Propagation of Highly Efficient Star Formation in NGC 7000

Abstract

We surveyed the (1,1), (2,2), and (3,3) lines of NH3 and the H2O maser toward the molecular cloud L935 in the extended HII region NGC 7000 with an angular resolution of 1.6' using the Kashima 34-m telescope. We found five clumps in the NH3 emission with a size of 0.2--1 pc and mass of 9--452 M_sun. The molecular gas in these clumps has a similar gas kinetic temperature of 11--15 K and a line width of 1--2 km/s. However, they have different star formation activities such as the concentration of T-Tauri type stars and the association of H2O maser sources. We found that these star formation activities are related to the geometry of the HII region. The clump associated with the T-Tauri type star cluster has a high star formation efficiency of 36--62%. This clump is located near the boundary of the HII region and molecular cloud. Therefore, we suggest that the star formation efficiency increases because of the triggered star formation.

19 pages, 15 figures, accepted for PASJ Vol.63 No.6

References in corpus (3)

• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• The star formation in the L1615/L1616 cometary cloud
• Pre-main sequence stars in the Cepheus flare region

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• Outflows, Dusty Cores, and a Burst of Star Formation in the North America and Pelican Nebulae
• Searching for Molecular Outflows with Support Vector Machines: Dark Cloud Complex in Cygnus
• X-ray survey of the North-America and Pelican star-forming complex (NGC7000/IC5070)
• Ammonia mapping observations toward the Galactic massive star-forming region Sh 2-255 and Sh 2-257
• NH${}_3$ Observations of the S235 Star Forming Region: Dense Gas in Inter-core Bridges
• Ammonia mapping observations of the Galactic infrared bubble N49: Three NH${}_3$ clumps along the molecular filament
• KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Star formation feedback on dense molecular gas in the W33 complex