Volume 649, May 2021
|Number of page(s)||16|
|Section||Interstellar and circumstellar matter|
|Published online||24 May 2021|
Fragmentation and kinematics in high-mass star formation
CORE-extension targeting two very young high-mass star-forming regions★
Max Planck Institute for Astronomy,
2 UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
3 IRAM, 300 rue de la Piscine, Domaine Universitaire de Grenoble, 38406 St.-Martin-d’Hères, France
4 Centre for Astrophysics and Planetary Science, University of Kent, Canterbury, CT2 7NH, UK
5 Chinese Academy of Sciences Key Laboratory of FAST, National Astronomical Observatory of Cina, Datun Road 20, Chaoyang, Bejing 100012, PR China
6 I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
7 INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
8 Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK
9 Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
10 Instituto de Radioastronomıa y Astrofısica, Universidad Nacional Autonoma de Mexico, PO Box 3-72, 58090 Morelia, Michoacan, Mexico
11 School of Physics & Astronomy, E.C. Stoner Building, The University of Leeds, Leeds LS2 9JT, UK
12 Department of Physics and Astronomy, McMaster University, 1280 Main St. W, Hamilton, ON L8S 4M1, Canada
13 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
14 Institute of Astronomy and Astrophysics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
15 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
Accepted: 26 February 2021
Context. The formation of high-mass star-forming regions from their parental gas cloud and the subsequent fragmentation processes lie at the heart of star formation research.
Aims. We aim to study the dynamical and fragmentation properties at very early evolutionary stages of high-mass star formation.
Methods. Employing the NOrthern Extended Millimeter Array and the IRAM 30 m telescope, we observed two young high-mass star-forming regions, ISOSS22478 and ISOSS23053, in the 1.3 mm continuum and spectral line emission at a high angular resolution (~0.8″).
Results. We resolved 29 cores that are mostly located along filament-like structures. Depending on the temperature assumption, these cores follow a mass-size relation of approximately M ∝ r2.0 ± 0.3, corresponding to constant mean column densities. However, with different temperature assumptions, a steeper mass-size relation up to M ∝ r3.0 ± 0.2, which would be more likely to correspond to constant mean volume densities, cannot be ruled out. The correlation of the core masses with their nearest neighbor separations is consistent with thermal Jeans fragmentation. We found hardly any core separations at the spatial resolution limit, indicating that the data resolve the large-scale fragmentation well. Although the kinematics of the two regions appear very different at first sight – multiple velocity components along filaments in ISOSS22478 versus a steep velocity gradient of more than 50 km s−1 pc−1 in ISOSS23053 – the findings can all be explained within the framework of a dynamical cloud collapse scenario.
Conclusions. While our data are consistent with a dynamical cloud collapse scenario and subsequent thermal Jeans fragmentation, the importance of additional environmental properties, such as the magnetization of the gas or external shocks triggering converging gas flows, is nonetheless not as well constrained and would require future investigation.
Key words: stars: formation / ISM: clouds / ISM: kinematics and dynamics / stars: massive / stars: protostars
Data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (126.96.36.199) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/649/A113
© H. Beuther et al. 2021
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Open Access funding provided by Max Planck Society.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.