论文标题
首次检测高红移时448 GHz Ortho-H2O线：探测Z = 3.63的Starburst核的结构
First detection of the 448 GHz ortho-H2O line at high redshift: probing the structure of a starburst nucleus at z = 3.63
论文作者
论文摘要
H2O的亚毫升旋转线是ISM温暖气体区域的强大探针，追踪尺度和结构，从KPC磁盘到银河核的最紧凑，最灰尘的区域。 448 GHz处的Ortho-H2O（423-330）线最近在当地的发光红外星系中检测到该线（Pereira-Santaella etal。2017），对激发条件提供了独特的限制，并且对高远的Galaxy Nuclei的ISM属性具有较高的远距离深度深度深度，以使其具有高度埋藏量。在这封信中，我们在Z = 3.63时使用ALMA的第一个高红移检测使用ALMA对448 GHz H2O（423-330）线进行了使用Alma的第一个高速检测。校正放大倍数后，448 GHz H2O线的光度为〜10^6 l_sun。结合另外三个先前检测到的H2O线，我们构建了一个“解决” SMG的尘土ISM结构的模型，并发现它由〜1 kpc的光学薄（光学深度（光学深度）（100μmτ_{100μmτ_{100} 〜0.3）磁盘组成，带有粉尘温度t_ {dust feast t_ emitions tode tove a emit d l_ emit 1 l_e emit 1 l_ emit 1 l_ emit 1 l_ emit 1 l_ emit1222 σ_{ir} = 4e11 l_sun kpc^{ - 2}，以及一个非常紧凑的（0.1 kpc）的灰尘 - 灰尘（τ_{100} \ gtrsim 1）核心，具有非常温暖的灰尘（100 k）和σ_{ir} = 8e12 l_sun kpc^}。核心组件中的H2O丰度X_ {H2O}〜（0.3-5）E {-5}，至少比磁盘组件中的一个数量级。光学厚的芯具有爱丁顿限制的Starburst的特性，提供了证据表明，尘埃上的辐射压力能够在高红移处支撑ISM。我们的模型揭示的多组分ISM结构表明，灰尘和分子（例如H2O）存在于以高度不同的条件和尺度为特征的区域中，从核从细胞核延伸到SMG的更广泛的区域。
Submillimeter rotational lines of H2O are a powerful probe in warm gas regions of the ISM, tracing scales and structures ranging from kpc disks to the most compact and dust-obscured regions of galactic nuclei. The ortho-H2O(423-330) line at 448 GHz, which was recently detected in a local luminous infrared galaxy (Pereira-Santaella et al. 2017), offers a unique constraint on the excitation conditions and ISM properties in deeply buried galaxy nuclei since the line requires high far-IR optical depths to be excited. In this letter, we report the first high-redshift detection of the 448 GHz H2O(423-330) line using ALMA, in a strongly lensed submillimeter galaxy (SMG) at z=3.63. After correcting for magnification, the luminosity of the 448 GHz H2O line is ~10^6 L_sun. In combination with three other previously detected H2O lines, we build a model that "resolves" the dusty ISM structure of the SMG, and find that it is composed of a ~1 kpc optically thin (optical depth at 100μm τ_{100}~0.3) disk component with dust temperature T_{dust} \approx 50 K emitting a total infrared power of 5e12 L_sun with surface density Σ_{IR}=4e11 L_sun kpc^{-2}, and a very compact (0.1 kpc) heavily dust-obscured (τ_{100} \gtrsim 1) nuclear core with very warm dust (100 K) and Σ_{IR}=8e12 L_sun kpc^{-2}. The H2O abundance in the core component, X_{H2O}~(0.3-5)e{-5}, is at least one order of magnitude higher than in the disk component. The optically thick core has the characteristic properties of an Eddington-limited starburst, providing evidence that radiation pressure on dust is capable of supporting the ISM in buried nuclei at high redshifts. The multi-component ISM structure revealed by our models illustrates that dust and molecules such as H2O are present in regions characterized by highly differing conditions and scales, extending from the nucleus to more extended regions of SMGs.
