H I in the Field of the Dwarf Spheroidal/Irregular Galaxy Phoenix
H I in the Field of the Dwarf Spheroidal/Irregular Galaxy Phoenix
复制标题
矮球体/不规则星系凤凰座领域的 H I
DOI：
10.1086/301021
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
T. Oosterloo
中科院分区：
文献类型：
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作者：
J. St;C. Carignan;Ste´phanie Coˆte;T. Oosterloo
新的结果提出了马赛克映射的H I在本群矮星系凤凰领域。这些观测是由澳大利亚望远镜紧凑阵列获得的，覆盖面积为2.2 ° × 2°。四个速度分量被确定，在日心速度为-23，7，59和140公里秒-1。虽然7 km s-1的气体来自银河系，140 km s-1的气体很可能与麦哲伦流有关，但其他两个成分的情况尚不确定。然而，有人认为，-23 km s-1的分量可能与凤凰有关，因为：（1）它有一个紧凑的结构，与光学图像只有轻微的偏移，（2）它的H I质量为105 M Ω，这是在这样一个系统中可以预期的，（3）它有一个确定的速度梯度，（4）它位于凤凰座以西，这与已经怀疑的最后一个星星形成幕的自东向西传播相一致。由于在凤凰星的距离上意味着巨大的质量（105 × 106 M），也因为它的范围很大，+59 km s-1的分量很可能没有关联。仍然需要光学速度来确认这些可能的关联。
New results are presented for a mosaic mapping of the H I in the field of the Local Group dwarf galaxy Phoenix. The observations, obtained with the Australia Telescope Compact Array, cover an area of ∼2° × 2°. Four velocity components are identified, at heliocentric velocities of -23, 7, 59, and 140 km s-1. While the gas at 7 km s-1 is of Galactic origin and the gas at 140 km s-1 is most likely associated with the Magellanic Stream, the situation for the two other components is unsure. However, it is suggested that the component at -23 km s-1 is probably associated with Phoenix because: (1) it has a compact structure and is only slightly offset from the optical image, (2) its H I mass of ∼105 M⊙ is what can be expected in such a system, 3) it has a definite velocity gradient, (4) its location west of Phoenix is compatible with the already suspected self-propagation from east to west of the last star formation episode. Because of the large mass (∼5 × 106 M⊙) implied if at the distance of Phoenix and also because of its large extent, the component at +59 km s-1 is most likely not associated. Optical velocities are still needed to confirm or not those possible associations.