Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency

Okezuonu Patrick Chinedu; Ogwo Jemima Ngozi

doi:doi:10.11648/j.ijass.20210903.12

| Peer-Reviewed

Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency

Okezuonu Patrick Chinedu, Ogwo Jemima Ngozi

Published in International Journal of Astrophysics and Space Science (Volume 9, Issue 3)

Received: 11 October 2021 Accepted: 5 November 2021 Published: 24 November 2021

Views: Downloads:

Download PDF

Share This Article

Twitter
Linked In
Facebook

Abstract

The overall efficiency with which Milky Way Giant Molecular Clouds (GMCs) is forming stars was determined by deriving an equation using density of cloud (i.e. stellar density/ total cloud density), which is the core parameter that determines star formation other than the mass of cloud, and comparing with mass (i.e. stellar mass/ total gas mass) as was propounded by previous researchers, to ascertain the reasons the observed star formation efficiency of Milky Way Giant Molecular Clouds (ϵ_GMC) is low. This will aid understanding the physical factors behind the formation of stars from interstellar gas and develop a predictive theory of star formation and evolution of galaxies. A total of 191 star formation complexes-giant molecular cloud (SFC-GMC) complexes was used in estimating the following cloud parameters: density as 93.8218 solar mass/parsec squared, average stellar density as 2.67872 solar mass/parsec squared, average luminosity as 9.87E24 solar luminosity, average effective temperature as 498,647 solar temperature, average stellar radius as 51.4522 parsec and average cloud radius as 325507 parsec as well as the total mass in stars M_⋆ harbored by the individual clouds (20,831 solar mass), which was inferred from Wilkinson Microwave Anisotropy probe (WMAP) free-free. Finally, the overall efficiency with which Milky Way Giant Molecular Clouds is forming star gave 0.0289573 which is less than the previous estimate as 0.030849, showing that not all the masses of the cloud were present at the end of the star formation, and this reduction in mass are caused by magnetic field, supersonic turbulence, self-regulation and unbound states of its internal structure, which are the reasons the observed star formation efficiencies are low.

Published in	International Journal of Astrophysics and Space Science (Volume 9, Issue 3)
DOI	10.11648/j.ijass.20210903.12
Page(s)	45-50
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2021. Published by Science Publishing Group

