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| Protonated hydrogen cyanide as a tracer of pristine molecular gas | |
Gong, Y.1; Du, F. J.2,3; Henkel, C.1,4,5 ; Jacob, A. M.1,6; Belloche, A.1; Wang, J. Z.7; Menten, K. M.1; Yang, W.1; Quan, D. H.5,8; Bop, C. T.9; Ortiz-Leon, G. N.10; Tang, X. D.5,11,12; Rugel, M. R.1,13,14; Liu, S.15
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| 2023-11-01 | |
| Source Publication | ASTRONOMY & ASTROPHYSICS
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| ISSN | 0004-6361 |
| Volume | 679Pages:A39 |
| Contribution Rank | 5 |
| Abstract | Context. Protonated hydrogen cyanide, HCNH+, plays a fundamental role in astrochemistry because it is an intermediary in gas-phase ion-neutral reactions within cold molecular clouds. However, the impact of the environment on the chemistry of HCNH+ remains poorly understood.Aims. We aim to study HCNH+, HCN, and HNC, as well as two other chemically related ions, HCO+ and N2H+, in different star formation regions in order to investigate how the environment influences the chemistry of HCNH+.Methods. With the IRAM 30 m and APEX 12 m telescopes, we carried out HCNH+, (HCN)-C-13, (HNC)-C-13, (HCO+)-C-13, and N2H+ imaging observations toward two dark clouds, the Serpens filament and Serpens South, both of which harbor sites of star formation that include protostellar objects and regions that are quiescent.Results. We report the first robust distribution of HCNH+ in the Serpens filament and in Serpens South. Our data suggest that HCNH+ is abundant in cold and quiescent regions but is deficient in active star-forming regions. The observed HCNH+ fractional abundances relative to H-2 range from 3.1 x 10(-11) in protostellar cores to 5.9 x 10(-10) in prestellar cores, and the HCNH+ abundance generally decreases with increasing H-2 column density, which suggests that HCNH+ coevolves with cloud cores. Our observations and modeling results suggest that the abundance of HCNH+ in cold molecular clouds is strongly dependent on the H-2 number density. The decrease in the abundance of HCNH+ is caused by the fact that its main precursors (e.g., HCN and HNC) undergo freeze-out as the number density of H-2 increases. However, current chemical models cannot explain other observed trends, such as the fact that the abundance of HCNH+ shows an anticorrelation with that of HCN and HNC but a positive correlation with that of N2H+ in the southern part of Serpens South's northern clump. This indicates that additional chemical pathways have to be invoked for the formation of HCNH+ via molecules such as N-2 in regions in which HCN and HNC freeze out.Conclusions. Both the fact that HCNH+ is most abundant in molecular cores prior to gravitational collapse and the fact that low-J HCNH+ transitions have very low H-2 critical densities make this molecular ion an excellent probe of pristine molecular gas. |
| Keyword | ISM: clouds radio lines: ISM astrochemistry ISM: molecules ISM: abundances |
| DOI | 10.1051/0004-6361/202347409 |
| Indexed By | SCI |
| Language | 英语 |
| WOS Keyword | HCN/HNC ABUNDANCE RATIO ; STAR-FORMING REGIONS ; AQUILA RIFT ; DARK CLOUDS ; PHASE CHEMISTRY ; DIPOLE-MOMENT ; DENSE CORES ; LINE SURVEY ; SERPENS ; HCN |
| Funding Project | National Natural Science Foundation of China (NSFC) ; Chinese Academy of Sciences President's International Fellowship Initiative ; USRA[12041305] ; USRA[11873094] ; Natural Science Foundation of Xinjiang Uygur Autonomous Region[2022VMA0018] ; Tianshan Talent Program of Xinjiang Uygur Autonomous Region[08-0038] ; Chinese Academy of Sciences Light of West China Program[2022D01E06] ; European Research Council[2022TSYCLJ0005] ; National Radio Astronomy Observatory, USA[xbzg-zdsys-202212] ; European Union[811363] ; [101004719] |
| WOS Research Area | Astronomy & Astrophysics |
| WOS Subject | Astronomy & Astrophysics |
| WOS ID | WOS:001101087500006 |
| Publisher | EDP SCIENCES S A |
| Funding Organization | National Natural Science Foundation of China (NSFC) ; Chinese Academy of Sciences President's International Fellowship Initiative ; USRA ; Natural Science Foundation of Xinjiang Uygur Autonomous Region ; Tianshan Talent Program of Xinjiang Uygur Autonomous Region ; Chinese Academy of Sciences Light of West China Program ; European Research Council ; National Radio Astronomy Observatory, USA ; European Union |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/5626 |
| Collection | 射电天文研究室_恒星形成与演化研究团组 射电天文研究室 |
| Corresponding Author | Gong, Y. |
| Affiliation | 1.Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany 2.Chinese Acad Sci, Purple Mt Observ, 10 Yuanhua Rd, Nanjing 210023, Peoples R China 3.Univ Sci & Technol China, Sch Astron & Space Sci, 96 JinZhai Rd, Hefei 230026, Peoples R China 4.King Abdulaziz Univ, Fac Sci, Astron Dept, POB 80203, Jeddah 21589, Saudi Arabia 5.Chinese Acad Sci, Xinjiang Astron Observ, 150 Sci 1 St, Urumqi 830011, Xinjiang, Peoples R China 6.Johns Hopkins Univ, William H Miller III Department Phys & Astron 3, 3400 North Charles St, Baltimore, MD 21218 USA 7.Guangxi Univ, Dept Phys, Guangxi Key Lab Relativist Astrophys, 100 Daxuedong Rd, Nanning 530004, Peoples R China 8.Zhejiang Lab, Res Ctr Intelligent Comp Platforms, Hangzhou 311100, Peoples R China 9.Univ Rennes, IPR Inst Phys Rennes UMR 6251, CNRS, F-35000 Rennes, France 10.Inst Nacl Astrofis Opt & Electr, Apartado Postal 51 & 216, Puebla 72000, Mexico 11.Chinese Acad Sci, Key Lab Radio Astron, 150 Sci 1 St, Urumqi 830011, Peoples R China 12.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 13.Ctr Astrophys Harvard & Smithsonian, 60 Garden St, Cambridge, MA 02138 USA 14.Natl Radio Astron Observ, 1003 Lopezville Rd, Socorro, NM 87801 USA 15.Chinese Acad Sci, Natl Astron Observ, 20A Datun Rd, Beijing 100101, Peoples R China |
| Recommended Citation GB/T 7714 | Gong, Y.,Du, F. J.,Henkel, C.,et al. Protonated hydrogen cyanide as a tracer of pristine molecular gas[J]. ASTRONOMY & ASTROPHYSICS,2023,679:A39. |
| APA | Gong, Y..,Du, F. J..,Henkel, C..,Jacob, A. M..,Belloche, A..,...&Liu, S..(2023).Protonated hydrogen cyanide as a tracer of pristine molecular gas.ASTRONOMY & ASTROPHYSICS,679,A39. |
| MLA | Gong, Y.,et al."Protonated hydrogen cyanide as a tracer of pristine molecular gas".ASTRONOMY & ASTROPHYSICS 679(2023):A39. |
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| Gong-2023-Protonated（13448KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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