ALMA Sub-arcsecond-resolution 183 GHz H2O and Dense Molecular Line Observations of Nearby Ultraluminous Infrared Galaxies
ALMA Sub-arcsecond-resolution 183 GHz H2O and Dense Molecular Line Observations of Nearby Ultraluminous Infrared Galaxies
复制标题
DOI：
10.3847/1538-4357/ac3a68
复制
发表时间：
2021-11
期刊：
影响因子：
--
通讯作者：
M. Imanishi;K. Nakanishi;T. Izumi;S. Baba
中科院分区：
文献类型：
--
作者：
M. Imanishi;K. Nakanishi;T. Izumi;S. Baba
我们提出了10个（超）发光红外星系（[U] ligg；红外光度≥1011.7 L⊙）在z 104 cm−3分子（HCN， HCO+和HNC J = 2 - 1）和183 GHz H2O 31,3 - 22,0发射线的ALMA ~ 2 mm，≤1″-分辨率观测结果。活动星系核(AGN)-重要的ulrgs往往表现出比星爆分类源更高的HCN/HCO+ J = 2-1通量比。我们在几乎所有agn重要的ulrgs中检测到183 GHz的H2O发射，并且在HCN J = 2-1的两个源中发现H2O发射升高，相对于HCO+ J = 2-1。除了一个ulrg（超级天线）外，水的发射大部分来自整个核区（约1 kpc），而不是位于核中心的源自agn的巨型激光器（≪1 kpc）。由HCO+ J = 2-1光度产生的核（~ 1 kpc）致密分子气体质量为约几× 108 M⊙，其耗尽时间在所有源中估计为约106年。在少数(U) ligs中检测到HCN和HNC的振动激发的J = 2-1发射谱线，而HCO+的则没有。结果表明，在中红外辐射暴露的能量源周围的最内层区域，HCO+和HNC的丰度明显低于HCN。在我们的10 (U) ligg的ALMA ~ 2 mm数据中，在~ 10″内偶然发现了两个连续体源，它们可能是z > 1的红外发光尘埃星系和blazar。
We present the results of ALMA ∼2 mm, ≲1″-resolution observations of 10 (ultra)luminous infrared galaxies ([U]LIRGs; infrared luminosity ≳1011.7 L ⊙) at z 104 cm−3) molecular (HCN, HCO+, and HNC J = 2–1) and 183 GHz H2O 31,3–22,0 emission lines. Active galactic nucleus (AGN)-important ULIRGs tend to show higher HCN/HCO+ J = 2–1 flux ratios than starburst-classified sources. We detect 183 GHz H2O emission in almost all AGN-important ULIRGs, and elevated H2O emission is found in two sources with elevated HCN J = 2–1 emission, relative to HCO+ J = 2–1. Except one ULIRG (the Superantennae), the H2O emission largely comes from the entire nuclear regions (∼1 kpc), rather than an AGN-origin megamaser at the very center (≪1 kpc). Nuclear (∼1 kpc) dense molecular gas mass derived from HCO+ J = 2–1 luminosity is ≳ a few × 108 M ⊙, and its depletion time is estimated to be ≳106 yr in all sources. Vibrationally excited J = 2–1 emission lines of HCN and HNC are detected in a few (U)LIRGs, but those of HCO+ are not. It is suggested that in mid-infrared-radiation-exposed innermost regions around energy sources, HCO+ and HNC are substantially less abundant than HCN. In our ALMA ∼2 mm data of 10 (U)LIRGs, two continuum sources are serendipitously detected within ∼10″, which are likely to be an infrared-luminous dusty galaxy at z > 1 and a blazar.