论文标题
SDSS-IV漫画：何时在星系上印刷形态？
SDSS-IV MaNGA: When is morphology imprinted on galaxies?
论文作者
论文摘要
关于我们在当今的银河系中看到的形态很久以前，这仍然是一个悬而未决的问题。对不同红移的星系群体的研究表明，形态的平衡随着时间的流逝而发生了变化，但是这种快照无法揭示各个星系经历形态转化的典型时间尺度，也无法发现当今不同类型星系的祖细胞。但是，这些研究还表明，在红移中，形态学与恒星形成率之间存在牢固的联系，这提供了形态转化的替代探测。因此，通过出色的“化石记录”方法，我们在SDSS-IV漫画调查中得出了4342个星系样品样本的恒星形成率和恒星质量的演变，并表明人群的平均演变与先前研究的已知行为表现出良好的一致性。尽管银河系的同期形态与恒星形成率之间的相关性在大量的回避时间之间是很强的，但我们发现银河系的当前形态仅与其相对较新的（〜2 Gyr）恒星形成史相关。因此，我们发现有力的证据表明，形态学向星系的当前外观发生在时间尺度上短短数十亿年。
It remains an open question as to how long ago the morphology that we see in a present-day galaxy was typically imprinted. Studies of galaxy populations at different redshifts reveal that the balance of morphologies has changed over time, but such snapshots cannot uncover the typical timescales over which individual galaxies undergo morphological transformation, nor which are the progenitors of today's galaxies of different types. However, these studies also show a strong link between morphology and star-formation rate over a large range in redshift, which offers an alternative probe of morphological transformation. We therefore derive the evolution in star-formation rate and stellar mass of a sample of 4342 galaxies in the SDSS-IV MaNGA survey through a stellar population "fossil record" approach, and show that the average evolution of the population shows good agreement with known behaviour from previous studies. Although the correlation between a galaxy's contemporaneous morphology and star-formation rate is strong over a large range of lookback times, we find that a galaxy's present-day morphology only correlates with its relatively recent (~2 Gyr) star-formation history. We therefore find strong evidence that morphological transitions to galaxies' current appearance occurred on timescales as short as a few billion years.
