Distance to the Low-velocity Cloud in the Direction of the High-velocity Compact Cloud CO–0.40–0.22
Distance to the Low-velocity Cloud in the Direction of the High-velocity Compact Cloud CO–0.40–0.22
复制标题
高速致密云方向上到低速云的距离 CO–0.40–0.22
DOI：
10.3847/1538-4357/aa67f9
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
T. Oka
中科院分区：
文献类型：
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作者：
Y. Iwata;Haruka Kato;D. Sakai;T. Oka
CO-0.40-0.22是一种特殊的分子云，结构紧凑，速度宽度非常宽。它被发现在我们银河系的中央分子带（CMZ）。在这个方向上，有另一个云，它有一个速度较低的H2O脉泽斑。与这种低速云的碰撞可能导致CO-0.40-0.22的宽速度宽度。我们利用VERA进行了相位参考甚长基线干涉测量（VLBI）天文测量，检测到低速云中H2O脉射斑的年视差为0.33±0.14 mas，对应于与太阳的距离。这意味着低速云位于CMZ近侧的银盘上。
CO–0.40–0.22 is a peculiar molecular cloud that is compact and has an extraordinary broad velocity width. It is found in the central molecular zone (CMZ) of our Galaxy. In this direction, there is another cloud with an H2O maser spot at a lower velocity. A collision with this low-velocity cloud could be responsible for the broad velocity width of CO–0.40–0.22. We performed phase-referencing very long baseline interferometry (VLBI) astrometry with VERA and detected the annual parallax of the H2O maser spot in the low-velocity cloud to be 0.33 ± 0.14 mas, which corresponds to a distance of from the Sun. This implies that the low-velocity cloud is located in the Galactic disk on the near side of the CMZ.