Neural Network Constraints on the Cosmic-Ray Ionization Rate and Other Physical Conditions in NGC 253 with ALCHEMI Measurements of HCN and HNC
文献类型：期刊论文
| 作者 | Behrens,Erica8,13; Mangum,Jeffrey G.8; Viti,Serena15,16,17; Holdship,Jonathan15,17; Huang,Ko-Yun15; Bouvier,Mathilde15; Butterworth,Joshua15; Eibensteiner,Cosima8; Harada,Nanase10,11; Martín,Sergio1,12 |
| 刊名 | The Astrophysical Journal
 |
| 出版日期 | 2024-11-29 |
| 卷号 | 977期号:1页码:38 |
| ISSN号 | 0004-637X |
| DOI | 10.3847/1538-4357/ad85db |
| 产权排序 | 15 |
| 通讯作者 | Behrens, Erica(eb7he@virginia.edu) |
| 英文摘要 | Abstract We use a neural network model and Atacama Large Millimeter/submillimeter Array (ALMA) observations of HCN and HNC to constrain the physical conditions, most notably the cosmic-ray ionization rate (CRIR, ζ), in the Central Molecular Zone (CMZ) of the starburst galaxy NGC 253. Using output from the chemical code UCLCHEM, we train a neural network model to emulate UCLCHEM and derive HCN and HNC molecular abundances from a given set of physical conditions. We combine the neural network with radiative transfer modeling to generate modeled integrated intensities, which we compare to measurements of HCN and HNC from the ALMA Large Program ALCHEMI. Using a Bayesian nested sampling framework, we constrain the CRIR, molecular gas volume and column densities, kinetic temperature, and beam-filling factor across NGC 253's CMZ. The neural network model successfully recovers UCLCHEM molecular abundances with ～3% error and, when used with our Bayesian inference algorithm, increases the parameter-inference speed tenfold. We create images of these physical parameters across NGC 253's CMZ at 50 pc resolution and find that the CRIR, in addition to the other gas parameters, is spatially variable with ζ ～ a few ×10?14 s?1 at r ? 100 pc from the nucleus, increasing to ζ > 10?13 s?1 at its center. These inferred CRIRs are consistent within 1 dex with theoretical predictions based on nonthermal emission. Additionally, the high CRIRs estimated in NGC 253's CMZ can be explained by the large number of cosmic-ray-producing sources as well as a potential suppression of cosmic-ray diffusion near their injection sites. |
| WOS关键词 | CENTRAL MOLECULAR ZONE ; SUPER STAR-CLUSTERS ; LARGE-AREA TELESCOPE ; INTERSTELLAR-MEDIUM ; NONTHERMAL EMISSION ; INFRARED GALAXIES ; GAMMA-RAYS ; MILKY-WAY ; STARBURST ; GAS |
| 资助项目 | European Research Council (ERC) under the European Union[MOPPEX 833460] ; European Research Council (ERC) under the European Union[PID2022-136814NB-I00] ; Spanish Ministry of Science, Innovation and Universities/State Agency of Research[MICIU/AEI/10.13039/501100011033] ; ERDF, UE[MICIU/AEI/10.13039/501100011033] ; ERDF, UE[RYC2020-029387-I] ; ESF ; Consejo Superior de Investigaciones Cientficas (CSIC)[MICIU/AEI/10.13039/501100011033] ; Consejo Superior de Investigaciones Cientficas (CSIC)[20225AT015] ; Consejo Superior de Investigaciones Cientficas (CSIC)[CNS2023-144464] ; European Union NextGenerationEU/PRTR ; JSPS KAKENHI[JP21K03634] ; International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the Universities of Bonn and Cologne[MOST 111-2112-M-001-039] ; Ministry of Science and Technology in Taiwan |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001367800700001 |
| 出版者 | The American Astronomical Society |
| 资助机构 | European Research Council (ERC) under the European Union ; Spanish Ministry of Science, Innovation and Universities/State Agency of Research ; ERDF, UE ; ESF ; Consejo Superior de Investigaciones Cientficas (CSIC) ; European Union NextGenerationEU/PRTR ; JSPS KAKENHI ; International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the Universities of Bonn and Cologne ; Ministry of Science and Technology in Taiwan |
| 源URL | [http://ir.xao.ac.cn/handle/45760611-7/7226]  |
| 专题 | 研究单元未命名 恒星形成与演化研究团组 |
| 作者单位 | 1.European Southern Observatory, Alonso de Córdova, 3107, Vitacura, Santiago 763-0355, Chile 2.Institute of Astronomy and Astrophysics, Academia Sinica, 11F of AS/NTU Astronomy-Mathematics Building, No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan 3.Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala, Sweden 4.Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223–8522, Japan 5.Centro de Astrobiología (CAB), CSIC-INTA, Ctra. de Ajalvir km 4, E28850, Torrejon de Ardoz, Spain 6.New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, USA 7.Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 830011, Urumqi, People's Republic of China 8.National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA 9.National Radio Astronomy Observatory, PO Box O, 1003 Lopezville Road, Socorro, NM 87801, USA 10.National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan |
| 推荐引用方式 GB/T 7714 | Behrens,Erica,Mangum,Jeffrey G.,Viti,Serena,et al. Neural Network Constraints on the Cosmic-Ray Ionization Rate and Other Physical Conditions in NGC 253 with ALCHEMI Measurements of HCN and HNC[J]. The Astrophysical Journal,2024,977(1):38. |
| APA | Behrens,Erica.,Mangum,Jeffrey G..,Viti,Serena.,Holdship,Jonathan.,Huang,Ko-Yun.,...&,.(2024).Neural Network Constraints on the Cosmic-Ray Ionization Rate and Other Physical Conditions in NGC 253 with ALCHEMI Measurements of HCN and HNC.The Astrophysical Journal,977(1),38. |
| MLA | Behrens,Erica,et al."Neural Network Constraints on the Cosmic-Ray Ionization Rate and Other Physical Conditions in NGC 253 with ALCHEMI Measurements of HCN and HNC".The Astrophysical Journal 977.1(2024):38. |
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