arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1507.04889astro-ph.GA
收藏

M81群相互作用星系的超极凸轮观

A Hyper Suprime-Cam View of the Interacting Galaxies of the M81 Group

Sakurako Okamoto, Nobuo Arimoto, Annette M. N. Ferguson, Edouard J. Bernard, Mike J. Irwin, Yoshihiko Yamada, Yousuke Utsumi

摘要:

我们提出的第一个结果的M81组进行了广泛的领域映射调查与超Suprime-Cam的斯巴鲁望远镜。我们的深测光达到$\sim2$星等低于红巨星分支(RGB)的尖端,并揭示了在M81的距离$\sim 100\times115$千秒差距的区域内,年老和年轻恒星的空间分布。年轻的恒星($\sim30-160$ Myr old)紧密地遵循中性氢的分布,可以在M81和NGC 3077之间的恒星流中找到,也可以在许多外围的恒星协会中找到,包括已知的Arp's Loop,Holmberg 3077,IX,M82晕中的弧,BK 3 N和Garland。这些分组中的许多在RGB地图中没有对应物,这表明它们可能是真正年轻的系统。我们的巡天观测还首次揭示了M81、M82和NGC 3077周围RGB恒星的非常扩展的($\geq 2\times \rm{R_{25}}$)晕,以及连接这些系统的微弱潮汐流。M82和NGC 1,3077的晕呈现出高度扰动的形态,推测是最近引力相遇和它们持续破坏的结果。虽然M81、NGC 1、3077的晕和M82的内晕具有相似的$(g-i)_{0}$颜色,但M82的外晕明显更蓝,表明它更贫金属。值得注意的是,我们对M81星系群的深度全景图表明,长期以来已知的HI中存在的复杂性在低表面亮度恒星成分中同样匹配。

英文摘要:

We present the first results of a wide-field mapping survey of the M81 group conducted with Hyper Suprime-Cam on the Subaru Telescope. Our deep photometry reaches $\sim2$ magnitudes below the tip of the red giant branch (RGB) and reveals the spatial distribution of both old and young stars over an area of $\sim 100\times115$ kpc at the distance of M81. The young stars ($\sim30-160$ Myr old) closely follow the neutral hydrogen distribution and can be found in a stellar stream between M81 and NGC\,3077 and in numerous outlying stellar associations, including the known concentrations of Arp's Loop, Holmberg\,IX, an arc in the halo of M82, BK3N, and the Garland. Many of these groupings do not have counterparts in the RGB maps, suggesting they may be genuinely young systems. Our survey also reveals for the first time the very extended ($\geq 2\times \rm{R_{25}}$) halos of RGB stars around M81, M82 and NGC\,3077, as well as faint tidal streams that link these systems. The halos of M82 and NGC\,3077 exhibit highly disturbed morphologies, presumably a consequence of the recent gravitational encounter and their ongoing disruption. While the halos of M81, NGC\,3077 and the inner halo of M82 have the similar $(g-i)_{0}$ colors, the outer halo of M82 is significantly bluer indicating it is more metal-poor. Remarkably, our deep panoramic view of the M81 group demonstrates that the complexity long-known to be present in HI is equally matched in the low surface brightness stellar component.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