Article · Sun Mar 15 04:00:00 EDT 2009 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/181/1/197; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21269251

Carpenter, John M; Hillenbrand, Lynne A ^[1]; Bouwman, Jeroen; Henning, Thomas; Wolf, Sebastian ^[2]; Mamajek, Eric E ^[3]; Meyer, Michael R; Kim, Jinyoung Serena; Pascucci, Ilaria ^[4]; Backman, Dana E ^[5]; Hines, Dean C ^[6]; Hollenbach, David ^[7]; Moro-Martin, Amaya ^[8]; Silverstone, Murray D ^[9]; Stauffer, John R ^[10]

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1. Department of Astronomy, California Institute of Technology, Mail Code 105-24, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
2. Max-Planck-Institut fuer Astronomie, D-69117 Heidelberg (Germany)
3. Harvard-Smithsonian Center for Astrophysics (United States)
4. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
5. SOFIA/SETI Institute (Bulgaria)
6. Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States)
7. NASA-Ames Research Center (United States)
8. Department of Astrophysical Science, Princeton University (United States)
9. Eureka Scientific, Inc., 113 Castlefern Dr., Cary, NC 25713 (United States)
10. Spitzer Science Center, California Institute of Technology, Mail Code 314-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

We present Spitzer photometric (IRAC and MIPS) and spectroscopic (IRS low resolution) observations for 314 stars in the Formation and Evolution of Planetary Systems Legacy program. These data are used to investigate the properties and evolution of circumstellar dust around solar-type stars spanning ages from approximately 3 Myr-3 Gyr. We identify 46 sources that exhibit excess infrared emission above the stellar photosphere at 24 {mu}m, and 21 sources with excesses at 70 {mu}m. Five sources with an infrared excess have characteristics of optically thick primordial disks, while the remaining sources have properties akin to debris systems. The fraction of systems exhibiting a 24 {mu}m excess greater than 10.2% above the photosphere is 15% for ages < 300 Myr and declines to 2.7% for older ages. The upper envelope to the 70 {mu}m fractional luminosity appears to decline over a similar age range. The characteristic temperature of the debris inferred from the IRS spectra range between 60 and 180 K, with evidence for the presence of cooler dust to account for the strength of the 70 {mu}m excess emission. No strong correlation is found between dust temperature and stellar age. Comparison of the observational data with disk models containing a power-law distribution of silicate grains suggests that the typical inner-disk radius is {approx}> 10 AU. Although the interpretation is not unique, the lack of excess emission shortward of 16 {mu}m and the relatively flat distribution of the 24 {mu}m excess for ages {approx}< 300 Myr is consistent with steady-state collisional models.

• OSTI ID: 21269251
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 181; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
DUSTS
LUMINOSITY
PHOTOSPHERE
STAR EVOLUTION
STARS
STEADY-STATE CONDITIONS