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arXiv 1609.01737astro-ph.GA
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SDSS IV MaNGA -从恒星形成到静止的空间分辨过渡

SDSS IV MaNGA - The spatially resolved transition from star formation to quiescence

Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstei… 展开作者

Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstein, Kevin Bundy, Aleksandar M. Diamond-Stanic, Niv Drory, Timothy M. Heckman, David R. Law, Olena Malanushenko, Audrey Oravetz, Kaike Pan, Alexandre Roman-Lopes, Daniel Thomas, Anne-Marie Weijmans, Kyle B. Westfall, Renbin Yan

摘要:

使用空间分辨光谱从SDSS-IV的MANGA,我们已经证明,低电离发射线区域(LIERS)在本地星系的热演化恒星,而不是活跃的星系核的光电离的结果。LIER普遍存在于静止星系和星系中心区域,那里的恒星形成发生在更大的半径。我们把这两类星系分别称为扩展LIER(eLIER)和中央LIER(cLIER)星系。cLIERS是位于绿谷周围的晚型星系,位于恒星形成主序列和静止星系之间的过渡区。这些星系在恒星和气体中都显示出规则的圆盘旋转,尽管其中心恒星速度色散比相同质量的恒星形成星系更高。cLIERS是一致的缓慢淬火内向外的转变是与大规模的凸起,通过长期的演变指向凸起增长的重要性。eLIERS是形态上的早期类型,在它们的恒星星族、形态和中心恒星速度色散方面与没有线发射的被动星系没有区别。eLIERs中的电离气体表现出扰动和盘状运动学。当在气体中观察到大规模的流动/旋转时,它通常与恒星成分不一致。这些特征表明,eLIERS是被动星系窝藏残余的冷气体成分,获得主要通过外部吸积。重要的是,没有线发射的静止星系居住在更密集的环境中,并且具有比eLIERs显着更高的卫星部分。因此,环境效应可能是红色序列上无线星系存在的原因。

英文摘要:

Using spatially resolved spectroscopy from SDSS-IV MaNGA we have demonstrated that low ionisation emission line regions (LIERs) in local galaxies result from photoionisation by hot evolved stars, not active galactic nuclei. LIERs are ubiquitous in both quiescent galaxies and in the central regions of galaxies where star formation takes place at larger radii. We refer to these two classes of galaxies as extended LIER (eLIER) and central LIER (cLIER) galaxies respectively. cLIERs are late type galaxies located around the green valley, in the transition region between the star formation main sequence and quiescent galaxies. These galaxies display regular disc rotation in both stars and gas, although featuring a higher central stellar velocity dispersion than star forming galaxies of the same mass. cLIERs are consistent with being slowly quenched inside-out; the transformation is associated with massive bulges, pointing towards the importance of bulge growth via secular evolution. eLIERs are morphologically early types and are indistinguishable from passive galaxies devoid of line emission in terms of their stellar populations, morphology and central stellar velocity dispersion. Ionised gas in eLIERs shows both disturbed and disc-like kinematics. When a large-scale flow/rotation is observed in the gas, it is often misaligned relative to the stellar component. These features indicate that eLIERs are passive galaxies harbouring a residual cold gas component, acquired mostly via external accretion. Importantly, quiescent galaxies devoid of line emission reside in denser environments and have significantly higher satellite fraction than eLIERs. Environmental effects thus represent the likely cause for the existence of line-less galaxies on the red sequence.

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