利用GRAVITY探测SgrA*附近的暗弱恒星
星系天体物理
2021-02-26 v2 天体物理仪器与方法
摘要
原则上，位于银河系中心的超大质量黑洞的自旋可以通过精确测量比S2更靠近SgrA*的恒星轨道来测量，S2的轨道最近提供了引力红移和史瓦西进动的测量。结合甚大望远镜（VLT）四台8米望远镜的GRAVITY近红外干涉仪提供了2-4毫角秒的空间分辨率，打破了单台8-10米望远镜自适应光学辅助成像的混淆极限。我们利用GRAVITY在2019年六个月期间观测了SgrA*，并采用射电天文学中发展的干涉重建方法来搜索SgrA*附近的暗弱天体。这揭示了一颗在K波段星等18.9、位于SgrA* 30毫角秒内缓慢移动的恒星。该恒星的位置和自行与此前已知的恒星S62一致，S62物理距离大得多，但在投影上靠近SgrA*。2019年8月和9月的观测轻易探测到了S29，其K波段星等16.6，距SgrA*约130毫角秒。GRAVITY的计划升级以及定标的进一步改进，有望发现K波段星等暗于19的恒星。
引用
@article{arxiv.2011.03058,
title = {Detection of faint stars near SgrA* with GRAVITY},
author = {GRAVITY Collaboration and R. Abuter and A. Amorim and M. Bauböck and J. P. Berger and H. Bonnet and W. Brandner and Y. Clénet and Y. Dallilar and R. Davies and P. T. de Zeeuw and J. Dexter and A. Drescher and F. Eisenhauer and N. M. Förster Schreiber and P. Garcia and F. Gao and E. Gendron and R. Genzel and S. Gillessen and M. Habibi and X. Haubois and G. Heißel and T. Henning and S. Hippler and M. Horrobin and A. Jiménez-Rosales and L. Jochum and L. Jocou and A. Kaufer and P. Kervella and S. Lacour and V. Lapeyrère and J. -B. Le Bouquin and P. Léna and D. Lutz and M. Nowak and T. Ott and T. Paumard and K. Perraut and G. Perrin and O. Pfuhl and S. Rabien and G. Rodríguez-Coira and J. Shangguan and T. Shimizu and S. Scheithauer and J. Stadler and O. Straub and C. Straubmeier and E. Sturm and L. J. Tacconi and F. Vincent and S. von Fellenberg and I. Waisberg and F. Widmann and E. Wieprecht and E. Wiezorrek and J. Woillez and S. Yazici and G. Zins},
journal= {arXiv preprint arXiv:2011.03058},
year = {2021}
}
备注
12 pages, 11 figures, published in A&A. Here we updated Fig. 1 with the latest motions laws of the S-stars as obtained from VLT/NACO observations until end 2019