标题： 到 z=1.2 的不同形态类型的星系亮度函数 显示英文标题

标题： Galaxy luminosity function per morphological type up to z=1.2

摘要： 我们计算了从 z=1.2 以来星系中由核球和盘主导的 B 波段（静止框架）光度函数 (LF) 的演化。我们使用了来自 VIMOS-VLT 深度巡天的 605 条光谱红移样本（I_{AB}<24），以及来自 COMBO-17 多色数据的 3555 个具有 photometric redshifts 的星系，并结合了来自 Great Observatories Origin Deep Survey 的多色 HST/ACS 图像。我们根据在静止框架 B 波段测量的不对称性和集中性参数，将样本分为核球和盘主导的群体。我们发现，在 z=0.4-0.8 时，与核球主导群体 (\alpha=-0.53 \pm 0.13) 相比，盘主导群体的 LF 斜率显著更陡峭 (\alpha=-1.19 \pm 0.07)。 棒旋星系的LF由两个在静止框架颜色上分开的明显不同的星系族群组成：68%为红色（B-I）\_{AB}>0.9且亮星系，其LF斜率强烈下降（\alpha =+0.55 \pm 0.21），以及32%为蓝色（B-I）\_{AB}<0.9且更紧凑的星系，它们占据了LF的暗端。 我们观察到，在z~1时，红棒旋星系已经很好地就位，但这个族群的体密度在z~1和z~0.6之间增加了2.7倍。 这可能与等级成团模型中大椭圆星系的形成有关。 此外，我们还观察到，在z~1和z~0.6之间，蓝棒旋星系变暗了0.7个星等。 这个较暗且更紧凑的星系族群中的星系可能是本地矮椭圆星系的前身。 显示英文摘要

摘要： We have computed the evolution of the rest-frame B-band luminosity function (LF) for bulge and disk-dominated galaxies since z=1.2. We use a sample of 605 spectroscopic redshifts with I_{AB}<24 in the Chandra Deep Field South from the VIMOS-VLT Deep Survey, 3555 galaxies with photometric redshifts from the COMBO-17 multi-color data, coupled with multi-color HST/ACS images from the Great Observatories Origin Deep Survey. We split the sample in bulge- and disk-dominated populations on the basis of asymmetry and concentration parameters measured in the rest-frame B-band. We find that at z=0.4-0.8, the LF slope is significantly steeper for the disk-dominated population (\alpha=-1.19 \pm 0.07) compared to the bulge-dominated population (\alpha=-0.53 \pm 0.13). The LF of the bulge-dominated population is composed of two distinct populations separated in rest-frame color: 68% of red (B-I)_{AB}>0.9 and bright galaxies showing a strongly decreasing LF slope \alpha=+0.55 \pm 0.21, and 32% of blue (B-I)_{AB}<0.9 and more compact galaxies which populate the LF faint-end. We observe that red bulge-dominated galaxies are already well in place at z~1, but the volume density of this population is increasing by a factor 2.7 between z~1 and z~0.6. It may be related to the building-up of massive elliptical galaxies in the hierarchical scenario. In addition, we observe that the blue bulge-dominated population is dimming by 0.7 magnitude between z~1 and z~0.6. Galaxies in this faint and more compact population could possibly be the progenitors of the local dwarf spheroidal galaxies.