Issue |
A&A
Volume 633, January 2020
|
|
---|---|---|
Article Number | A126 | |
Number of page(s) | 16 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361/201936432 | |
Published online | 22 January 2020 |
The dynamically young outflow of the Class 0 protostar Cha-MMS1★
1
Max-Planck-Institut für Radioastronomie,
Auf dem Hügel 69,
53121
Bonn,
Germany
e-mail: labusch@mpifr-bonn.mpg.de
2
Argelander-Institut für Astronomie, Universität Bonn,
Auf dem Hügel 71,
53121
Bonn,
Germany
3
LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Université,
UPMC Univ. Paris 06,
75014
Paris,
France
4
Université Grenoble Alpes, CNRS, IPAG,
38000
Grenoble,
France
5
AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité,
91191
Gif-sur-Yvette,
France
6
Centre de Recherche Astrophysique de Lyon UMR5574, ENS de Lyon, Univ. Lyon1, CNRS, Université de Lyon,
69007
Lyon,
France
Received:
1
August
2019
Accepted:
18
November
2019
Context. On the basis of its low luminosity, its chemical composition, and the absence of a large-scale outflow, the dense core Cha-MMS1 located in the Chamaeleon I molecular cloud, was proposed a decade ago as a candidate for a first hydrostatic core (FHSC).
Aims. Our goal is to test this hypothesis by searching for a slow, compact outflow driven by Cha-MMS1 that would match the predictions of magnetohydrodynamic simulations for this short phase of star formation.
Methods. We used the Atacama Large Millimetre/submillimetre Array to map Cha-MMS1 at high angular resolution in CO 3–2 and 13CO 3–2 as well as in continuum emission.
Results. We report the detection of a bipolar outflow emanating from the central core, along a (projected) direction roughly parallel to the filament in which Cha-MMS1 is embedded and perpendicular to the large-scale magnetic field. The morphology of the outflow indicates that its axis lies close to the plane of the sky. We measure velocities corrected for inclination of more than 90 km s−1, which is clearly incompatible with the expected properties of an FHSC outflow. Several properties of the outflow are determined and compared to previous studies of Class 0 and Class I protostars. The outflow of Cha-MMS1 has a much smaller momentum force than the outflows of other Class 0 protostars. In addition, we find a dynamical age of 200–3000 yr indicating that Cha-MMS1 might be one of the youngest ever observed Class 0 protostars. While the existence of the outflow suggests the presence of a disk, no disk is detected in continuum emission and we derive an upper limit of 55 au to its radius.
Conclusions. We conclude that Cha-MMS1 has already gone through the FHSC phase and is a young Class 0 protostar, but it has not yet brought its outflow to full power.
Key words: stars: formation / stars: protostars / stars: jets / ISM: jets and outflows
The reduced datacubes are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/633/A126
© L. A. Busch et al. 2020
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://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.