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arXiv 0905.1487astro-ph.SR
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在牧夫座和首视巡天中,斯皮策24 μ m亮星系星的过剩

Spitzer 24 um Excesses for Bright Galactic Stars in Bootes and First Look Survey Fields

L. R. Hovhannisyan, A. M. Mickaelian, D. W. Weedman, E. Le Floc'h, J. R. Houck, B. T. Soifer, K. Brand, A. Dey, B. T. Jannuzi

摘要:

光学明亮的银河系恒星(V < 13等),fv(24微米)> 1 mJy,在斯皮策中红外巡天中被识别,在NOAO深宽视场巡天的牧夫座视场中,在8.2平方度范围内,在第一次巡天(FLS)的5.5平方度范围内。在牧夫座星系中识别了128颗恒星,在FLS中识别了140颗恒星,并给出了它们的测光结果。(K-[24])颜色是用2 MASS巡天的K星等来确定的,目的是寻找比恒星光球层光度高出24 μ m的恒星。在268颗恒星的组合样本中,有141颗恒星的光谱类型为F、G或K,其中17颗恒星的超差为24 μ m,(K-[24])> 0.2等。使用自行得出的绝对星等极限,至少有8颗超差的FGK恒星是主序星,根据视星等分布估计,这17颗恒星都是主序星。这些估计导致的结论是,在这些样本中的主序FGK场的恒星有9%和17%之间的24 μ m的红外线过剩。这一结果在统计学上类似于斯皮策以前对更明亮的主序星进行有针对性的观测时发现的具有碎片盘的恒星比例。

英文摘要:

Optically bright Galactic stars (V < 13 mag) having fv(24 um) > 1 mJy are identified in Spitzer mid-infrared surveys within 8.2 square degrees for the Bootes field of the NOAO Deep Wide-Field Survey and within 5.5 square degrees for the First Look Survey (FLS). 128 stars are identified in Bootes and 140 in the FLS, and their photometry is given. (K-[24]) colors are determined using K magnitudes from the 2MASS survey for all stars in order to search for excess 24 um luminosity compared to that arising from the stellar photosphere. Of the combined sample of 268 stars, 141 are of spectral types F, G, or K, and 17 of these 141 stars have 24 um excesses with (K-[24]) > 0.2 mag. Using limits on absolute magnitude derived from proper motions, at least 8 of the FGK stars with excesses are main sequence stars, and estimates derived from the distribution of apparent magnitudes indicate that all 17 are main sequence stars. These estimates lead to the conclusion that between 9% and 17% of the main sequence FGK field stars in these samples have 24 um infrared excesses. This result is statistically similar to the fraction of stars with debris disks found among previous Spitzer targeted observations of much brighter, main sequence field stars.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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