A Merger Origin for X Structures in S0 Galaxies
A Merger Origin for X Structures in S0 Galaxies
复制标题
S0 星系中 X 结构的合并起源
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
Mike Bolte
中科院分区：
文献类型：
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作者：
C. Mihos;I. Walker;L. Hernquist;Claudia Mendes de Oliviera;Mike Bolte
利用数值模拟，我们研究了盘状星系对低质量伴星系合并的响应。当盘星系的伴星吸积时，盘星系会在伴星的扰动下形成一个强棒。在吸积事件结束后，由于弯曲不稳定性，棒垂直弯曲，将盘物质送出盘平面。当从侧面观察时，这些物质形成了X形特征，在形态上类似于在几个S 0/Sa星系中观察到的X结构。这里描述的机制将之前提出的吸积和棒不稳定性假设结合起来，将X结构形成为合并诱导的S 0星系形成和演化的自洽情景。为了补充这些模型，我们还提出了奇特的S 0星系希克森87 a的观测。合并模型中描述的厚盘、等照度线翘曲和强X结构在希克森87 a中都很明显，这表明这个星系可能是这种合并引起的星系演化的一个很好的例子。
Using numerical simulation, we study the response of a disk galaxy to a merger involving a low-mass satellite companion. During a prograde satellite accretion, the disk galaxy forms a strong bar in response to the perturbation of the companion. After the accretion event is over, the bar buckles vertically due to a bending instability, sending disk material well out of the disk plane. The material forms into an X-shaped feature when seen edge-on, morphologically similar to X structures observed in several S0/Sa galaxies. The mechanism described here unites previously suggested accretion and bar instability hypotheses for forming X structures into a self-consistent scenario for merger-induced formation and evolution of S0 galaxies. To complement these models, we also present observations of the peculiar S0 galaxy Hickson 87a. The thick disk, isophotal warping, and strong X structure described in the merger model are all evident in Hickson 87a, suggesting this galaxy may be an excellent example of such merger-induced galaxy evolution.