Emission-Line Eclipse Mapping of Velocity Fields in a Dwarf-Nova Accretion Disk
Emission-Line Eclipse Mapping of Velocity Fields in a Dwarf-Nova Accretion Disk
复制标题
矮新星吸积盘中速度场的发射线日食映射
DOI：
10.1093/pasj/54.3.463
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Y. I. F. T. Physics
中科院分区：
文献类型：
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作者：
M. Makita;Shin Mineshige Department of Astronomy;K. University;Y. I. F. T. Physics
本文提出了一种新的吸积盘速度场的位置空间映射方法——发射在线日食映射。静止的矮新星由于其盘的旋转，通常呈现双峰的发射谱线。由于在食星系统中，具有不同视距速度的盘的一部分会先后被伴星遮挡，因此它们呈现出随时间变化的线轮廓。假设开普勒旋转场（v＿ \phi\propto r^(-1/2)，其中r为距圆盘中心的距离）和j \propto r^（-3/2）的发射率分布，我们计算了发射线轮廓的时间变化。然后，我们将通常的日食映射技术应用于穿过线中心的每12-24波长的光曲线，以相同的视线速度绘制该区域。对于高视距速度，重建图像通常表现为“两只眼睛”模式，我们可以在轴对称圆盘的假设下恢复关系v＿ \phi\propto d^(-1/2)，其中d是两只“眼睛”之间的距离。我们将能够探测开普勒旋转定律，这是许多圆盘模型采用的最基本假设，通过8米级望远镜的高速光谱观测。
We propose a new method, emission-line eclipse mapping, to map the velocity fields of an accretion disk in position space. Quiescent dwarf novae usually exhibit double-peaked emission line profiles because of disk rotation. Since a part of the disk having a different line-of-sight velocity is successively obscured by a companion in eclipsing systems, they show time-varying line profiles. We calculate time changes of the emission line profiles, assuming Keplerian rotation fields (v_\phi\propto r^(-1/2) with r being the distance from the disk center) and the emissivity distribution of j \propto r^(-3/2). We, then, apply the usual eclipse mapping technique to the light curves at each of 12-24 wavelengths across the line center to map the region with the same line-of-sight velocity. The reconstructed images typically exhibit a `two-eye' pattern for high line-of-sight velocities and we can recover the relation, v_\phi \propto d^(-1/2), on the assumption of the axisymmetric disk, where d is the separation between the two `eyes'. We will be able to probe the Keplerian rotation law, the most fundamental assumption adopted in many disk models, by high-speed spectroscopic observations with 8-m class telescopes.