2018年4月1日
ALMA Multiple-transition Observations of High-density Molecular Tracers in Ultraluminous Infrared Galaxies
Astrophysical Journal
- ,
- ,
- 巻
- 856
- 号
- 2
- 記述言語
- 英語
- 掲載種別
- 機関テクニカルレポート,技術報告書,プレプリント等
- DOI
- 10.3847/1538-4357/aab42f
- 出版者・発行元
- Institute of Physics Publishing
We present the results of our ALMA observations of 11 (ultra)luminous infrared galaxies ((U)LIRGs) at J = 4-3 of HCN, HCO+, and HNC and J = 3-2 of HNC. This is an extension of our previously published HCN and HCO+ J = 3-2 observations to multiple rotational J-transitions of multiple molecules, to investigate how molecular emission line flux ratios vary at different J-transitions. We confirm that ultraluminous infrared galaxies (ULIRGs) that contain or may contain luminous obscured active galactic nuclei (AGNs) tend to show higher HCN-to-HCO+ flux ratios than starburst galaxies, both at J = 4-3 and J = 3-2. For selected HCN-flux-enhanced AGN-important ULIRGs, our isotopologue H13CN, H13CO+, and HN13C J = 3-2 line observations suggest a higher abundance of HCN than HCO+ and HNC, which is interpreted to be primarily responsible for the elevated HCN flux in AGN-important galaxies. For such sources, the intrinsic HCN-to-HCO+ flux ratios after line opacity correction will be higher than the observed ratios, making the separation between AGNs and starbursts even larger. The signature of the vibrationally excited (v 2 = 1f) HCN J = 4-3 emission line is seen in one ULIRG, IRAS 12112-0305 NE. P Cygni profiles are detected in the HCO+ J = 4-3 and J = 3-2 lines toward IRAS 15250+3609, with an estimated molecular outflow rate of ∼250-750 M o yr-1. The SiO J = 6-5 line also exhibits a P Cygni profile in IRAS 12112+0305 NE, suggesting the presence of shocked outflow activity. Shock tracers are detected in many sources, suggesting ubiquitous shock activity in the nearby ULIRG population.
- リンク情報
- ID情報
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- DOI : 10.3847/1538-4357/aab42f
- ISSN : 1538-4357
- ISSN : 0004-637X
- arXiv ID : arXiv:1803.02408
- SCOPUS ID : 85045550073