Dense Cloud Formation and Star Formation in a Barred Galaxy

Abstract

We investigate the properties of massive, dense clouds formed in a barred galaxy and their possible relation to star formation, performing a two-dimensional hydrodynamical simulation with the gravitational potential obtained from the 2Mass data from the barred spiral galaxy, M83. Since the environment for cloud formation and evolution in the bar region is expected to be different from that in the spiral arm region, barred galaxies are a good target to study the environmental effects on cloud formation and the subsequent star formation. Our simulation uses for an initial 80 Myr an isothermal flow of non-self gravitating gas in the barred potential, then including radiative cooling, heating and self-gravitation of the gas for the next 40 Myr, during which dense clumps are formed. We identify many cold, dense gas clumps for which the mass is more than $10^4{M}_{\odot }$ (a value corresponding to the molecular clouds) and study the physical properties of these clumps. The relation of the velocity dispersion of the identified clump's internal motion with the clump size is similar to that observed in the molecular clouds of our Galaxy. We find that the virial parameters for clumps in the bar region are larger than that in the spiral arm region. From our numerical results, we estimate star formation in the bar and spiral arm regions by applying the simple model of Krumholtz and McKee (2005). The mean relation between star formation rate and gas surface density agrees well with the observed Kennicutt-Schmidt relation. The SFE in the bar region is $\sim 60$ of the spiral arm region. This trend is consistent with observations of barred galaxies.

9 pages, 16 figures. Accepted for publication in the MNRAS

References in corpus (5)

• Theory of Star Formation
• Star Formation in Disk Galaxies. I. Formation and Evolution of Giant Molecular Clouds via Gravitational Instability and Cloud Collisions
• The formation of molecular clouds in spiral galaxies
• Star Formation in Disk Galaxies. II. The Effect of Star Formation and Photoelectric Heating on the Formation and Evolution of Giant Molecular Clouds
• Star formation efficiency in the Barred Spiral Galaxy NGC 4303

Cited by in corpus (18)

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• The Physical Drivers and Observational Tracers of CO-to-H2 Conversion Factor Variations in Nearby Barred Galaxy Centers
• Environmental dependence of star formation induced by cloud collisions in a barred galaxy
• Wide-field 12CO (J = 1-0) Imaging of the Nearby Barred Galaxy M83 with NMA and Nobeyema 45-m telescope: Molecular Gas Kinematics and Star Formation Along the Bar
• A large amount of diffuse molecular gases in the bar of the strongly barred galaxy NGC1300: Cause of the low star formation efficiency
• Molecular Gas Properties in M83 from CO PDFs
• Constraining the dark matter content of NGC 1291 using hydrodynamic gas response simulations
• CO Multi-line Imaging of Nearby Galaxies (COMING). III. Dynamical effect on molecular gas density and star formation in the barred spiral galaxy NGC 4303
• Properties of giant molecular clouds in the strongly barred galaxy NGC1300
• Star Formation & Dust Heating in the FIR Bright Sources of M83
• Molecular gas and star formation within 12 strong galactic bars observed with IRAM-30m
• Large velocity dispersion of molecular gas in bars of strongly barred galaxies, NGC 1300 and NGC 5383
• Fast cloud-cloud collisions in a strongly barred galaxy: Suppression of massive star formation
• CO(2-1)/CO(1-0) line ratio on $\sim$100 parsec scale in the nearby barred galaxy NGC1300
• Connection among environment, cloud-cloud collision speed, and star formation activity in the strongly barred galaxy NGC1300