The Gemini Deep Planet Survey
The Gemini Deep Planet Survey
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双子座深行星巡天
DOI：
10.1086/522826
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
R. Racine
中科院分区：
文献类型：
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作者：
D. Lafreniére;R. Doyon;C. Marois;D. Nadeau;B. Oppenheimer;P. Roche;F. Rigaut;J. Graham;R. Jayawardhana;D. Johnstone;P. Kalas;B. Macintosh;R. Racine
我们提出了双子座深行星调查的结果，近红外自适应光学搜索巨行星和棕矮星周围的85个附近的年轻恒星。观测是在双子座北望远镜上用牛郎星自适应光学系统获得的，角微分成像被用来抑制中心星星的斑点噪声。通常情况下，观测对超过0.5“的角间距敏感，在1.6 μm处的星等差的5 σ对比度灵敏度为9.5在0.5”处，12.9在1“处，15.0在2”处，16.5在5“处。这些灵敏度足以探测到质量超过2 MJ的行星，其距离在典型目标周围的40-200 Au范围内。对54颗候选恒星中的48颗恒星的第二历元观测证实，所有候选恒星都是不相关的背景恒星。对调查结果进行了详细的统计分析。假设行星质量分布为dn/dm m-1.2，半长轴分布为dn/da a-1，则在10-25 Au、25-50 Au和50-250 Au范围内，至少有一颗质量为0.5-13 MJ的行星的恒星比例的95%可信上限分别为0.28、0.13和0.093;该结果弱依赖于半长轴分布幂律指数。在不考虑质量和长半轴分布假设的情况下，拥有至少一颗长半轴在25-250 Au范围内的棕矮星伴星的恒星比例的95%可信区间为0.019。作为这次巡天的一部分，我们首次将HD 14802、HD 166181和HD 213845分解成双星。
We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around 85 nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope, and angular differential imaging was used to suppress the speckle noise of the central star. Typically, the observations are sensitive to angular separations beyond 0.5'' with 5 σ contrast sensitivities in magnitude difference at 1.6 μm of 9.5 at 0.5'', 12.9 at 1'', 15.0 at 2'', and 16.5 at 5''. These sensitivities are sufficient to detect planets more massive than 2 MJ with a projected separation in the range 40-200 AU around a typical target. Second-epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated background stars. A detailed statistical analysis of the survey results is presented. Assuming a planet mass distribution dn/dm ∝ m-1.2 and a semimajor-axis distribution dn/da ∝ a-1, the 95% credible upper limits on the fraction of stars with at least one planet of mass 0.5-13 MJ are 0.28 for the range 10-25 AU, 0.13 for 25-50 AU, and 0.093 for 50-250 AU; this result is weakly dependent on the semimajor-axis distribution power-law index. The 95% credible interval for the fraction of stars with at least one brown dwarf companion having a semimajor axis in the range 25-250 AU is 0.019, irrespective of any assumption on the mass and semimajor-axis distributions. The observations made as part of this survey have resolved the stars HD 14802, HD 166181, and HD 213845 into binaries for the first time.