OGLE-2017-BLG-1434Lb：第八颗 q < 1*10^-4 质量比微透镜行星确认行星质量比函数的转折
地球与行星天体物理
2018-10-24 v1
摘要
我们报告发现一颗寒冷的超级地球行星（m_p=4.4 +/- 0.5 M_Earth）环绕一颗低质量（M=0.23 +/- 0.03 M_Sun）M矮星，投影间距 a_perp = 1.18 +/- 0.10 AU，即约为雪线的1.9倍。对于一颗微透镜行星而言，该系统相当邻近，D_Lens = 0.86 +/- 0.09 kpc。事实上，正是较大的透镜-源相对视差 pi_rel=1.0 mas（结合低质量M）产生了较大且因而被良好测量的“微透镜视差”，使得这些精确测量成为可能。OGLE-2017-BLG-1434Lb是第八颗行星-宿主质量比 q < 1 * 10^-4 的微透镜行星。我们对这八颗中的七颗应用一种新的行星探测灵敏度方法（其为“V/V_max”的变体）以推导该区间内的质量比函数。我们发现 dN/d(ln q) ~ q^p，其中 p = 1.05 (+0.78,-0.68)，这确认了Suzuki等人相对于在较高质量比 q >~ 2 * 10^-4 处相反符号幂律 n = -0.93 +/- 0.13 所发现的质量函数“转折”。我们将我们的结果与Suzuki等人的结果结合得到 p = 0.73 (+0.42,-0.34)。
引用
@article{arxiv.1802.02582,
title = {OGLE-2017-BLG-1434Lb: Eighth q < 1 * 10^-4 Mass-Ratio Microlens Planet Confirms Turnover in Planet Mass-Ratio Function},
author = {A. Udalski and Y. -H. Ryu and S. Sajadian and A. Gould and P. Mróz and R. Poleski and M. K. Szymański and J. Skowron and I. Soszyński and S. Kozłowski and P. Pietrukowicz and K. Ulaczyk and M. Pawlak and K. Rybicki and P. Iwanek and M. D. Albrow and S. -J. Chung and C. Han and K. -H. Hwang and Y. K. Jung and I. -G. Shin and Y. Shvartzvald and J. C. Yee and W. Zang and W. Zhu and S. -M. Cha and D. -J. Kim and H. -W. Kim and S. -L. Kim and C. -U. Lee and D. -J. Lee and Y. Lee and B. -G. Park and R. W. Pogge and V. Bozza and M. Dominik and C. Helling and M. Hundertmark and U. G. Jørgensen and P. Longa-Peña and S. Lowry and M. Burgdorf and J. Campbell-White and S. Ciceri and D. Evans and R. Figuera Jaimes and Y. I. Fujii and L. K. Haikala and T. Henning and T. C. Hinse and L. Mancini and N. Peixinho and S. Rahvar and M. Rabus and J. Skottfelt and C. Snodgrass and J. Southworth and C. von Essen},
journal= {arXiv preprint arXiv:1802.02582},
year = {2018}
}
备注
53 pages, 16 figures