Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T21:28:54.841Z Has data issue: false hasContentIssue false
  • English
  • Français

The diagnostic power of radio spectra from star-forming galaxies

Published online by Cambridge University Press:  10 June 2020

Eric J. Murphy Open the ORCID record for Eric J. Murphy [Opens in a new window]
Eric J. Murphy*
Affiliation:
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22901, U.S.A. email: emurphy@nrao.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Radio continuum emission from galaxies is powered by a combination of distinct physical processes, each providing unique diagnostic information. Over frequencies spanning ∼ 1–120 GHz, radio spectra of star-forming galaxies are primarily comprised of: (1) non-thermal synchrotron emission powered by accelerated cosmic-ray electrons/positrons; (2) free-free emission from young massive star-forming (H ii) regions; (3) anomalous microwave emission, which is a dominant, but completely unconstrained, foreground in cosmic microwave background experiments; and (4) cold, thermal dust emission that accounts for most of the dust and total mass content in the interstellar medium in galaxies. In this proceeding, we discuss these key energetic processes that contribute to the radio emission from star-forming galaxies, with an emphasis on frequencies ≳30 GHz, where current investigations of star formation within nearby galaxies show that the free-free emission begins to dominate over non-thermal synchrotron emission. We also discuss how planned radio facilities that will access these frequencies, such as a next-generation Very Large Array (ngVLA), will be transformative to our understanding of the star formation process in galaxies.

Keywords

Star FormationRadio Continuum
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 15 , Symposium S341: Challenges in Panchromatic Modelling with Next Generation Facilities , November 2019 , pp. 177 - 186
Copyright
© International Astronomical Union 2020

