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HCN observations of dense star-forming gas in high-redshift galaxies
文献类型：期刊论文
| 作者 | Gao, Yu ; Carilli, Chris L.; Solomon, Philip M.; Bout, Paul A. Vanden
|
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2007-05-10 |
| 卷号 | 660期号:2页码:L93-L96 |
| 关键词 | galaxies : formation galaxies : high-redshift galaxies : ISM galaxies : starburst infrared : galaxies ISM : molecules |
| ISSN号 | 0004-637X |
| 英文摘要 | We present here the sensitive HCN ( 1 - 0) observations made with the VLA of two submillimeter galaxies and two QSOs at high redshift. HCN emission is the signature of dense molecular gas found in giant molecular cloud (GMC) cores, the actual sites of massive star formation. We have made the first detection of HCN in a submillimeter galaxy, SMM J16359 + 6612. The HCN emission is seen with a signal-to-noise ratio of 4 sigma and appears to be resolved as a double source of less than or similar to 2 '' separation. Our new HCN observations, combined with previous HCN detections and upper limits, show that the FIR/ HCN ratios in these high-redshift sources lie systematically above the FIR/ HCN correlation established for nearby galaxies by about a factor of 2. Even considering the scatter in the data and the presence of upper limits, this is an indication that the FIR/ HCN ratios for the early universe molecular emissionline galaxies (EMGs) deviate from the correlation that fits Galactic GMC cores, normal spirals, and luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs, respectively). This indicates that the star formation rate per solar mass of dense molecular gas is higher in the high-z objects than in local galaxies including normal spirals, LIRGs, and ULIRGs. The limited HCN detections at high redshift show that the HCN/CO ratios for the high-z objects are high and are comparable to those of the local ULIRGs rather than those of normal spirals. This indicates that EMGs have a high fraction of dense molecular gas compared to total molecular gas traced by CO emission. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 学科主题 | Astronomy & Astrophysics |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | QUASAR HOST GALAXIES ; MOLECULAR GAS ; ULTRALUMINOUS GALAXIES ; INFRARED GALAXIES ; APM 08279+5255 ; EMISSION ; SEARCH ; STARBURSTS |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000246574400004 |
| 公开日期 | 2012-02-05 |
| 源URL | [http://159.226.72.40/handle/332002/2426]  |
| 专题 | 紫金山天文台_天体化学和行星科学实验室 |
| 作者单位 | 1.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China 2.CAS, Natl Astron Observ, Beijing, Peoples R China 3.Tianjin Normal Univ, Joint Inst Galaxies, Tianjin, Peoples R China 4.Tianjin Normal Univ, AGN, Tianjin, Peoples R China 5.Natl Radio Astron Observ, Socorro, NM 87801 USA 6.SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA 7.Natl Radio Astron Observ, Charlottesville, VA 22903 USA |
| 推荐引用方式 GB/T 7714 | Gao, Yu,Carilli, Chris L.,Solomon, Philip M.,et al. HCN observations of dense star-forming gas in high-redshift galaxies[J]. ASTROPHYSICAL JOURNAL,2007,660(2):L93-L96. |
| APA | Gao, Yu,Carilli, Chris L.,Solomon, Philip M.,&Bout, Paul A. Vanden.(2007).HCN observations of dense star-forming gas in high-redshift galaxies.ASTROPHYSICAL JOURNAL,660(2),L93-L96. |
| MLA | Gao, Yu,et al."HCN observations of dense star-forming gas in high-redshift galaxies".ASTROPHYSICAL JOURNAL 660.2(2007):L93-L96. |
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来源：紫金山天文台
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