Spatial distributions and kinematics of shocked and ionized gas in M17
Abstract
Massive stars are formed in molecular clouds, and produce H II regions when they evolve onto the main sequence. The expansion of H II region can both suppress and promote star formation in the vicinity. M17 H II region is a giant cometary H II region near many massive clumps containing starless and protostellar sources. It is an appropriate target to study the effect of feedback from previously formed massive stars on the nearby star-forming environments. Observations of SiO 2-1, HCO+ 1-0, H13CO+ 1-0, HC3N 10-9, and H41 α lines are performed toward M17 H II region with ambient candidates of massive clumps. In the observations, the widespread shocked gas surrounding M17 H II region is detected: it probably originates from the collision between the expanding ionized gas and the ambient neutral medium. Some massive clumps are found in the overlap region of the shock and dense-gas tracing lines while the central velocities of shocked and high-density gases are similar. This suggests that part of massive clumps are located in the shell of H II region, and may be formed from the accumulated neutral materials in the shell. In addition, by comparing the observations towards M17 H II region with the simulation of cometary H II region, we infer the presence of one or more massive stars travelling at supersonic velocity with respect to the natal molecular cloud in the H II region.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2023
- DOI:
- 10.1093/mnras/stad996
- arXiv:
- arXiv:2306.12128
- Bibcode:
- 2023MNRAS.522..503Z
- Keywords:
-
- stars: formation;
- stars: massive;
- H II regions;
- ISM: structure;
- star: winds;
- outflows;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 13 pages, 11 figures