论文标题
沿形态序列的星系老化，标志着凸起的生长和磁盘淬火
Aging of galaxies along the morphological sequence, marked by bulge growth and disk quenching
论文作者
论文摘要
我们使用附近星系的广泛的Efigi形态学分类来重新审视星系的颜色双峰性。 G，R和I频段中的Galaxy SDSS图像使用source Xtractor ++分解为Bulge+Disk。与Galex NUV相辅相成的GRI光度法制成的光谱能量分布与ZPEG拟合，以估计整个星系的恒星质量和特定的星形速率（SSFR）以及它们的凸起和磁盘成分。绝对NUV-R颜色与恒星质量图显示了星系的当前SSFR与其恒星质量之间的连续关系，这些关系涵盖了哈勃序列的所有形态类型。不规则的星系构成蓝云，绿色平原（以前为谷谷）由早期型螺旋（S0A-SA）组成，而红色序列则包含所有张力和椭圆形星系，具有系统的较高质量，用于椭圆形。绿色平原上的星系在其凸起与总体质量比和从伪凸起到经典凸起的系统变化以及系统的变化以及将其解释为磁盘中的恒星形成褪色的明显变红。因此，绿色平原是一个过渡区域，由于快速淬火，我们排除了主要快速的过境。我们建议，恒星形成增加的示踪剂（明亮的HII区域，螺旋臂，絮凝）决定了恒星形成星系的主要序列有限的散射。绿色平原的膝盖的所有螺旋和螺旋臂的高频以及更强的螺旋臂和絮状，这表明内部动力学（可能是由飞鸟或合并触发的）可能是大型磁盘星系增长的关键，这是巨大的磁盘生长，这是恒星形成到静止的星系的标记。然后可以将哈勃序列视为星系物理进化的反向序列。
We revisit the color bimodality of galaxies using the extensive EFIGI morphological classification of nearby galaxies. The galaxy SDSS images in the g, r and i bands are decomposed as bulge+disk using SourceXtractor++. The spectral energy distributions made of our gri photometry complemented with GALEX NUV are fitted with ZPEG in order to estimate the stellar masses and specific star formations rates (sSFR) of whole galaxies as well as their bulge and disk components. The absolute NUV-r color versus stellar mass diagram shows a continuous relationship between the present sSFR of galaxies and their stellar mass, that spans all morphological types of the Hubble sequence. Irregular galaxies to Sab spirals make up the Blue Cloud, the Green Plain (formerly Valley) is made up of early-type spirals (S0a-Sa) while the Red Sequence contains all lenticular and elliptical galaxies, with systematically higher masses for the ellipticals. Galaxies across the Green Plain undergo a marked growth by a factor 2 to 3 in their bulge-to-total mass ratio and a systematic profile change from pseudo to classical bulges, as well as a significant reddening interpreted as star formation fading in their disks. Therefore, the Green Plain is a transition region, and we exclude a predominantly quick transit due to rapid quenching. We suggest that tracers of increased star formation (bright HII regions, spiral arms, flocculence) determine the limited scatter of the Main Sequence of star-forming galaxies. The high frequency of bars for all spirals as well as the stronger spiral arms and flocculence in the knee of the Green Plain suggest that internal dynamics, likely triggered by flybys or mergers, may be the key to the bulge growth of massive disk galaxies, marker of the aging of galaxies from star forming to quiescence. The Hubble sequence can then be considered as an inverse sequence of galaxy physical evolution.