Keywords

Galaxies, Star Formation Efficiency, Cloud Density, Stellar Mass, Gas Mass

References

[1]	Burkhart B. & Philip M., (2019), the self-gravitating gas fraction and the critical density for star formation, arXiv: 805.11104v3 [astro-ph. GA].
[2]	Clark, P. C., Bonnell I. A., (2004). Star formation in transient molecular clouds MNRAS, 347, L36.
[3]	Clark, P. C., Bonnell I. A., Zinnecker H., Bate M. R., (2005). Star formation in unbound giant molecular clouds: the origin of OB associations MNRAS, 359.
[4]	Clark, P. C.; Bonnell I. A. and Klessen R. S., (2008). The star formation efficiency and its relation to variations in the initial mass function MNRAS, 386, 3-10.
[5]	Crutcher, R. M. (1999). Magnetic fields in molecular clouds: observations confront theory. Astrophys. J. 520, 706–713. doi: 10.1086/307483.
[6]	Crutcher, R. M., Wandelt, B., Heiles, C., Falgarone, E., and Troland, T. H. (2010). Magnetic fields in interstellar clouds from zeeman observations: inference of total field strengths by Bayesian analysis. Astrophys. J. 725, 466–479. doi: 10.1088/0004-637X/725/1/466.
[7]	Cunningham A. J., Krumholz M. R., Mckee C. F., 2018, The effects of magnetic fields and protostellar feedback on low-mass cluster formation MNRAS 476, 771-792.
[8]	Dame, T. M., Hartmann, D., & Thaddeus, P. (2001). The Milky Way in molecular clouds: a new complete CO survey ApJ, 547, 792.
[9]	Elmegreen, B. G., (2002). Star Formation from Galaxies to Globules ApJ, 577, 206.
[10]	Grudic M. Y., Hopkins P. F., Faucher-Gigu ´ ere C.-A., Quataert E., Murray ` N., Keres D., 2018, ˇ MNRAS, 475, 3511
[11]	Grudic M. Y., Hopkins P. F., Lee E. J., Murray N., Faucher-Giguere C. – A., Johnson L. C., 2019, MNRAS, 488 1501–1518.
[12]	Hennebelle P. and Inutsuka S. (2019) The Role of Magnetic Field in Molecular Cloud Formation and Evolution. Front. Astron. Space Sci. 6: 5. doi: 10.3389/fspas.2019.00005.
[13]	Krumholz M. R and Federrath C (2019) The Role of Magnetic Fields in Setting the Star Formation Rate and the Initial Mass Function. Front. Astron. Space Sci. 6: 7. doi: 10.3389/fspas.2019.00007.
[14]	Kravtsov, A. V., (2003). On the origin of the global Schmidt law of star formation ApJ, 590, L1.
[15]	Lee, E. J., Murray N., Rahman M., (2012). Milky way star-forming complexes and the turbulent motion of the Galaxy's molecular gas ApJ, 752, 146.
[16]	Lee, E. J., Miville-Deschenes M.-A., Murray N. W., (2016). Observational evidence of dynamic star formation rate in milky way giant molecular clouds ApJ, 833, 229.
[17]	Li H., Vogelsberger M., Marinacci F., Gnedin O. Y., (2019), MNRAS 487, 364-380.
[18]	Matzner, C. D., & McKee, C. F., (2002) Efficiencies of Low-Mass Star and Star Cluster. ApJ, 545: 364–378.
[19]	Mckee C. F., Ostriker E. C., (2019), Theory of star formation. Annu. Rev. Astro. Astrophys.
[20]	Mo, H. J.; Vanden Bosch, F. C. & White, S. D. M., (2010). Galaxy formation and evolution, MNRAS, 284, 192.
[21]	Murray, N., & Rahman, M. (2010). Star formation in massive clusters via the Wilkinson Microwave Anisotropy Probe and the Spitzer Glimpse survey ApJ, 709, 424.
[22]	Murray, N. (2011). Star formation efficiencies and lifetimes of giant molecular clouds in the Milky Way ApJ, 729, 133.
[23]	Plume, R., Jaffe D. T., Evans II N. J. Martin-Pintado J. AND Gomez-Gonzalez J. (1997). Dense gas and star formation: Characteristics of cloud cores associated with water masers ApJ 476: 730–749.
[24]	Stahler, S. W. & Palla, F. (2004). The Formation of Stars. Weinheim: Wiley-VCH. ISBN 3-527-40559-3.
[25]	Williams, J. P., & McKee, C. F. (1997). The Galactic distribution of OB associations in molecular clouds. ApJ, 476, 166.

Cite This Article

Plain Text BibTeX RIS

APA Style

Okezuonu Patrick Chinedu, Ogwo Jemima Ngozi. (2021). Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency. International Journal of Astrophysics and Space Science, 9(3), 45-50. https://doi.org/10.11648/j.ijass.20210903.12

Copy | Download

ACS Style

Okezuonu Patrick Chinedu; Ogwo Jemima Ngozi. Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency. Int. J. Astrophys. Space Sci. 2021, 9(3), 45-50. doi: 10.11648/j.ijass.20210903.12

Copy | Download

AMA Style

Okezuonu Patrick Chinedu, Ogwo Jemima Ngozi. Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency. Int J Astrophys Space Sci. 2021;9(3):45-50. doi: 10.11648/j.ijass.20210903.12

Copy | Download

@article{10.11648/j.ijass.20210903.12,
  author = {Okezuonu Patrick Chinedu and Ogwo Jemima Ngozi},
  title = {Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency},
  journal = {International Journal of Astrophysics and Space Science},
  volume = {9},
  number = {3},
  pages = {45-50},
  doi = {10.11648/j.ijass.20210903.12},
  url = {https://doi.org/10.11648/j.ijass.20210903.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijass.20210903.12},
  abstract = {The overall efficiency with which Milky Way Giant Molecular Clouds (GMCs) is forming stars was determined by deriving an equation using density of cloud (i.e. stellar density/ total cloud density), which is the core parameter that determines star formation other than the mass of cloud, and comparing with mass (i.e. stellar mass/ total gas mass) as was propounded by previous researchers, to ascertain the reasons the observed star formation efficiency of Milky Way Giant Molecular Clouds (ϵ_GMC) is low. This will aid understanding the physical factors behind the formation of stars from interstellar gas and develop a predictive theory of star formation and evolution of galaxies. A total of 191 star formation complexes-giant molecular cloud (SFC-GMC) complexes was used in estimating the following cloud parameters: density as 93.8218 solar mass/parsec squared, average stellar density as 2.67872 solar mass/parsec squared, average luminosity as 9.87E24 solar luminosity, average effective temperature as 498,647 solar temperature, average stellar radius as 51.4522 parsec and average cloud radius as 325507 parsec as well as the total mass in stars M_⋆ harbored by the individual clouds (20,831 solar mass), which was inferred from Wilkinson Microwave Anisotropy probe (WMAP) free-free. Finally, the overall efficiency with which Milky Way Giant Molecular Clouds is forming star gave 0.0289573 which is less than the previous estimate as 0.030849, showing that not all the masses of the cloud were present at the end of the star formation, and this reduction in mass are caused by magnetic field, supersonic turbulence, self-regulation and unbound states of its internal structure, which are the reasons the observed star formation efficiencies are low.},
 year = {2021}
}

