MOA-2011-BLG-293Lb: A TEST OF PURE SURVEY MICROLENSING PLANET DETECTIONS-猫眼课题宝

DOI：

10.1088/0004-637x/755/2/102

发表时间：

2012-01

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

J. Yee;Y. Shvartzvald;A. Gal-yam;I. Bond;A. Udalski;S. Kozłowski;C. Han;A. Gould;J. Skowron;D. Suzuki;F. Abe;David P. Bennett;C. Botzler;P. Chote;M. Freeman;A. Fukui;K. Furusawa;Y. Itow;S. Kobara;C. Ling;K. Masuda;Y. Matsubara;N. Miyake;Yasushi Muraki;Kantaro Ohmori;K. Ohnishi;N. Rattenbury;T. Saito;D. Sullivan;T. Sumi;K. Suzuki;W. Sweatman;S. Takino;P. Tristram;K. Wada;M. Szymański;M. Kubiak;G. Pietrzyński;G. Pietrzyński;I. Soszyński;R. Poleski;K. Ulaczyk;Ł. Wyrzykowski;Ł. Wyrzykowski;P. Pietrukowicz;William H. Allen;L. Almeida;V. Batista;M. Bos;G. Christie;D. Depoy;S. Dong;Jack D. Drummond;I. Finkelman;B. Gaudi;E. Gorbikov;C. Henderson;D. Higgins;Francisco Jablonski;S. Kaspi;I. Manulis;D. Maoz;J. Mccormick;D. McGregor;L. Monard;D. Moorhouse;J. A. Muñoz;T. Natusch;H. Ngan;E. Ofek;R. Pogge;R. Santallo;Thiam-Guan Tan;G. Thornley;I. Shin;J.-Y. Choi;S.-Y. Park;C.‐U. Lee;J. Koo

由于大尺寸、宽视场相机的发展，微透镜巡天现在能够以足够的节奏监测数百万颗恒星，以探测行星。这些新发现将涵盖所有的重要性级别，包括行星信号太小而无法从噪音中区分出来。目前，我们还不知道探测行星的门槛在哪里。MOA-2011-BLG-293 Lb是第一颗从新的调查中公布的行星，它也有大量的后续观测。这颗行星在巡天+后续数据（Δχ2 <$5400）中被稳健地探测到。行星/宿主质量比为q =（5.3 ± 0.2）× 10−3。最佳拟合投影间距为s = 0.548 ± 0.005爱因斯坦半径。然而，由于s Partics −1的简并性，s−1的投影分离在Δχ2 = 3时仅略微不利。宿主质量的贝叶斯估计值为ML = 0.43+0.27− 0.17 M，与透镜通量上限相比，ML的上限小于1.2 M。因此，行星的质量为mp = 2.4+1.5− 0.9 MJup，物理上的投影距离为r = 1.0 Au或r = 3.4 Au。我们表明，调查数据单独预测这个解决方案，并能够描述行星，但Δχ2是小得多（Δχ2 <$500）比后续数据。仅调查数据的Δχ2就小于任何其他安全探测到的行星。这一事件提出了一种探测探测阈值的方法，通过分析MOA-2011-BLG-293等事件的大样本，这些事件既有后续数据，也有高节奏的调查数据，为解释纯调查微透镜数据提供指导。

Because of the development of large-format, wide-field cameras, microlensing surveys are now able to monitor millions of stars with sufficient cadence to detect planets. These new discoveries will span the full range of significance levels including planetary signals too small to be distinguished from the noise. At present, we do not understand where the threshold is for detecting planets. MOA-2011-BLG-293Lb is the first planet to be published from the new surveys, and it also has substantial follow-up observations. This planet is robustly detected in survey+follow-up data (Δχ2 ∼ 5400). The planet/host mass ratio is q = (5.3 ± 0.2) × 10−3. The best-fit projected separation is s = 0.548 ± 0.005 Einstein radii. However, due to the s↔s−1 degeneracy, projected separations of s−1 are only marginally disfavored at Δχ2 = 3. A Bayesian estimate of the host mass gives ML = 0.43+0.27− 0.17 M☉, with a sharp upper limit of ML < 1.2 M☉ from upper limits on the lens flux. Hence, the planet mass is mp = 2.4+1.5− 0.9 MJup, and the physical projected separation is either r⊥ ≃ 1.0 AU or r⊥ ≃ 3.4 AU. We show that survey data alone predict this solution and are able to characterize the planet, but the Δχ2 is much smaller (Δχ2 ∼ 500) than with the follow-up data. The Δχ2 for the survey data alone is smaller than for any other securely detected planet. This event suggests a means to probe the detection threshold, by analyzing a large sample of events like MOA-2011-BLG-293, which have both follow-up data and high-cadence survey data, to provide a guide for the interpretation of pure survey microlensing data.

MOA-2011-BLG-293Lb: A TEST OF PURE SURVEY MICROLENSING PLANET DETECTIONS

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