本文给出了18个具有多峰Ly-alpha轮廓的z~2-3恒星形成星系的Ly-alpha发射线运动学的新结果。我们的大型光谱数据库的紫外线选择的恒星形成星系在这些红移,我们已经确定,约30%的这样的对象与可检测的Ly-alpha发射显示多峰的发射轮廓。这些配置文件提供了额外的限制逃逸的Ly-alpha光子,由于丰富的速度结构的出射线。尽管最近在模拟Ly-alpha从恒星形成星系中逃逸的高红移方面取得了进展,但模型和数据之间的比较往往缺少关键的观测信息。使用H-alpha(z~2)和[OIII] 5007(z~3)的Keck II NIRSPEC光谱,我们测量了样本中物体的准确系统红移、静止框架光学星云速度色散和发射线通量。精确的系统红移使我们能够将多峰Ly-alpha分布转化为速度空间,揭示了大多数(11/18)显示双峰发射跨越速度场零点,具有更强的红边发射。我们将我们的数据与高红移星系周围流出和下落气体分布的简单模型的预测进行比较。虽然流行的“壳”模型提供了一个定性的匹配与许多观测的Ly-alpha发射,我们发现,在细节上有重要的差异之间的模型和数据,以及问题的应用框架的膨胀薄壳的气体来解释高红移星系光谱。我们的数据突出了这些不一致性,以及在未来的高红移星系外流和流入模型中成功的关键因素。[摘要]
英文摘要:
We present new results on the Ly-alpha emission-line kinematics of 18 z~2-3 star-forming galaxies with multiple-peaked Ly-alpha profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have determined that ~30% of such objects with detectable Ly-alpha emission display multiple-peaked emission profiles. These profiles provide additional constraints on the escape of Ly-alpha photons due to the rich velocity structure in the emergent line. Despite recent advances in modeling the escape of Ly-alpha from star-forming galaxies at high redshifts, comparisons between models and data are often missing crucial observational information. Using Keck II NIRSPEC spectra of H-alpha (z~2) and [OIII] 5007 (z~3), we have measured accurate systemic redshifts, rest-frame optical nebular velocity dispersions and emission-line fluxes for the objects in the sample. Accurate systemic redshifts allow us to translate the multiple-peaked Ly-alpha profiles into velocity space, revealing that the majority (11/18) display double-peaked emission straddling the velocity-field zeropoint with stronger red-side emission. We compare our data with the predictions of simple models for outflowing and infalling gas distributions around high-redshift galaxies. While popular "shell" models provide a qualitative match with many of the observations of Ly-alpha emission, we find that in detail there are important discrepancies between the models and data, as well as problems with applying the framework of an expanding thin shell of gas to explain high-redshift galaxy spectra. Our data highlight these inconsistencies, as well as illuminating critical elements for success in future models of outflow and infall in high-redshift galaxies. [Abridged]
Type 2 Active Galactic Nuclei with Double-Peaked [OIII] Lines. II. Single AGNs with Complex Narrow-Line Region Kinematics are More Common than Binary AGNs
Kiloparsec-scale Spatial Offsets in Double-peaked Narrow-line Active Galactic Nuclei. I. Markers for Selection of Compelling Dual Active Galactic Nucleus Candidates
具有kpc尺度分离的双活动星系核(AGN)的合并残余星系应该是广泛存在的,这是星系合并和触发气体吸积到超大质量黑洞上的结果,但很少观察到双活动星系核。斯隆数字巡天中具有双峰窄活动星系核发射线的星系核是可能的双重活动星系核候选者,但它们的双峰轮廓也可能是气体运动学或活动星系核驱动的流出和喷流在小或大尺度上的结果。为了区分这两种情况,我们利用Lick、Palomar和MMT天文台对SDSS中81个双峰窄线活动星系核在0.03 < z < 0.36处进行了长缝光谱观测,获得了活动星系核辐射的空间分布。我们发现,所有81个系统都表现出双活动星系核的发射分量与~kpc的投影空间分离的天空,这表明他们是由kpc尺度的双重活动星系核或kpc尺度的外流,喷流,或旋转的气体盘。此外,我们发现,子样本(58%)的对象与空间紧凑的发射成分可能优先产生的双重活动星系核,而子样本(42%)的空间扩展的发射成分可能优先产生的活动星系核流出。我们还发现,对于32%的样本的两个活动星系核的发射组件优先与宿主星系主轴对齐,预期的双活动星系核在宿主星系的潜在轨道。我们的研究结果既缩小了产生双重活动星系核成分的可能物理机制的列表,并提出了从双峰窄线活动星系核的完整样本中选择最有希望的双重活动星系核候选者的几个观测标准。使用这些标准,我们确定了17个最引人注目的双重活动星系核候选者在我们的样本。
Double-Peaked Ly$α$ Emission during Reionization Requires Nearby Voids and a Favorable Local Ionizing Background
Institute for Basic Science(韩国基础科学研究院);Center for Computational Sciences(计算科学中心);The University of Texas at Dallas(德克萨斯大学达拉斯分校);Chungbuk National University(忠北国立大学);Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS UMR 7550(斯特拉斯堡天文台,斯特拉斯堡大学,法国国家科学研究中心);Institut d’Astrophysique de Paris, UMR 7095, CNRS, UPMC Univ. Paris VI(巴黎天体物理学研究所,法国国家科学研究中心,巴黎第六大学);The University of Nottingham(诺丁汉大学);University of Texas, Austin(德克萨斯大学奥斯汀分校);University of Sussex(萨塞克斯大学)