| Title: |
Shock-induced HCNH+ abundance enhancement in the heart of the starburst galaxy NGC 253 unveiled by ALCHEMI |
| Authors: |
Gong, Y.; Henkel, C.; Bop, C, T; Mangum, J. G.; Behrens, E.; Du, F, J; Zhang, S.B.; Martin, S.; Menten, K. M.; Harada, N; Bouvier, M.; Tang, X. D.; Tanaka, K.; Viti, S; Yan, Y.T.; Yang, W.; Mao, R. Q.; Quan, D, H |
| Contributors: |
Chinese Academy of Sciences Nanjing Branch; Max-Planck-Institut für Radioastronomie (MPIFR); Institut de Physique de Rennes (IPR); Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS); Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM); Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST); Nantes Université - pôle Sciences et technologie; Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie; Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ); National Radio Astronomy Observatory (NRAO); University of Virginia; Atacama Large Millimeter/submillimeter Array (ALMA); European Southern Observatory (ESO); The Graduate University for Advanced Studies Tokyo (SOKENDAI); National Astronomical Observatory of Japan (NAOJ); Universiteit Leiden = Leiden University; Keio University Tokyo = Keiō Gijuku Daigaku = 慶應義塾大学; Rheinische Friedrich-Wilhelms-Universität Bonn; University College London UCL (UCL); Nanjing University (NJU); Purple Mountain Observatory; Zhejiang Lab Hangzhou; We acknowledge the ALMA staff for their assistance with our observations. Y.G. is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, Grant No. XDB0800301. C.H. acknowledges support by the Chinese Academy of Sciences President’s International Fellowship Initiative under grant No. 2025PVA0048. We also acknowledge financial support from the European Research Council (Consolidator Grant COLLEXISM, Grant Agreement No. 811363) and the support from CEA/GENCI for granting us access to the TGCC/IRENE supercomputer under the A0110413001 project. F.J.D. is supported by National Key R&D Program of China grant 2023YFA1608000 and NSFC grant 12041305. S.V and M.B acknowledge the support from the European Research Council (ERC) Advanced Grant MOPPEX 833460. X.D.T. acknowledges the support of the National Key R&D Program of China under grant No. 2023YFA1608002, the Chinese Academy of Sciences (CAS) “Light of West China” Program under grant No. xbzg-zdsys-202212, the Tianshan Talent Program of Xinjiang Uygur Autonomous Region under grant No. 2022TSY- CLJ0005, and the Natural Science Foundation of Xinjiang Uygur Autonomous Region under grant No. 2022D01E06. W.Y. acknowledges the support from the National Natural Science Foundation of China (12403027), China Postdoctoral Science Foundation (2024M751376), and Jiangsu Funding Programme for Excellent Postdoctoral Talent (2024ZB347). This research has made use of spectroscopic and collisional data from the EMAA database (https://emaa.osug.frandhttps://dx.doi.org/10.17178/EMAA). EMAA is supported by the Observatoire des Sciences de l’Univers de Grenoble (OSUG). This research has made use of NASA’s Astrophysics Data System. This work also made use of the Cube Analysis and Rendering Tool for Astronomy (CARTA) software (Comrie 2021) and Python libraries including Astropy (https://www.astropy.org/, Astropy Collaboration 2013), NumPy (https://www.numpy.org/, van der Walt 2011), SciPy (https://www.scipy.org/, Jones 2001), Matplotlib (https://matplotlib.org/, Hunter 2007). This article makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.00161.L and ADS/JAO.ALMA#2018.1.00162.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSTC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. During the review process, we were deeply saddened by the passing of our esteemed colleague, Prof. Karl M. Menten, whose contributions to this work and to the field will always be remembered. We thank the anonymous referee for the helpful comments that improved this manuscript. |
| Source: |
ISSN: 0004-6361. |
| Publisher Information: |
CCSD; EDP Sciences |
| Publication Year: |
2025 |
| Collection: |
Université de Nantes: HAL-UNIV-NANTES |
| Subject Terms: |
ISM: individual objects: NGC 253; radio lines: ISM; ISM: molecules; ISM: clouds; [PHYS]Physics [physics] |
| Description: |
International audience ; Context. Understanding the chemistry of molecular clouds is pivotal to elucidate star formation and galaxy evolution. As one of the important molecular ions, HCNH+ plays an important role in this chemistry. Yet, its behavior and significance under extreme conditions, such as in the central molecular zones (CMZs) of external galaxies, are still largely unexplored. Aims. We aim to reveal the physical and chemical properties of the CMZ in the starburst galaxy NGC 253 with multiple HCNH+ transitions to shed light on the molecule's behavior under the extreme physical conditions of a starburst. Methods. We employed molecular line data including results for four rotational transitions of HCNH+ from the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI) large program to investigate underlying physical and chemical processes. Results. Despite weak intensities, HCNH+ emission is widespread throughout NGC 253's CMZ, which suggests that this molecular ion can effectively trace large-scale structures within molecular clouds. Using the quantum mechanical coupled states' approximation, we computed rate coefficients for collisions of HCNH+ with para-H-2 and ortho-H(2 )at kinetic temperatures up to 500 K. Using these coefficients in a non-local-thermodynamic-equilibrium (non-LTE) modeling framework and employing a Monte Carlo Markov chain analysis, we find that HCNH+ emission originates from regions with H-2 number densities of similar to 102.80-10(3.55) cm(-3), establishing HCNH+ as a tracer of low-density environments. Our analysis reveals that most of the HCNH+ abundances in the CMZ of NGC 253 are higher than all values reported in the Milky Way. We perform static, photodissociation region, and shock modeling, and found that recurrent shocks could potentially account for the elevated HCNH+ abundances observed in this CMZ. Conclusions. We propose that the unexpectedly high HCNH+ abundances may result from chemical enhancement, primarily driven by the elevated gas ... |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
https://doi.org/10.5281/zenodo.14959763 |
| DOI: |
10.1051/0004-6361/202452835 |
| Availability: |
https://hal.science/hal-05080104; https://hal.science/hal-05080104v2/document; https://hal.science/hal-05080104v2/file/aa52835-24.pdf; https://doi.org/10.1051/0004-6361/202452835 |
| Rights: |
https://creativecommons.org/licenses/by/4.0/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.ABA83951 |
| Database: |
BASE |