GRAVITY 对船底座 η 星核心的色成像观测
太阳与恒星天体物理
2018-08-08 v1
摘要
船底座 η 星（Eta Car）是银河系中最引人入胜的亮蓝变星之一。不同波长的观测与模型表明其核心存在一个周期为 5.54 年的中心双星。2D 与 3D 辐射转移及流体动力学模拟预言了一颗具有致密且缓慢星风的主星，与次星更快且密度更低的星风相互作用。星风-星风碰撞图景表明，次星的星风穿透主星的星风，在其中形成低密度空腔，并在两星风相互作用处形成致密壁。我们旨在追踪船底座 η 星星风-星风相互作用的内层 ~5-50 au 结构，通过 BrG 以及首次通过 He I 2s-2p 谱线观测。我们使用了 VLTI 上 GRAVITY 的谱干涉观测。我们对连续谱的建模使我们估计其 FWHM 角尺寸接近 2 mas，伸长比为 1.06 ± 0.05，位置角 PA = 130 ± 20 度。我们的 CMFGEN 建模帮助我们确认应考虑次星的作用以恰当重现观测到的 BrG 与 He I 谱线。BrG 上的色成像揭示了一个东南方向的弧状特征，可能对应于沿空腔壁流动的热后激波星风。He I 2s-2p 的成像用于约束发射线区域 20 mas 的结构。He I 的观测形态表明次星负责产生该线型的电离物质。BrG 与 He I 2s-2p 图均与此前碰撞星风图景的流体动力学模型一致。未来专门的模拟结合广泛的干涉观测活动对于精炼我们对双星星风与恒星参数的约束是必要的，这最终将帮助我们预测船底座 η 星的演化路径。
引用
@article{arxiv.1808.02141,
title = {GRAVITY chromatic imaging of Eta Car's core},
author = {GRAVITY Collaboration and J. Sanchez-Bermudez and G. Weigelt and J. M. Bestenlehner and P. Kervella and W. Brandner and Th. Henning and A. Müller and G. Perrin and J. -U. Pott and M. Schöller and R. van Boekel and R. Abuter and M. Accardo and A. Amorim and N. Anugu and G. Ávila and M. Benisty and J. P. Berger and N. Blind and H. Bonnet and P. Bourget and R. Brast and A. Buron and F. Cantalloube and A. Caratti o Garatti and F. Cassaing and F. Chapron and E. Choquet and Y. Clénet and C. Collin and V. Coudé du Foresto and W. de Wit and T. de Zeeuw and C. Deen and F. Delplancke-Ströbele and R. Dembet and F. Derie and J. Dexter and G. Duvert and M. Ebert and A. Eckart and F. Eisenhauer and M. Esselborn and P. Fédou and P. J. V. Garcia and C. E. Garcia Dabo and R. Garcia Lopez and F. Gao and E. Gendron and R. Genzel and S. Gillessen and X. Haubois and M. Haug and F. Haussmann and S. Hippler and M. Horrobin and A. Huber and Z. Hubert and N. Hubin and C. A. Hummel and G. Jakob and L. Jochum and L. Jocou and M. Karl and A. Kaufer and S. Kellner and S. Kendrew and L. Kern and M. Kiekebusch and R. Klein and J. Kolb and M. Kulas and S. Lacour and V. Lapeyrère and B. Lazareff and J. -B. Le Bouquin and P. Léna and R. Lenzen and S. Levêque and M. Lippa and Y. Magnard and L. Mehrgan and M. Mellein and A. Mérand and J. Moreno-Ventas and T. Moulin and E. Müller and F. Müller and U. Neumann and S. Oberti and T. Ott and L. Pallanca and J. Panduro and L. Pasquini and T. Paumard and I. Percheron and K. Perraut and P. -O. Petrucci and A. Pflüger and O. Pfuhl and T. P. Duc and P. M. Plewa and D. Popovic and S. Rabien and A. Ramirez and J. Ramos and C. Rau and M. Riquelme and G. Rodríguez-Coira and R. -R. Rohloff and A. Rosales and G. Rousset and S. Scheithauer and N. Schuhler and J. Spyromilio and O. Straub and C. Straubmeier and E. Sturm and M. Suarez and K. R. W. Tristram and N. Ventura and F. Vincent and I. Waisberg and I. Wank and F. Widmann and E. Wieprecht and M. Wiest and E. Wiezorrek and M. Wittkowski and J. Woillez and B. Wolff and S. Yazici and D. Ziegler and G. Zins},
journal= {arXiv preprint arXiv:1808.02141},
year = {2018}
}
备注
32 pages, 27 figures (14 in the main body, 13 in the appendices), accepted for publication in AA