通过天体测量微透镜探测到的孤立质量间隙黑洞或中子星
星系天体物理
2022-07-20 v2 太阳与恒星天体物理
摘要
我们展示了从引力微透镜巡天中识别出的五个黑洞候选体的分析。我们将哈勃空间望远镜天体测量数据与地基微透镜巡天的高密度采样光变曲线用单源单透镜微透镜模型进行拟合，以测量每个透镜的质量与光度，并判断其是否为黑洞。五个目标中的一个（OGLE-2011-BLG-0462/MOA-2011-BLG-191，简称OB110462）表现出显著的>1 mas相干天体测量偏移、几乎无透镜流量，且推断透镜质量为1.6 - 4.4 。这使得OB110462成为首个通过天体测量微透镜明确发现的致密天体，其最有可能是一颗中子星或低质量黑洞。该致密天体透镜相对邻近（0.70-1.92 kpc），且横向运动缓慢，<30 km/s。OB110462在能很好拟合测光与天体测量的模型之间表现出显著张力，目前难以区分其为中子星还是黑洞。需要借助更复杂的系统几何（如双源）进行额外观测与建模，以解决该天体的谜样性质。对其余四个候选体，透镜质量均<2 ，不太可能是黑洞；其中两个很可能是白矮星或中子星。我们将这五个候选体的完整样本与银河系中黑洞数量的理论预期（~10^8）进行比较，鉴于样本量较小，结果吻合合理。
引用
@article{arxiv.2202.01903,
title = {An isolated mass gap black hole or neutron star detected with astrometric microlensing},
author = {Casey Y. Lam and Jessica R. Lu and Andrzej Udalski and Ian Bond and David P. Bennett and Jan Skowron and Przemek Mroz and Radek Poleski and Takahiro Sumi and Michal K. Szymanski and Szymon Kozlowski and Pawel Pietrukowicz and Igor Soszynski and Krzysztof Ulaczyk and Lukasz Wyrzykowski and Shota Miyazaki and Daisuke Suzuki and Naoki Koshimoto and Nicholas J. Rattenbury and Matthew W. Hosek and Fumio Abe and Richard Barry and Aparna Bhattacharya and Akihiko Fukui and Hirosane Fujii and Yuki Hirao and Yoshitaka Itow and Rintaro Kirikawa and Iona Kondo and Yutaka Matsubara and Sho Matsumoto and Yasushi Muraki and Greg Olmschenk and Clement Ranc and Arisa Okamura and Yuki Satoh and Stela Ishitani Silva and Taiga Toda and Paul J. Tristram and Aikaterini Vandorou and Hibiki Yama and Natasha S. Abrams and Shrihan Agarwal and Sam Rose and Sean K. Terry},
journal= {arXiv preprint arXiv:2202.01903},
year = {2022}
}
备注
Accepted to ApJ Letters, with corresponding ApJ Supplement. 10 page Letter (6 figures, 2 tables) + 51 page Supplement (27 figures, 20 tables, 9 appendices). Some minor updates from the refereeing process, but no change to main conclusions