Be/X射线双星MWC 656的H_alpha观测
H_alpha observations of the Be/X-ray binary MWC 656
- Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences（保加利亚科学院天文台与国家天文研究所）
- Department of Applied Physics, Technical University of Sofia（索非亚理工大学应用物理系）
- Department of Physics and Astronomy, Shumen University "Episkop Konstantin Preslavski"（舒门大学“主教康斯坦丁·普雷斯拉夫斯基”物理与天文学系）
- Departamento de Física, Escuela Politécnica Superior de Jaén, Universidad de Jaén（哈恩大学哈恩高等理工学院物理系）
- Astrophysics Research Institute, Liverpool John Moores University（利物浦约翰摩尔斯大学天体物理研究所）
- Office of the Vice Chancellor, Botswana International University of Science and Technology（博茨瓦纳国际科学与技术大学副校长办公室）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
基于2021-2026年高分辨率光谱，发现Be/X射线双星MWC 656的H_alpha发射线存在60.43天轨道调制，估算轨道偏心率0.11，伴星质量约5太阳质量，可能为恒星质量黑洞或剥离恒星。
AI中文摘要：
背景。MWC 656是一个Be/X射线双星，被识别为发射线天体、X射线和射电源，可能是一个弱的伽马射线源，其伴星成分性质神秘。\n目的。本文旨在研究H_alpha发射线的轨道调制、盘截断，并评估双星参数。\n方法。在2021-2026年期间，我们获得了MWC 656的高分辨率（30000）光学光谱，并与已发表的数据一起分析。\n结果。我们发现H_alpha发射线存在轨道调制，周期P_orb = 60.43 ± 0.03天。假设Be星周盘被伴星截断，我们估算轨道偏心率e = 0.11 ± 0.01，半长轴a = 160 R_sun，双星质量M_1 + M_2 = 15.1 M_sun。\n结论。H_alpha发射的轨道调制表明：（1）在该天体中，我们观察到一种新型的Be盘周期性变化；（2）轨道是轻度偏心的；（3）MWC 656的伴星是一个质量约为5 M_sun的大质量天体，比中子星更重——可能是一个恒星质量黑洞或一颗大质量的剥离恒星。
英文摘要：
Context. MWC 656 is a Be/X-ray binary identified as an emission-line object, X-ray and radio source and might be a weak gamma-ray source, harbouring an enigmatic secondary component. Aims. Our aim here is to study the orbital modulation of the H-alpha emission line, disc truncation and to evaluate the binary parameters. Methods. During the period 2021-2026, we obtained high resolution (30000) optical spectra of MWC 656 and analysed them together with the published data. Results. We find an orbital modulation of the H_alpha emission line with period P orb = 60.43 +/- 0.03 d. By assuming that the Be circumstellar disc is truncated by the companion, we estimate orbital eccentricity e = 0.11 +/- 0.01, semimajor axis a=160 R_sun, and mass of the binary M_1 + M_2 = 15.1 M_sun. Conclusions. The orbital modulation of the H_alpha emission suggests that (1) in this object we have a new type of cyclic variability of a Be disc; (2) the orbit is mildly eccentric; and (3) the secondary component of MWC 656 is a massive object 5 M_sun, more massive than the neutron stars - a stellar-mass black hole or a massive stripped star.
