寻找具有Pan-STARRS1 +2 MASS + WISE的高自行T矮星
A Search for High Proper Motion T Dwarfs with Pan-STARRS1 + 2MASS + WISE
摘要：
我们已经搜索了8200平方米。degs的高自行（~0.5-2.7”/年）T矮星的第一个历元数据相结合的泛星1（PS1）3-Pi调查，2 MASS全天点源目录，和WISE初步数据发布。我们确定了两个具有T矮星特征的非常红（W1-W2）颜色的高自行天体，其中一个是已知的T7.5矮星GJ 570 D。另一个天体（PSO J043.5+02 = WISEP J 0254 +0223）的近红外光谱显示光谱类型为T8，导致光度距离为7.2+/-0.7 pc。PSO J043.5+02的自行速度为2.56”/yr，是T型矮星中第二高的自行速度，对应的切向速度为87+/-8 km/s。根据贝桑松星系模型，这个速度表明它的星系成员可能是在薄盘中，厚盘是不太可能的。这种隶属关系是符合近红外光谱，它指向一个表面重力（年龄）和金属丰度典型的现场人口。我们结合了2 MASS、SDSS、WISE和PS1天体测量，得出了171+/-45 mas（5.8{+2.0}{-1.2} pc）的初步视差，这是第一次使用PS1数据进行这样的测量。PSO J 043 +02的接近度和亮度将有助于未来对其大气层、变异性、多样性、距离和运动学的表征。从我们搜索的候选者的适度数量表明，直接（~10 pc）太阳附近不包含一个大水库的未发现的T矮星早于约T8。
英文摘要：
We have searched ~8200 sq. degs for high proper motion (~0.5-2.7"/year) T dwarfs by combining first-epoch data from the Pan-STARRS1 (PS1) 3-Pi Survey, the 2MASS All-Sky Point Source Catalog, and the WISE Preliminary Data Release. We identified two high proper motion objects with the very red (W1-W2) colors characteristic of T dwarfs, one being the known T7.5 dwarf GJ 570D. Near-IR spectroscopy of the other object (PSO J043.5+02 = WISEP J0254+0223) reveals a spectral type of T8, leading to a photometric distance of 7.2+/-0.7 pc. The 2.56"/yr proper motion of PSO J043.5+02 is the second highest among field T dwarfs, corresponding to an tangential velocity of 87+/-8 km/s. According to the Besancon galaxy model, this velocity indicates its galactic membership is probably in the thin disk, with the thick disk an unlikely possibility. Such membership is in accord with the near-IR spectrum, which points to a surface gravity (age) and metallicity typical of the field population. We combine 2MASS, SDSS, WISE, and PS1 astrometry to derive a preliminary parallax of 171+/-45 mas (5.8{+2.0}{-1.2} pc), the first such measurement using PS1 data. The proximity and brightness of PSO J043+02 will facilitate future characterization of its atmosphere, variability, multiplicity, distance, and kinematics. The modest number of candidates from our search suggests that the immediate (~10 pc) solar neighborhood does not contain a large reservoir of undiscovered T dwarfs earlier than about T8.
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。
