标题： 红移z<1时次半阻尼莱曼阿尔法系统的SOAR成像观测 显示英文标题

标题： SOAR Imaging of sub-Damped Lyman-Alpha Systems at z<1

摘要： 我们利用SOAR望远镜和SOI相机，展示了五个包含红移z<1的次饱和Lyman-alpha系统的类星体环境的深度地面成像。 我们在这些小视场中检测到明显的星系过剩现象，这支持了我们正在探测导致吸收系统的星系的假设。 假定这些星系处于吸收线系统的红移上，我们发现在QSO周围10角秒范围内的四个场中有亮星系（L>L*）。 与之前针对这些红移上的DLA系统的成像调查不同，后者表明系统宿主星系具有多种形态类型和亮度，我们在这些次DLA场中检测到的星系似乎都是亮星系（L>L*）。 对于z=0.8866处Q1009-0026方向上的吸收体，我们有光谱确认候选星系位于吸收体的红移上，在影响参数约为 ~35 kpc 的情况下，亮度为 3 < L/L* < 8，具体取决于 K 校正的大小。 这些观测结果与次DLA可能比DLA系统更能代表大质量星系的观点一致。 吸收体的环境从星系的内部盘、明亮星系的外围到相互作用星系的边缘不等。 一些候选星系的大影响参数表明，星系外流或潮汐尾可能负责吸收中看到的物质。 我们在2sigma水平上发现HI柱密度与影响参数之间存在弱相关性，这可能是由于吸收线系统宿主星系的异质种群和随机取向角度所致。 此外，我们还检测到BL-Lac天体Q0826-2230的可能引力透镜图像。 显示英文摘要

摘要： We present deep ground based imaging of the environments of five QSOs that contain sub-Damped Lyman-alpha systems at z<1 with the SOAR telescope and SOI camera. We detect a clear surplus of galaxies in these small fields, supporting the assumption that we are detecting the galaxies responsible for the absorption systems. Assuming these galaxies are at the redshift of the absorption line systems, we detect luminous L>L* galaxies for four of the five fields within 10" of the QSO. In contrast to previous imaging surveys of DLA systems at these redshifts, which indicate a range of morphological types and luminosities for the host galaxies of the systems, the galaxies we detect in these sub-DLA fields appear to be luminous (L>L*). In the case of the absorber towards Q1009-0026 at z=0.8866 we have spectroscopic confirmation that the candidate galaxy is at the redshift of the absorber, at an impact parameter of ~35 kpc with a luminosity of 3 < L/L* < 8 depending on the magnitude of the K-correction. These observations are in concordance with the view that sub-DLAs may be more representative of massive galaxies than DLA systems. The environments of the absorbers span a range of types, from the inner disk of a galaxy, the periphery of a luminous galaxy, and the outskirts of interacting galaxies. The large impact parameters to some of the candidate galaxies suggest that galactic outflows or tidal tails are likely responsible for the material seen in absorption. We find a weak correlation between N(HI) and the impact parameter at the 2 sigma level, which may be expected from the heterogeneous population of galaxies hosting the absorption line systems and random orientation angles. In addition, we detect a possible gravitationally lensed image of the BL-Lac object Q0826-2230.