标题： 中间红移的恒星形成星系：形态、年龄和大小 显示英文标题

标题： Star--forming galaxies at intermediate redshifts: morphology, ages and sizes

摘要： 我们展示了使用哈勃太空望远镜（HST）的WFPC2（F300W）获得的最深紫外图像的分析结果，这是作为超深场观测计划的平行观测的一部分。 在0.2平方角秒面积上测量到的U波段10σ极限星等为m(AB)=27.5，比北半球深空场（HDF-North）深0.5个星等。 我们将U波段目录与在CDF-South的GOODS观测期间拍摄的ACS图像目录进行了匹配，并为306个匹配对象获得了测光红移。 我们发现，在0.2<z_phot<1.2范围内，UV选择的星系涵盖了所有主要的形态类型。 然而，在较低红移下，盘状星系更为常见， 即在0.2<z_phot<0.8范围内。 高红移天体（0.7<z_phot<1.2）平均而言比低红移天体更蓝，并具有典型的星爆光谱类型。 它们的形态表现为紧凑型、特殊型或低表面亮度星系。 在0.66<z_phot<1.5范围内，UV选择的星系平均半光度半径（在1200–1800 Å的静止框架下）为0.26 ± 0.01角秒（2.07 ± 0.08千秒差距）。 UV选择的星系平均比Lyman断层星系（LBGs）暗淡（M_B=-18.43±0.13），而我们的样本包括早期类型的星系，这些星系可能是大质量的，并且仅在其核心形成恒星，以及类似于LBGs但亮度低得多的星爆型系统。 这意味着即使是我们样本中的星爆也可能是LBGs的质量小得多，或者以更低的速率形成恒星，或者两者兼有。 低表面亮度星系与LBGs没有重叠，并形成了一个有趣的全新类别。 显示英文摘要

摘要： We present the analysis of the deepest near-UV image obtained with HST using the WFPC2(F300W) as part of the parallel observations of the Ultra Deep Field campaign. The U-band 10sigma limiting magnitude measured over 0.2 arcsec square is m(AB)=27.5 which is 0.5 magnitudes deeper than that in the HDF-North. We matched the U-band catalog with those in the ACS images taken during the GOODS observations of the CDF-South and obtained photometric-z for 306 matched objects. We find that the UV-selected galaxies span all the major morphological types at 0.2<z_phot<1.2. However, disks are more common at lower redshifts, 0.2<z_phot<0.8. Higher-z objects (0.7<z_phot<1.2) are on average bluer than lower-z and have spectral type typical of starbursts. Their morphologies are compact, peculiar or low surface brightness galaxies. The average half-light radius (rest-frame 1200--1800 A) of the UV-selected galaxies at 0.66<z_ phot<1.5 is 0.26 +- 0.01 arcsec (2.07 +- 0.08 kpc). The UV-selected galaxies are on average fainter (M_B=-18.43+-0.13) than Lyman Break Galaxies (M_B=-23+-1). Our sample includes early-type galaxies that are presumably massive and forming stars only in their cores, as well as starburst-type systems that are more similar to the LBGs, although much less luminous. This implies that even the starbursts in our sample are either much less massive than LBGs or are forming stars at a much lower rate or both. The low surface brightness galaxies have no overlap with the LBGs and form an interesting new class of their own.