Copy | Download

TY  - JOUR
T1  - Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency
AU  - Okezuonu Patrick Chinedu
AU  - Ogwo Jemima Ngozi
Y1  - 2021/11/24
PY  - 2021
N1  - https://doi.org/10.11648/j.ijass.20210903.12
DO  - 10.11648/j.ijass.20210903.12
T2  - International Journal of Astrophysics and Space Science
JF  - International Journal of Astrophysics and Space Science
JO  - International Journal of Astrophysics and Space Science
SP  - 45
EP  - 50
PB  - Science Publishing Group
SN  - 2376-7022
UR  - https://doi.org/10.11648/j.ijass.20210903.12
AB  - The overall efficiency with which Milky Way Giant Molecular Clouds (GMCs) is forming stars was determined by deriving an equation using density of cloud (i.e. stellar density/ total cloud density), which is the core parameter that determines star formation other than the mass of cloud, and comparing with mass (i.e. stellar mass/ total gas mass) as was propounded by previous researchers, to ascertain the reasons the observed star formation efficiency of Milky Way Giant Molecular Clouds (ϵ_GMC) is low. This will aid understanding the physical factors behind the formation of stars from interstellar gas and develop a predictive theory of star formation and evolution of galaxies. A total of 191 star formation complexes-giant molecular cloud (SFC-GMC) complexes was used in estimating the following cloud parameters: density as 93.8218 solar mass/parsec squared, average stellar density as 2.67872 solar mass/parsec squared, average luminosity as 9.87E24 solar luminosity, average effective temperature as 498,647 solar temperature, average stellar radius as 51.4522 parsec and average cloud radius as 325507 parsec as well as the total mass in stars M_⋆ harbored by the individual clouds (20,831 solar mass), which was inferred from Wilkinson Microwave Anisotropy probe (WMAP) free-free. Finally, the overall efficiency with which Milky Way Giant Molecular Clouds is forming star gave 0.0289573 which is less than the previous estimate as 0.030849, showing that not all the masses of the cloud were present at the end of the star formation, and this reduction in mass are caused by magnetic field, supersonic turbulence, self-regulation and unbound states of its internal structure, which are the reasons the observed star formation efficiencies are low.
VL  - 9
IS  - 3
ER  -

Copy | Download

Author Information

Okezuonu Patrick Chinedu

Department of Industrial Physics, Faculty of Physical Science, Abia State University, Uturu, Nigeria
Ogwo Jemima Ngozi

Department of Industrial Physics, Faculty of Physical Science, Abia State University, Uturu, Nigeria

Download PDF

Sections

Plain Text BibTeX RIS

APA Style

Okezuonu Patrick Chinedu, Ogwo Jemima Ngozi. (2021). Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency. International Journal of Astrophysics and Space Science, 9(3), 45-50. https://doi.org/10.11648/j.ijass.20210903.12

Copy | Download

ACS Style

Okezuonu Patrick Chinedu; Ogwo Jemima Ngozi. Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency. Int. J. Astrophys. Space Sci. 2021, 9(3), 45-50. doi: 10.11648/j.ijass.20210903.12

Copy | Download

AMA Style

Okezuonu Patrick Chinedu, Ogwo Jemima Ngozi. Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency. Int J Astrophys Space Sci. 2021;9(3):45-50. doi: 10.11648/j.ijass.20210903.12

