Issue |
A&A
Volume 677, September 2023
|
|
---|---|---|
Article Number | A80 | |
Number of page(s) | 14 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361/202345893 | |
Published online | 08 September 2023 |
ALMA and VLBA views on the outflow associated with an O-type protostar in G26.50+0.28
1
Max-Planck-Institut für Radioastronomie,
Auf dem Hügel 69,
53121
Bonn, Germany
e-mail: gwu@mpifr-bonn.mpg.de
2
Xinjiang Astronomical Observatory,
CAS 150, Science 1-Street Urumqi,
Xinjiang
830011, PR China
3
Astronomy Department, King Abdulaziz University,
PO Box 80203,
Jeddah
21589, Saudi Arabia
4
Purple Mountain Observatory, CAS,
No. 8 Yuanhua Road, Qixia District,
Nanjing
210034, PR China
5
School of Astronomy and Space Science, Nanjing University,
163 Xianlin Avenue,
Nanjing
210023, PR China
6
Shanghai Astronomical Observatory, Chinese Academy of Sciences,
80 Nandan Road,
Shanghai
200030, PR China
Received:
11
January
2023
Accepted:
10
July
2023
Protostellar jets and outflows are essential ingredients of the star formation process. A better understanding of this phenomenon is important in its own right as well as for many fundamental aspects of star formation. Jets and outflows associated with O-type protostars are rarely studied with observations reaching the close vicinity of the protostars. In this work, we report high-resolution ALMA and VLBA observations to reveal a clear and consistent picture of an outflow associated with an O-type protostar candidate in the G26.50+0.28 region. These observations reveal, for the first time, a collimated jet located in the middle of the outflow cavity. The jet is found to be perpendicular to an elongated disk/toroid and its velocity gradient. The collimated jet appears to show a small amplitude (α≈0°.06) counterclockwise precession, when looking along the blueshifted jet axis from the strongest continuum source MM1, with a precession length of 0.22 pc. The inclination of the jet is likely to be very low (≈8°), which makes it a promising target to study its transverse morphologies and kinematics. However, no clear evidence of jet rotation is found in the ALMA and VLBA observations. The three-dimensional velocities of the water maser spots appear to show the same absolute speed with respect to different opening angles, suggesting the jet winds may be launched in a relatively small region. This favors the X-wind model, that is, jets are launched in a small area near the inner disk edge.
Key words: ISM: individual objects: G26.50+0.28/IRAS 18360-0537 / ISM: jets and outflows / stars: formation / masers / radio lines: ISM
© The Authors 2023
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.
This article is published in open access under the Subscribe to Open model.
Open Access funding provided by Max Planck Society.
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