利用 VERITAS 天文台进行恒星强度干涉测量获取 $\beta$ UMa 角直径
太阳与恒星天体物理
2024-01-04 v1 天体物理仪器与方法
摘要
我们利用 VERITAS 成像大气切伦科夫望远镜(IACT)阵列，通过恒星强度干涉测量(SII)首次在可见光波段获得了 UMa 的角直径测量值，并独立约束了其临边昏暗角直径。大熊座移动星群的年龄已通过其成员星的年龄进行评估，其中包括核成员星 Merak( UMa)，一颗 A1 型亚巨星，方法是将有效温度和光度约束与恒星演化模型轨迹进行比较。此前在近红外(CHARA Array， mas)和中红外(Keck Nuller， mas)波段对 UMa 的干涉临边昏暗角直径测量，结合测得的视差和热辐射流量，已对其有效温度进行了约束。本文介绍了当前 VERITAS-SII 的观测和分析流程，从相关函数导出平方可见度。我们拟合所得平方可见度，利用与 UMa 光学波段光谱良好匹配的恒星大气模型生成的合成可见度，得到临边昏暗角直径为 (sys) mas。VERITAS-SII 临边昏暗角直径给出的有效温度为 K，与紫外分光光度法一致，并利用 MESA 等时线与恒星轨迹(MIST)得出年龄为 Myr。该年龄与 CHARA Array 角直径给出的 Myr 一致。
引用
@article{arxiv.2401.01853,
title = {An Angular Diameter Measurement of $\beta$ UMa via Stellar Intensity Interferometry with the VERITAS Observatory},
author = {A. Acharyya and J. P. Aufdenberg and P. Bangale and J. T. Bartkoske and P. Batista and W. Benbow and A. J. Chromey and J. D. Davis and Q. Feng and G. M. Foote and A. Furniss and W. Hanlon and C. E. Hinrichs and J. Holder and W. Jin and P. Kaaret and M. Kertzman and D. Kieda and T. K. Kleiner and N. Korzoun and T. LeBohec and M. A. Lisa and M. Lundy and N. Matthews and C. E McGrath and M. J. Millard and P. Moriarty and S. Nikkhah and S. O'Brien and R. A. Ong and M. Pohl and E. Pueschel and J. Quinn and P. L. Rabinowitz and K. Ragan and E. Roache and J. G. Rose and J. L. Sackrider and I. Sadeh and L. Saha and G. H. Sembroski and R. Shang and D. Tak and M. Ticoras and J. V. Tucci and S. L. Wong and The VERITAS Collaboration},
journal= {arXiv preprint arXiv:2401.01853},
year = {2024}
}