Copy | Download

@article{10.11648/j.ijass.20210903.12,
  author = {Okezuonu Patrick Chinedu and Ogwo Jemima Ngozi},
  title = {Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency},
  journal = {International Journal of Astrophysics and Space Science},
  volume = {9},
  number = {3},
  pages = {45-50},
  doi = {10.11648/j.ijass.20210903.12},
  url = {https://doi.org/10.11648/j.ijass.20210903.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijass.20210903.12},
  abstract = {The overall efficiency with which Milky Way Giant Molecular Clouds (GMCs) is forming stars was determined by deriving an equation using density of cloud (i.e. stellar density/ total cloud density), which is the core parameter that determines star formation other than the mass of cloud, and comparing with mass (i.e. stellar mass/ total gas mass) as was propounded by previous researchers, to ascertain the reasons the observed star formation efficiency of Milky Way Giant Molecular Clouds (ϵ_GMC) is low. This will aid understanding the physical factors behind the formation of stars from interstellar gas and develop a predictive theory of star formation and evolution of galaxies. A total of 191 star formation complexes-giant molecular cloud (SFC-GMC) complexes was used in estimating the following cloud parameters: density as 93.8218 solar mass/parsec squared, average stellar density as 2.67872 solar mass/parsec squared, average luminosity as 9.87E24 solar luminosity, average effective temperature as 498,647 solar temperature, average stellar radius as 51.4522 parsec and average cloud radius as 325507 parsec as well as the total mass in stars M_⋆ harbored by the individual clouds (20,831 solar mass), which was inferred from Wilkinson Microwave Anisotropy probe (WMAP) free-free. Finally, the overall efficiency with which Milky Way Giant Molecular Clouds is forming star gave 0.0289573 which is less than the previous estimate as 0.030849, showing that not all the masses of the cloud were present at the end of the star formation, and this reduction in mass are caused by magnetic field, supersonic turbulence, self-regulation and unbound states of its internal structure, which are the reasons the observed star formation efficiencies are low.},
 year = {2021}
}

Copy | Download

TY  - JOUR
T1  - Density, Alternative Determinant of Star Formation Efficiency of the Milky Way GMCs: Core Reason for Low Star Formation Efficiency
AU  - Okezuonu Patrick Chinedu
AU  - Ogwo Jemima Ngozi
Y1  - 2021/11/24
PY  - 2021
N1  - https://doi.org/10.11648/j.ijass.20210903.12
DO  - 10.11648/j.ijass.20210903.12
T2  - International Journal of Astrophysics and Space Science
JF  - International Journal of Astrophysics and Space Science
JO  - International Journal of Astrophysics and Space Science
SP  - 45
EP  - 50
PB  - Science Publishing Group
SN  - 2376-7022
UR  - https://doi.org/10.11648/j.ijass.20210903.12
AB  - The overall efficiency with which Milky Way Giant Molecular Clouds (GMCs) is forming stars was determined by deriving an equation using density of cloud (i.e. stellar density/ total cloud density), which is the core parameter that determines star formation other than the mass of cloud, and comparing with mass (i.e. stellar mass/ total gas mass) as was propounded by previous researchers, to ascertain the reasons the observed star formation efficiency of Milky Way Giant Molecular Clouds (ϵ_GMC) is low. This will aid understanding the physical factors behind the formation of stars from interstellar gas and develop a predictive theory of star formation and evolution of galaxies. A total of 191 star formation complexes-giant molecular cloud (SFC-GMC) complexes was used in estimating the following cloud parameters: density as 93.8218 solar mass/parsec squared, average stellar density as 2.67872 solar mass/parsec squared, average luminosity as 9.87E24 solar luminosity, average effective temperature as 498,647 solar temperature, average stellar radius as 51.4522 parsec and average cloud radius as 325507 parsec as well as the total mass in stars M_⋆ harbored by the individual clouds (20,831 solar mass), which was inferred from Wilkinson Microwave Anisotropy probe (WMAP) free-free. Finally, the overall efficiency with which Milky Way Giant Molecular Clouds is forming star gave 0.0289573 which is less than the previous estimate as 0.030849, showing that not all the masses of the cloud were present at the end of the star formation, and this reduction in mass are caused by magnetic field, supersonic turbulence, self-regulation and unbound states of its internal structure, which are the reasons the observed star formation efficiencies are low.
VL  - 9
IS  - 3
ER  -

Copy | Download