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arXiv 0809.0891astro-ph
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用Subaru望远镜研究相互作用的E+A(后星爆)系统的空间分辨中分辨光谱学

Spatially-Resolved Medium Resolution Spectroscopy of an Interacting E+A (post-starburst) System with the Subaru telescope

Tomotsugu Goto, Masafumi Yagi, Chisato Yamauchi

摘要:

我们对一个邻近的E+A(后星暴)星系系统SDSSJ 161330.18 +510335.5进行了空间分辨的中分辨率长缝光谱学研究。这个E+A星系在其前方14 kpc处有一个明显的伴星系,其速度差为61.8km/s。我们发现E+A星系的H $δ$等效宽度(EW)大于7千秒差距(8.5kpc)。E+A星系有一个弱的[OIII]辐射(EW $\sim$ 1 μ m),距Balmer吸收线峰值约$\sim$ 2.6 kpc。我们探测到伴星系的自转速度为$>$ 175 km/s。伴星的前身可能是一个有旋转支撑的被动S 0星系。E+A星系的年龄在熄灭恒星形成后估计为1亿至5亿年,其中心有稍微年轻的恒星星族。这些发现与一个简单的图片不一致,其中动力学相互作用产生了导致中央星暴/后星暴的气体储层的下沉。相反,我们的研究结果提出了一个重要的例子,即星系-星系相互作用可以触发整个星系的后星暴现象。

英文摘要:

We have performed a spatially-resolved medium resolution long-slit spectroscopy of a nearby E+A (post-starburst) galaxy system, SDSSJ161330.18+510335.5. This E+A galaxy has an obvious companion galaxy 14kpc in front with the velocity difference of 61.8 km/s. Both galaxies have obviously disturbed morphology We have found that H$δ$ equivalent width (EW) of the E+A galaxy is greater than 7Ågalaxy wide (8.5 kpc). The E+A galaxy have a weak [OIII] emission (EW$\sim$1Å) by $\sim$2.6 kpc offset from the peak of the Balmer absorption lines. We detected a rotational velocity in the companion galaxy of $>$175km/s. The progenitor of the companion may have been a rotationally-supported, but yet passive S0 galaxy. The age of the E+A galaxy after quenching the star formation is estimated to be 100-500 Myr, with its centre having slightly younger stellar population. These findings are inconsistent with a simple picture where the dynamical interaction creates infall of the gas reservoir that causes the central starburst/post-starburst. Instead, our results present an important example where the galaxy-galaxy interaction can trigger a galaxy-wide post-starburst phenomena.

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。

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