在VLT和MMT上用SDI对45颗近距离年轻恒星周围的太阳系外行星的成像巡天
An Imaging Survey for Extrasolar Planets around 45 Close, Young Stars with SDI at the VLT and MMT
摘要：
我们提出的调查结果的45个年轻的（<2.5亿年），接近（<50 pc）的恒星与同步差分成像仪（SDI）实施的VLT和MMT的太阳系外行星的直接检测。作为调查的一部分，我们总共观察到54个物体，其中45个是近距离的年轻恒星，2个是稍微远一点的（<150 pc），非常年轻（<1000万年）的恒星，3个是已知径向速度行星的恒星，4个是较老的，非常接近（<20 pc）的太阳类似物。我们的SDI设备使用双Wollaston棱镜和四倍滤波器，在冷棕矮星和气体巨行星光谱中发现的1.62 um甲烷吸收带头周围的3个波长同时拍摄图像。在我们的VLT数据中，我们在45%的目标上实现了H波段对比度> 10等（5 sigma），距离主星0.5”，在80%的目标上实现了H波段对比度> 9等，距离0.5“。有了这种程度的衰减，我们应该能够成像（5西格玛检测）一个5 M_{Jup}行星15天文单位从一个7000万年K1恒星在15 pc或一个5 M_{Jup}行星2天文单位从一个1200万年M恒星在10 pc。我们相信，我们的SDI图像是有史以来从地面或太空拍摄的距离恒星<1“的富含甲烷的同伴的最高对比度天文图像。对于最好的20颗巡天恒星，我们在半长轴为20-40 AU的6-10颗M_Jup行星上获得了50%的5 σ完整性。因此，我们的完整性水平足以显著测试理论行星分布。从我们的调查零结果，我们可以排除（在98%置信度/2.0 sigma水平）使用行星分布的模型行星种群，其中N（a）$\propto$恒定到45 AU的距离（进一步的模型假设在本文中讨论）。
英文摘要：
We present the results of a survey of 45 young (<250 Myr), close (<50 pc) stars with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT for the direct detection of extrasolar planets. As part of the survey, we observed 54 objects total, of which 45 were close, young stars, 2 were somewhat more distant (<150 pc), very young (<10 Myr) stars, 3 were stars with known radial velocity planets, and 4 were older, very nearby (<20 pc) solar analogues. Our SDI devices use a double Wollaston prism and a quad filter to take images simultaneously at 3 wavelengths surrounding the 1.62 um methane absorption bandhead found in the spectrum of cool brown dwarfs and gas giant planets. In our VLT data, we achieved H band contrasts > 10 mag (5 sigma) at a separation of 0.5" from the primary star on 45% of our targets and H band contrasts of > 9 mag at a separation of 0.5'' on 80% of our targets. With this degree of attenuation, we should be able to image (5sigma detection) a 5 M_{Jup} planet 15 AU from a 70 Myr K1 star at 15 pc or a 5 M_{Jup} planet at 2 AU from a 12 Myr M star at 10 pc. We believe that our SDI images are the highest contrast astronomical images ever made from ground or space for methane rich companions <1'' from their star. For the best 20 of our survey stars, we attained 50% 5 sigma completeness for 6-10 M_Jup planets at semi-major axes of 20-40 AU. Thus, our completeness levels are sufficient to significantly test theoretical planet distributions. From our survey null result, we can rule out (at the 98% confidence/2.0sigma level) a model planet population using a planet distribution where N(a) $\propto$ constant out to a distance of 45 AU (further model assumptions discussed within).
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。
