Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps
We present SiO J = 2-1 maps of the Sgr B2 molecular cloud, which show shocked gas with a turbulent substructure comprising at least three cavities at velocities of [10, 40] km s(-1) and an arc at velocities of [-20, 10] km s(-1). The spatial anticorrelation of shocked gas at low and high velocities,...
| Autores: | , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Instituto Nacional de Técnica Aeroespacial (INTA) |
| Repositorio: | DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial |
| OAI Identifier: | oai:digital.inta.es:20.500.12666/294 |
| Acceso en línea: | https://academic.oup.com/mnras/article-abstract/499/4/4918/5920233 http://hdl.handle.net/20.500.12666/294 |
| Access Level: | acceso abierto |
| Palabra clave: | Methods: numerical ISM: clouds ISM: molecules Galaxy: centre |
| id |
ES_ff855f0d8be9d7ce8a67f61ed367555c |
|---|---|
| oai_identifier_str |
oai:digital.inta.es:20.500.12666/294 |
| network_acronym_str |
ES |
| network_name_str |
España |
| repository_id_str |
|
| dc.title.none.fl_str_mv |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| title |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| spellingShingle |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps Armijos Abendaño, J. Methods: numerical ISM: clouds ISM: molecules Galaxy: centre |
| title_short |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| title_full |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| title_fullStr |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| title_full_unstemmed |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| title_sort |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission maps |
| dc.creator.none.fl_str_mv |
Armijos Abendaño, J. Banda Barragán, W. E. Martín Pintado, J. Dénes, H. Federrath, C. Requena Torres, Miguel Angel |
| author |
Armijos Abendaño, J. |
| author_facet |
Armijos Abendaño, J. Banda Barragán, W. E. Martín Pintado, J. Dénes, H. Federrath, C. Requena Torres, Miguel Angel |
| author_role |
author |
| author2 |
Banda Barragán, W. E. Martín Pintado, J. Dénes, H. Federrath, C. Requena Torres, Miguel Angel |
| author2_role |
author author author author author |
| dc.contributor.none.fl_str_mv |
Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737 Banda Barragán, W. E. [0000-0002-1960-4870] Denes, H. [0000-0002-9214-8613] Federrath, C. [0000-0002-0706-2306] Deutsche Forschungsgemeinschaft (DFG) Australian Research Council (ARC) |
| dc.subject.none.fl_str_mv |
Methods: numerical ISM: clouds ISM: molecules Galaxy: centre |
| topic |
Methods: numerical ISM: clouds ISM: molecules Galaxy: centre |
| description |
We present SiO J = 2-1 maps of the Sgr B2 molecular cloud, which show shocked gas with a turbulent substructure comprising at least three cavities at velocities of [10, 40] km s(-1) and an arc at velocities of [-20, 10] km s(-1). The spatial anticorrelation of shocked gas at low and high velocities, and the presence of bridging features in position-velocity diagrams suggest that these structures formed in a cloud-cloud collision. Some of the known compact HII regions spatially overlap with sites of strong SiO emission at velocities of [40, 85] km s(-1), and are between or along the edges of SiO gas features at [100, 120] km s(-1), suggesting that the stars responsible for ionizing the compact HII regions formed in compressed gas due to this collision. We find gas densities and kinetic temperatures of the order of n(H2) similar to 10(5) cm(-3) and similar to 30 K, respectively, towards three positions of Sgr B2. The average values of the SiO relative abundances, integrated line intensities, and line widths are similar to 10(-9), similar to 11 K kms(-1), and similar to 31 km s(-1), respectively. These values agree with those obtained with chemical models that mimic grain sputtering by C-type shocks. A comparison of our observations with hydrodynamical simulations shows that a cloud-cloud collision that took place less than or similar to 0.5 Myr ago can explain the density distribution with a mean column density of (N) over bar (H2) greater than or similar to 5 x 10(22) cm(-2), and the morphology and kinematics of shocked gas in different velocity channels. Colliding clouds are efficient at producing internal shocks with velocities similar to 5-50 km s(-1). High-velocity shocks are produced during the early stages of the collision and can readily ignite star formation, while moderate- and low-velocity shocks are important over longer time-scales and can explain the widespread SiO emission in Sgr B2. |
| publishDate |
2020 |
| dc.date.none.fl_str_mv |
2020 2021 2021 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://purl.org/coar/resource_type/c_6501 |
| format |
article |
| status_str |
publishedVersion |
| dc.identifier.none.fl_str_mv |
https://academic.oup.com/mnras/article-abstract/499/4/4918/5920233 http://hdl.handle.net/20.500.12666/294 |
| url |
https://academic.oup.com/mnras/article-abstract/499/4/4918/5920233 http://hdl.handle.net/20.500.12666/294 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.rights.none.fl_str_mv |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess |
| rights_invalid_str_mv |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
| eu_rights_str_mv |
openAccess |
| dc.format.none.fl_str_mv |
