<p> Debris disk candidates around nearby stars were detected with the <i> Spitzer Space Telescope</i> using the Multiband Imaging Photometer (MIPS) at 24μm (MIPS24) and 70μm (MIPS70). A survey sample of 978 stars within 25pc of the Sun was observed with MIPS24, with 438 stars solely observed with MIPS70. Candidates were defined as target stars with excess infrared emission above the stellar photospheric emission at both 3σ and 5σ levels. At 24μm, debris disks were identied around 262 stars, yielding a detection frequency of 26.8% at the 3σ level. A detection rate of 22.1% is deduced from 216 stars at the 5σ level. The detection frequency at 24μm shows a decreasing trend with late spectral types. A detection rate of 26.5% is implied by 128 MIPS70 candidates at the 3σ level, and 11.8% is revealed by 57 candidates at the 5σ level. At 70μm, our 3σ and 5σ detections correspond to fractional luminosities of 10<sup>-3.</sup>8 and 10<sup>-3.4</sup>, respectively. Both detection rates increase with later spectral types. </p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:1537816 |
| Date | 19 June 2013 |
| Creators | Wang, Luqian |
| Publisher | Northern Arizona University |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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