ALMA-IMF: XIII. N2H+ kinematic analysis of the intermediate protocluster G353.41
Por:
Álvarez-Gutiérrez R.H., Stutz A.M., Sandoval-Garrido N., Louvet F., Motte F., Galván-Madrid R., Cunningham N., Sanhueza P., Bonfand M., Bontemps S., Gusdorf A., Ginsburg A., Csengeri T., Reyes S.D., Salinas J., Baug T., Bronfman L., Busquet G., Díaz-González D.J., Fernandez-Lopez M., Guzmán A., Koley A., Liu H.-L., Olguin F.A., Valeille-Manet M., Wyrowski F.
Publicada:
1 ene 2024
Resumen:
The ALMA-IMF Large Program provides multi-tracer observations of 15 Galactic massive protoclusters at a matched sensitivity and spatial resolution. We focus on the dense gas kinematics of the G353.41 protocluster traced by N2H+ (1-0), with a spatial resolution of ~0.02 pc. G353.41, at a distance of ~2kpc, is embedded in a larger-scale (~8 pc) filament and has a mass of ~2.5 × 103 M? within 1.3 × 1.3 pc2. We extracted the N2H+ (1-0) isolated line component and decomposed it by fitting up to three Gaussian velocity components. This allows us to identify velocity structures that are either muddled or impossible to identify in the traditional position-velocity diagram. We identify multiple velocity gradients on large (~1 pc) and small scales (~0.2pc). We find good agreement between the N2H+ velocities and the previously reported DCN core velocities, suggesting that cores are kinematically coupled with the dense gas in which they form. We have measured nine converging "V-shaped"velocity gradients (VGs) (~20 km s-1 pc-1) that are well resolved (sizes ~0.1 pc), mostly located in filaments, which are sometimes associated with cores near their point of convergence. We interpret these V-shapes as inflowing gas feeding the regions near cores (the immediate sites of star formation). We estimated the timescales associated with V-shapes as VG-1, and we interpret them as inflow timescales. The average inflow timescale is ~67 kyr, or about twice the free-fall time of cores in the same area (~33 kyr) but substantially shorter than protostar lifetime estimates (~0.5 Myr). We derived mass accretion rates in the range of (0.35-8.77) × 10-4 M? yr-1. This feeding might lead to further filament collapse and the formation of new cores. We suggest that the protocluster is collapsing on large scales, but the velocity signature of collapse is slow compared to pure free-fall. Thus, these data are consistent with a comparatively slow global protocluster contraction under gravity, and faster core formation within, suggesting the formation of multiple generations of stars over the protocluster's lifetime. © The Authors 2024.
Filiaciones:
Álvarez-Gutiérrez R.H.:
Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Stutz A.M.:
Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Sandoval-Garrido N.:
Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Louvet F.:
Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, 38000, France
Motte F.:
Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, 38000, France
Galván-Madrid R.:
Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia, Michoacán, 58089, Mexico
Cunningham N.:
Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, 38000, France
Ska Observatory, Jodrell Bank, Lower Withington, Macclesfield, SK11 9FT, United Kingdom
Sanhueza P.:
National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan
Astronomical Science Program, The Graduate University for Advanced Studies, SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan
Bonfand M.:
Departments of Astronomy, University of Virginia, Charlottesville, 22904, VA, United States
Bontemps S.:
Laboratoire d'Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, Allée Geoffroy Saint-Hilaire, Pessac, 33615, France
Gusdorf A.:
Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, Paris, 75005, France
Observatoire de Paris, PSL University, Sorbonne Université, LERMA, Paris, 75014, France
Ginsburg A.:
Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, 32611, FL, United States
Csengeri T.:
Laboratoire d'Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, Allée Geoffroy Saint-Hilaire, Pessac, 33615, France
Reyes S.D.:
Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Max Planck Institute for Astronomy, Königstuhl 17, Heidelberg, 69117, Germany
Salinas J.:
Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Baug T.:
S. N. Bose National Centre for Basic Sciences, Sector-III, Salt Lake, Kolkata, 700106, India
Bronfman L.:
Astronomy Department, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile
Busquet G.:
Departament de Física Quàntica i Astrofísica (FQA), Universitat de Barcelona (UB), Martí i Franquès 1, Catalonia, Barcelona, 08028, Spain
Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès, 1, Catalonia, Barcelona, 08028, Spain
Institut d'Estudis Espacials de Catalunya (IEEC), Gran Capità, 2-4, Catalonia, Barcelona, 08034, Spain
Díaz-González D.J.:
Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia, Michoacán, 58089, Mexico
Fernandez-Lopez M.:
Instituto Argentino de Radioastronomía (CCT-La Plata, CONICET
Guzmán A.:
Joint ALMA Observatory (JAO), Alonso de Cordova 3107, Vitacura, Santiago, Chile
Koley A.:
Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Liu H.-L.:
School of Physics and Astronomy, Yunnan University, Kunming, 650091, China
Olguin F.A.:
Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu, 30013, Taiwan
Valeille-Manet M.:
Laboratoire d'Astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, Allée Geoffroy Saint-Hilaire, Pessac, 33615, France
Wyrowski F.:
Max-Planck-Institut für Radioastronomie, Auf dem Hü gel 69, Bonn, 53121, Germany
Green Submitted, All Open Access; Green Open Access
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