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Star Formation in Self-Gravitating Molecular Cloud: The Critical Mass and the Core Accretion Rate

DOI: 10.4236/wjm.2020.105005, PP. 53-67

Keywords: Star Formation, Molecular Cloud, Critical Mass, Core Accretion

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Abstract:

Understanding how stars form in molecular clouds is one of the ongoing research areas in astrophysics. Star formation is the fundamental process to which our current understanding remains incomplete due to the complexity of the physics that drives their formation within molecular clouds. In this article theoretical modelling of the lowest possible mass of the cloud needed for collapse and the core accretion rate has been presented for the molecular cloud collapsing under its gravity. In many of previous studies the critical mass of star forming cloud under its gravity has been modelled using kinetic energy and gravitational potential energy. However, we test the effect of thermodynamic efficiency factor together with other physical processes in describing the critical mass, and controlling or triggering the rate of mass falling onto the central core. Assuming that, the ratio of radiation luminosity to gravitational energy released per unit time of the collapsing MC is less than unity. Following this conceptual framework we have formulated the critical mass and the core accretion rate of the self-gravitating molecular cloud.

References

[1]  Ward-Thompson, D. and Whitworth, A.P. (2011) An Introduction to Star Formation. Cambridge University Press, Cambridge.
[2]  Blitz, L. (1988) Large Molecular-Cloud Complexes. In: Wolsten, R.D., Ed., Millimetre and Submillimetre Astronomy, Springer, Berlin, 269-280.
https://doi.org/10.1007/978-94-009-3019-3_10
[3]  Blitz, L. (1991) Star Forming Giant Molecular Clouds. In: Lada, C.J. and Kylafis, N.D., Eds., The Physics of Star Formation and Early Stellar Evolution, Kluwer, Dordrecht, 3-34.
https://doi.org/10.1007/978-94-011-3642-6_1
[4]  Bertram, et al. (2016) Synthetic Observations of Molecular Clouds in a Galactic Centre Environment I. Studying Maps of Column Density and Integrated Intensity. MNRAS, 455, 3763-3778.
https://doi.org/10.1093/mnras/stv2619
[5]  Burrows, A., Hubbard, W.B., Lunine, J.I. and Liebert, J. (2001) The Theory of Brown Dwarfs and Extrasolar Giant Planets. Reviews of Modern Physics, 73, 719-765.
https://doi.org/10.1103/RevModPhys.73.719
[6]  Crowther, P.A., et al. (2010) The R136 Star Cluster Hosts Several Stars Whose Individual Masses Greatly Exceed the Accepted 150Msolar Stellar Mass Limit. MNRAS, 408, 731-751.
[7]  Kroupa, P. (2002) The Initial Mass Function of Stars: Evidence for Uniformity in Variable Systems. Science, 295, 82-91.
https://doi.org/10.1126/science.1067524
[8]  Girichidis (2016) Launching Cosmic-Ray-Driven Outflows from the Magnetized Interstellar Medium. The Astrophysical Journal Letters, 816, L19.
https://doi.org/10.3847/2041-8205/816/2/L19
[9]  Mac Low, M.-M., Smith, M.D., Klessen, R.S. and Burkert, A. (1998) The Decay of Supersonic and Super-Alfvénic Turbulence in Star-Forming Clouds. Astrophysics and Space Science, 261, 195-196.
https://doi.org/10.1023/A:1002036113496
[10]  Mac Low, M.-M. and Klessen, R.S. (2004) Control of Star Formation by Supersonic Turbulence. Reviews of Modern Physics, 76, 125-194.
https://doi.org/10.1103/RevModPhys.76.125
[11]  Ballesteros-Paredes, J., Gazol, A., Kim, J., Klessen, R.S., Jappsen, A.-K., et al. (2006) The Mass Spectra of Cores in Turbulent Molecular Clouds and Implications for the Initial Mass Function. The Astrophysical Journal, 637, 384-391.
https://doi.org/10.1086/498228
[12]  Whitworth, A. (1979) The Erosion and Dispersal of Massive Molecular Clouds by Young Stars. Monthly Notices of the Royal Astronomical Society, 186, 59-67.
https://doi.org/10.1093/mnras/186.1.59
[13]  Franco, J., Shore, S.N. and Tenorio-Tagle, G. (1994) On the Massive Star-Forming Capacity of Molecular Clouds. Astrophysical Journal, 436, 795.
https://doi.org/10.1086/174955
[14]  Walch, S., Whitworth, A.P., Bisbas, T.G., Wünsch, R. and Hubber, D.A. (2013) Clumps and Triggered Star Formation in Ionized Molecular Clouds. Monthly Notices of the Royal Astronomical Society, 435, 917-927.
https://doi.org/10.1093/mnras/stt1115
[15]  Elmegreen, B.G. and Lada, C.J. (1977) Sequential Formation of Subgroups in OB Associations. Astrophysical Journal, 214, 725-741.
https://doi.org/10.1086/155302
[16]  Hosokawa, T. and Inutsuka, S.I. (2006) Dynamical Expansion of Ionization and Dissociation Front around a Massive Star: A Starburst Mechanism. Astrophysical Journal, 648, L131.
https://doi.org/10.1086/507887
[17]  Fukui, Y., et al. (2014) Molecular Clouds toward the Super Star Cluster NGC 3603; Possible Evidence for a Cloud-Cloud Collision in Triggering the Cluster Formation. Astrophysical Journal, 780, 36.
[18]  Kumssa, G.M. and Tessema, S.B. (2019) Low Mass to Intermediate-Mass Star-Forming Hydrostatic Cores in Self-Gravitating Molecular Cloud. Astronomische Nachrichten, 340, 705-793.
https://doi.org/10.1002/asna.201913543

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