Massive star formation in the Carina nebula complex and Gum 31 -- I. The Carina nebula complex

Abstract

Herein, we present results from observations of the 12CO (J=1-0), 13CO (J=1-0), and 12CO (J=2-1) emission lines toward the Carina nebula complex (CNC) obtained with the Mopra and NANTEN2 telescopes. We focused on massive-star-forming regions associated with the CNC including the three star clusters Tr14, Tr15, and Tr16, and the isolated WR-star HD92740. We found that the molecular clouds in the CNC are separated into mainly four clouds at velocities -27, -20, -14, and -8 km/s. Their masses are 0.7x10^4Msun, 5.0x10^4 Msun, 1.6x10^4 Msun, and 0.7x10^4 Msun, respectively. Most are likely associated with the star clusters, because of their high 12CO (J=2-1)/12CO (J=1-0) intensity ratios and their correspondence to the Spitzer 8 micron distributions. In addition, these clouds show the observational signatures of cloud--cloud collisions. In particular, there is a V-shaped structure in the position--velocity diagram and a complementary spatial distribution between the -20 km/s cloud and the -14 km/s cloud. Based on these observational signatures, we propose a scenario wherein the formation of massive stars in the clusters was triggered by a collision between the two clouds. By using the path length of the collision and the assumed velocity separation, we estimate the timescale of the collision to be ~1 Myr. This is comparable to the ages of the clusters estimated in previous studies.

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Cited by in corpus (13)

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• Nobeyama 45 m Local Spur CO survey. I. Giant molecular filaments and cluster formation in the Vulpecula OB association
• ALMA Observations of Giant Molecular Clouds in M33 III: Spatially Resolved Features of the Star-Formation Inactive Million-solar-mass Cloud
• A kinematic analysis of the CO clouds toward a reflection nebula NGC 2023 observed with the Nobeyama 45 m telescope; Further evidence for a cloud-cloud collision in the Orion region
• Diffuse $\gamma$-ray emission around the massive star forming region of Carina Nebula Complex
• Giant molecular clouds and their Type classification in M74: Toward understanding star formation and cloud evolution
• The Carina Nebula and Gum 31 molecular complex III: The distribution of the 1-3 GHz radio continuum across the whole nebula
• The formation of the open cluster NGC 602 in the Small Magellanic Cloud triggered by colliding HI flows
• Massive star formation in the Carina nebula complex and Gum 31 -- II. a cloud-cloud collision in Gum 31
• The formation of the HII regions N83 and N84 in the Small Magellanic Cloud triggered by colliding HI flows