application/pdf |
| dc.publisher.none.fl_str_mv |
Oxford Academics: Oxford University Press |
| publisher.none.fl_str_mv |
Oxford Academics: Oxford University Press |
| dc.source.none.fl_str_mv |
reponame:DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial instname:Instituto Nacional de Técnica Aeroespacial (INTA) |
| instname_str |
Instituto Nacional de Técnica Aeroespacial (INTA) |
| reponame_str |
DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial |
| collection |
DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial |
| repository.name.fl_str_mv |
|
| repository.mail.fl_str_mv |
|
| _version_ |
1869425781876195328 |
| spelling |
Structure and kinematics of shocked gas in Sgr B2: further evidence of a cloud–cloud collision from SiO emission mapsArmijos Abendaño, J.Banda Barragán, W. E.Martín Pintado, J.Dénes, H.Federrath, C.Requena Torres, Miguel AngelMethods: numericalISM: cloudsISM: moleculesGalaxy: centreWe present SiO J = 2-1 maps of the Sgr B2 molecular cloud, which show shocked gas with a turbulent substructure comprising at least three cavities at velocities of [10, 40] km s(-1) and an arc at velocities of [-20, 10] km s(-1). The spatial anticorrelation of shocked gas at low and high velocities, and the presence of bridging features in position-velocity diagrams suggest that these structures formed in a cloud-cloud collision. Some of the known compact HII regions spatially overlap with sites of strong SiO emission at velocities of [40, 85] km s(-1), and are between or along the edges of SiO gas features at [100, 120] km s(-1), suggesting that the stars responsible for ionizing the compact HII regions formed in compressed gas due to this collision. We find gas densities and kinetic temperatures of the order of n(H2) similar to 10(5) cm(-3) and similar to 30 K, respectively, towards three positions of Sgr B2. The average values of the SiO relative abundances, integrated line intensities, and line widths are similar to 10(-9), similar to 11 K kms(-1), and similar to 31 km s(-1), respectively. These values agree with those obtained with chemical models that mimic grain sputtering by C-type shocks. A comparison of our observations with hydrodynamical simulations shows that a cloud-cloud collision that took place less than or similar to 0.5 Myr ago can explain the density distribution with a mean column density of (N) over bar (H2) greater than or similar to 5 x 10(22) cm(-2), and the morphology and kinematics of shocked gas in different velocity channels. Colliding clouds are efficient at producing internal shocks with velocities similar to 5-50 km s(-1). High-velocity shocks are produced during the early stages of the collision and can readily ignite star formation, while moderate- and low-velocity shocks are important over longer time-scales and can explain the widespread SiO emission in Sgr B2.We gratefully acknowledge discussions with Andrew Lehmann and Fabien Louvet, and thank the anonymous referee for very helpful and constructive feedback. This work is based on observations carried out under project number 137-14 with the IRAM 30-m telescope. IRAM is supported by INSU, CNRS (France), MPG (Germany), and Instituto Geografico Nacional (IGN, Spain). WBB is supported by the Deutsche Forschungsgemeinschaft (DFG) via grant BR2026125, and by the National Secretariat of Higher Education, Science, Technology, and Innovation of Ecuador, SENESCYT. CF acknowledges funding provided by the Australian Research Council (Discovery Project DP170100603 and Future Fellowship FT180100495), and the Australia-Germany Joint Research Cooperation Scheme (UADAAD). The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project (pn34qu) by providing computing time on the GCS Supercomputer SuperMUC-NG at Leibniz Supercomputing Centre (www.lrz.de).Part of the numerical work presented here was conducted on the Hummel supercomputer at Universitat Hamburg. This work has made use of the pyFC package by A. Y. Wagner (available at https://bitbucket.org/pandante/pyfc) to generate lognormal, fractal clouds for the initial conditions in the simulations, the VisIt visualization software (Childs et al. 2012), the gnuplot program (http://www.gnuplot.info), MATPLOTLIB (Hunter 2007), NUMPY (van der Walt, Colbert & Varoquaux 2011), and ASTROPY, a communitydeveloped core PYTHON package for Astronomy (Astropy Collaboration 2013, 2018; http://www.astropy.org); With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)Peer reviewOxford Academics: Oxford University PressUnidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Banda Barragán, W. E. [0000-0002-1960-4870]Denes, H. [0000-0002-9214-8613]Federrath, C. [0000-0002-0706-2306]Deutsche Forschungsgemeinschaft (DFG)Australian Research Council (ARC)202120212020info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501application/pdfhttps://academic.oup.com/mnras/article-abstract/499/4/4918/5920233http://hdl.handle.net/20.500.12666/294reponame:DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacialinstname:Instituto Nacional de Técnica Aeroespacial (INTA)InglésAttribution 4.0 InternationalCopyright © 2020, © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Societyhttps://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/openAccessoai:digital.inta.es:20.500.12666/2942026-06-23T12:46:37Z |
| score |
15,81155 |