References

Barcos-Muñoz, L., Leroy, A. K., Evans, A. S., et al. 2015, ApJ, 799, 1010.1088/0004-637X/799/1/10CrossRefGoogle Scholar
Barger, A., Kohno, K., Murphy, E. J., et al. 2018, ASP Monograph 7, Title of the Book, ed. E. Murphy (San Francisco, CA: ASP)Google Scholar
Balser, D. S., Anderson, L. D., Bania, T. M., et al. 2018, ASP Monograph 7, Title of the Book, ed. Murphy, E. (San Francisco, CA: ASP)Google Scholar
BICEP2/Keck Collaboration, Planck Collaboration, Ade, P. A. R., et al. 2015, Physical Review Letters, 114, 10130110.1103/PhysRevLett.114.101301CrossRefGoogle Scholar
Bot, C., Ysard, N., Paradis, D., et al. 2010, A&A, 523, A20Google Scholar
Clemens, M. S., Vega, O., Bressan, A., et al. 2008, A&A, 477, 95Google Scholar
Clemens, M. S., Scaife, A., Vega, O., & Bressan, A. 2010, MNRAS, 405, 887Google Scholar
Condon, J. J. & Yin, Q. F. 1990, ApJ, 357, 9710.1086/168894CrossRefGoogle Scholar
Condon, J. J., Huang, Z.-P., Yin, Q. F., & Thuan, T. X. 1991, ApJ, 378, 6510.1086/170407CrossRefGoogle Scholar
Condon, J. J. 1992, ARA&A, 30, 57510.1146/annurev.aa.30.090192.003043CrossRefGoogle Scholar
Dame, T. M., Hartmann, D., & Thaddeus, P. 2001, ApJ, 547, 79210.1086/318388CrossRefGoogle Scholar
Dickinson, C., Ali-Haïmoud, Y., Barr, A., et al. 2018, NewAR, 80, 1Google Scholar
Draine, B. T. & Lazarian, A. 1998, ApJL, 494, L1910.1086/311167CrossRefGoogle Scholar
Draine, B. T. & Lazarian, A. 1999, ApJ, 512, 74010.1086/306809CrossRefGoogle Scholar
Erickson, W. C. 1957, ApJ, 126, 48010.1086/146421CrossRefGoogle Scholar
Heiles, C., Reach, W. T., & Koo, B.-C. 1988, ApJ, 332, 31310.1086/166657CrossRefGoogle Scholar
Hensley, B., Murphy, E., & Staguhn, J. 2015, MNRAS, 449, 80910.1093/mnras/stv287CrossRefGoogle Scholar
Hensley, B. S., Draine, B. T., & Meisner, A. M. 2016, ApJ, 827, 4510.3847/0004-637X/827/1/45CrossRefGoogle Scholar
Hensley, B. S. & Draine, B. T. 2017, ApJ, 836, 17910.3847/1538-4357/aa5c37CrossRefGoogle Scholar
Klein, U. & Graeve, R. 1986, A&A, 161, 155Google Scholar
Klein, U., Wielebinski, R., & Morsi, H. W. 1988, A&A, 190, 41Google Scholar
Kennicutt, R. C. Jr., Armus, L., Bendo, G., et al. 2003, PASP, 115, 92810.1086/376941CrossRefGoogle Scholar
Kennicutt, R. C. Jr, Lee, J. C., Funes, J. G., et al. 2008, ApJS, 178, 247–27910.1086/590058CrossRefGoogle Scholar
Kennicutt, R. C., Calzetti, D., Aniano, G., et al. 2011, PASP, 123, 134710.1086/663818CrossRefGoogle Scholar
Kobulnicky, H. A. & Johnson, K. E. 1999, ApJ, 527, 15410.1086/308075CrossRefGoogle Scholar
Kogut, A., Banday, A. J., Bennett, C. L., et al. 1996, ApJ, 460, 110.1086/176947CrossRefGoogle Scholar
Koyama, K., Petre, R., Gotthelf, E. V, et al. 1995, Nature, 378, 25510.1038/378255a0CrossRefGoogle Scholar
Leroy, A. K., Evans, A. S., Momjian, E., et al. 2011, ApJL, 739, L2510.1088/2041-8205/739/1/L25CrossRefGoogle Scholar
Leitch, E. M., Readhead, A. C. S., Pearson, T. J., & Myers, S. T. 1997, ApJL, 486, L2310.1086/310823CrossRefGoogle Scholar
Linden, S. T., Murphy, E. J., Dong, D., et al. 2020, ApJS, submittedGoogle Scholar
Mezger, P. G. & Henderson, A. P. 1967, ApJ, 147, 47110.1086/149030CrossRefGoogle Scholar
Murphy, E. J., Helou, G., Condon, J. J., et al. 2010a, ApJL, 709, L10810.1088/2041-8205/709/2/L108CrossRefGoogle Scholar
Murphy, E. J., Condon, J. J., Schinnerer, E., et al. 2011, ApJ, 737, 6710.1088/0004-637X/737/2/67CrossRefGoogle Scholar
Murphy, E. J., Bremseth, J., Mason, B. S., et al. 2012, ApJ, 761, 9710.1088/0004-637X/761/2/97CrossRefGoogle Scholar
Murphy, E. J. 2013, ApJ, 777, 5810.1088/0004-637X/777/1/58CrossRefGoogle Scholar
Murphy, E. J., Dong, D., Leroy, A. K., et al. 2015, ApJ, 813, 11810.1088/0004-637X/813/2/118CrossRefGoogle Scholar
Murphy, E. J., Momjian, E., Condon, J. J., et al. 2017, ApJ, 839, 3510.3847/1538-4357/aa62fdCrossRefGoogle Scholar
Murphy, E. J., Dong, D., Momjian, E., et al. 2018a, ApJS, 234, 2410.3847/1538-4365/aa99d7CrossRefGoogle Scholar
Murphy, E. J., Linden, S. T., Dong, D., et al. 2018b, ApJ, 862, 2010.3847/1538-4357/aac5f5CrossRefGoogle Scholar
Murphy, T., Cohen, M., Ekers, R. D., et al. 2010b, MNRAS, 405, 1560Google Scholar
Niklas, S., Klein, U., & Wielebinski, R. 1997, A&A, 322, 19Google Scholar
Peel, M. W., Dickinson, C., Davies, R. D., Clements, D. L., & Beswick, R. J. 2011, MNRAS, 416, L9910.1111/j.1745-3933.2011.01108.xCrossRefGoogle Scholar
Planck, Collaboration, Ade, P. A. R., Aghanim, N., et al. 2011, A&A, 536, A20Google Scholar
Planck, Collaboration, Adam, R., Ade, P. A. R., et al. 2016, A&A, 586, A133Google Scholar
Scaife, A. M. M., Nikolic, B., Green, D. A., et al. 2010, MNRAS, 406, L4510.1111/j.1745-3933.2010.00878.xCrossRefGoogle Scholar
Scoville, N., Sheth, K., Aussel, H., et al. 2016, ApJ, 820, 8310.3847/0004-637X/820/2/83CrossRefGoogle Scholar
Selina, R. and Murphy, E. J., 2017, ngVLA Memo #17Google Scholar
Socrates, A., Davis, S. W., & Ramirez-Ruiz, E. 2008, ApJ, 687, 202–21510.1086/590046CrossRefGoogle Scholar
Tabatabaei, F. S., Minguez, P., Prieto, M. A., & Fernández-Ontiveros, J. A. 2018, Nature Astronomy, 2, 8310.1038/s41550-017-0298-7CrossRefGoogle Scholar
Turner, J. L. & Ho, P. T. P. 1983, ApJL, 268, L7910.1086/184033CrossRefGoogle Scholar
Turner, J. L. & Ho, P. T. P. 1985, ApJL, 299, L7710.1086/184584CrossRefGoogle Scholar
Turner, J. L. & Ho, P. T. P. 1994, ApJ, 421, 12210.1086/173631CrossRefGoogle Scholar
Turner, J. L., Ho, P. T. P., & Beck, S. C. 1998, AJ, 116, 121210.1086/300485CrossRefGoogle Scholar