论文标题
黑洞瞬态最大J1820+070中的二进制质量比
The binary mass ratio in the black hole transient MAXI J1820+070
论文作者
论文摘要
我们介绍了与黑洞X射线瞬态最大J1820+070（= Asassn-18ey）的中间分辨率光谱，该光谱在10.4 m Gran望远镜加拿大canarias上使用Osiris光谱仪获得。观察结果是用靠近静态状态的源和2019年8月重新活动发作之前进行的。我们利用这些数据和K-type矮人模板采用了相同的仪器配置，以测量供体星的投影旋转速度。 We find $v_{rot} \sin i = 84 \pm 5$ km s$^{-1}$ ($1\!-\!σ$), which implies a donor to black-hole mass ratio $q = {M_2}/{M_1} = 0.072 \pm 0.012$ for the case of a tidally locked and Roche-lobe filling donor star.恒星组件的派生动力质量为$ m_1 =（5.95 \ pm 0.22）\ sin ^{ - 3} i $ $ $ m_ \ odot $和$ m_2 =（0.43 \ pm 0.08） $ Q $的使用，结合了光谱时的积聚磁盘大小的估计，使我们能够将以前的轨道倾斜限制修改为$ 66^{\ circ} <i <81^{\ circ} $。这些值导致$ 5.73 <m_1（m_ \ odot）<8.34 $和$ 0.28 <m_2（m_ \ odot）<0.77 $的质量限制95％。取而代之的是采用$ 63 \ pm 3^{\ circ} $作为二进制倾斜时的定向角，导致$ m_1 = 8.48^{+0.79} _ { - 0.72} m_ \ odot $和$ M_2 = 0.61 = 0.61^{+0.13} {+0.13} {+0.13} ________________________12} M_ （$ 1 \！ - \！σ$）。
We present intermediate resolution spectroscopy of the optical counterpart to the black hole X-ray transient MAXI J1820+070 (=ASASSN-18ey) obtained with the OSIRIS spectrograph on the 10.4-m Gran Telescopio Canarias. The observations were performed with the source close to the quiescent state and before the onset of renewed activity in August 2019. We make use of these data and K-type dwarf templates taken with the same instrumental configuration to measure the projected rotational velocity of the donor star. We find $v_{rot} \sin i = 84 \pm 5$ km s$^{-1}$ ($1\!-\!σ$), which implies a donor to black-hole mass ratio $q = {M_2}/{M_1} = 0.072 \pm 0.012$ for the case of a tidally locked and Roche-lobe filling donor star. The derived dynamical masses for the stellar components are $M_1 = (5.95 \pm 0.22)\sin ^{-3}i$ $M_\odot$ and $M_2 = (0.43 \pm 0.08) \sin^{-3}i$ $M_\odot$. The use of $q$, combined with estimates of the accretion disk size at the time of the optical spectroscopy, allows us to revise our previous orbital inclination constraints to $66^{\circ} < i < 81^{\circ}$. These values lead to 95% confidence level limits on the masses of $5.73 <M_1(M_\odot) < 8.34$ and $0.28 < M_2(M_\odot) < 0.77$. Adopting instead the $63 \pm 3^{\circ}$ orientation angle of the radio jet as the binary inclination leads to $M_1 = 8.48^{+0.79}_{-0.72} M_\odot$ and $M_2 = 0.61^{+0.13}_{-0.12} M_\odot$ ($1\!-\!σ$).
