Arp 65 interaction debris: massive H I displacement and star formation
Arp 65 interaction debris: massive H I displacement and star formation
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Arp 65 相互作用碎片：大规模 H I 位移和恒星形成
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
B. Sohn
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文献类型：
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作者：
C. Sengupta;T. Scott;S. Paudel;D. Saikia;K. Dwarakanath;B. Sohn
上下文。已知星系对之间的合并前潮汐相互作用会引起恒星和星际介质成分的形态和运动学的重大变化。大量的气体和恒星经常被发现被扰动或移位为潮汐碎片。这些碎片随后演变，有时形成恒星，偶尔形成潮汐矮星系。在这里，我们展示了我们对Arp 65的H - i研究的结果，这是一个相互作用的对，承载着扩展的H - i潮汐碎片。目标。为了了解由相互作用的星系对产生的潮汐碎片的演化，包括原地恒星和潮汐矮星系的形成，我们正在相互作用的星系对样本中绘制H i。Arp 65对是这个样本中最新被映射的成员。方法。我们用巨型米波射电望远镜进行了分辨率为h21cm的线调查。我们利用我们的H测量数据以及可用的SDSS光学，斯皮策红外和GALEX紫外数据来研究潮汐碎片的演化以及H与其中恒星形成区域的相关性。结果。在Arp 65中，我们看到了一个高冲击力的合并前潮汐相互作用，涉及一对大质量星系（NGC90和NGC93），它们的恒星质量比为~ 1:3。这种相互作用可能发生在约1.0‐2.5 × 108年前，似乎将NGC90中很大一部分的H i（包括最高柱密度的H i）移出了它的光盘。我们还在NGC90的外盘发现了持续扩展的恒星形成过程。在主要的恒星形成区，我们发现H柱密度为~ 4.7 × 10 20 cm−2或更低。但在NGC90的柱密度最高的H i碎片SE中没有发现恒星形成的迹象。这表明在高密度的H - i碎片内的条件仍然不利于恒星的形成，它重申了高H - i柱密度可能是恒星形成的必要条件，但不是充分条件。
Context. Pre‐merger tidal interactions between pairs of galaxies are known to induce significant changes in the morphologies and kinematics of the stellar and interstellar medium components. Large amounts of gas and stars are often found to be disturbed or displaced as tidal debris. This debris then evolves, sometimes forming stars and occasionally forming tidal dwarf galaxies. Here we present results from our H i study of Arp 65, an interacting pair hosting extended H i tidal debris. Aims. In an effort to understand the evolution of tidal debris produced by interacting pairs of galaxies, including in situ star and tidal dwarf galaxy formation, we are mapping H i in a sample of interacting galaxy pairs. The Arp 65 pair is the latest member of this sample to be mapped. Methods. Our resolved H i 21 cm line survey is being carried out using the Giant Metrewave Radio Telescope. We used our H i survey data as well as available SDSS optical, Spitzer infra-red and GALEX UV data to study the evolution of the tidal debris and the correlation of H i with the star-forming regions within it. Results. In Arp 65 we see a high impact pre‐merger tidal interaction involving a pair of massive galaxies (NGC90 and NGC93) that have a stellar mass ratio of ∼1:3. The interaction, which probably occurred ∼1.0‐2.5 × 10 8 yr ago, appears to have displaced a large fraction of the H i in NGC90 (including the highest column density H i) beyond its optical disk. We also find extended on-going star formation in the outer disk of NGC90. In the major star-forming regions, we find the H i column densities to be ∼4.7 × 10 20 cm −2 or lower. But no signature of star formation was found in the highest column density H i debris SE of NGC90. This indicates conditions within the highest density H i debris remain hostile to star formation and it reaffirms that high H i column densities may be a necessary but not sufficient criterion for star formation.