Journal
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
Volume 73, Issue 4, Pages 880-893Publisher
OXFORD UNIV PRESS
DOI: 10.1093/pasj/psab050
Keywords
ISM: clouds; ISM: kinematics and dynamics; ISM: molecules; stars: formation
Categories
Funding
- National Aeronautics and Space Administration
- Space Telescope Science Institute under U.S. Government [NAG W-2166]
- Japanese Society for the Promotion of Science (JSPS) [15H05694, 25287035, 19H05075, 20H01945]
- Building of Consortia for the Development of Human Resources in Science and Technology of Ministry of Education, Culture, Sports, Science and Technology (MEXT) [01-M10305]
- Grants-in-Aid for Scientific Research [20H01945, 19H05075, 25287035] Funding Source: KAKEN
Ask authors/readers for more resources
The study reveals gas dynamics with two velocity components in NGC 2023, a typical signature of cloud-cloud collision. Compared to neighboring NGC 2024, NGC 2023 shows lower star formation activity, possibly attributed to its lower column density.
We performed fully sampled J = 1-0 line observations of (CO)-C-12 and (CO)-C-13 toward the reflection nebula NGC 2023 using the Nobeyama 45 m telescope. It covered the entire NGC 2023 region with angular and velocity resolutions of 19 '' corresponding to 0.04 pc and 0.33 km s(-1), respectively. We analyzed the data focusing on gas dynamics and revealed two velocity components, each with a mass of similar to 3000 M-circle dot, at radial velocities of 10 and 12 km s(-1). These components show spatially complementary distributions and are connected in velocity, both of which are the typical signatures of cloud-cloud collision (CCC). Although previous studies favored a scheme of triggering by the H parallel to region of IC 434, our results show that the effect of the H parallel to region is limited only to the surface of the molecular cloud, and does not contribute to the entire gas compression and the overall star formation. Comparing the present results with those for neighboring NGC 2024, we find that their active star formation can be explained by a single CCC event. We suggest that the 10 and 12 km s(-1) clouds collided similar to 0.4 Myr ago, which is common to the regions, but triggered the B1.5V-type star HD 37903 as well as similar to 20 low-mass stars in NGC 2023, and similar to 20 OB stars in NGC 2024. The column density in NGC 2023 is two to three times lower than that of NGC 2024, which may result in the different star formation activity suggested by the trend of similar to 50 other CCC-triggered star-forming regions in the literature.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available