The star formation law at low surface density

Ted K. Wyder, D. Christopher Martin, Tom A. Barlow, Karl Foster, Peter G. Friedman, Patrick Morrissey, Susan G. Neff, James D. Neill, David Schiminovich, Mark Seibert, Luciana Bianchi, José Donas, Timothy M. Heckman, Young-Wook Lee, Barry F. Madore, Bruno Milliard, R. Michael Rich, Alex S. Szalay, Sukyoung Yi

Research output: Contribution to journalArticle

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Abstract

We investigate the nature of the star formation law at low gas surface densities using a sample of 19 low surface brightness (LSB) galaxies with existing HI maps in the literature, UV imaging from the Galaxy Evolution Explorer satellite, and optical images from the Sloan Digital Sky Survey. All of the LSB galaxies have (NUV - r) colors similar to those for higher surface brightness star-forming galaxies of similar luminosity indicating that their average star formation histories are not very different. Based upon four LSB galaxies with both UV and far-infrared (FIR) data, we find FIR/UV ratios significantly less than 1, implying low amounts of internal UV extinction in LSB galaxies. We use the UV images and HI maps to measure the star formation rate (SFR) and hydrogen gas surface density within the same region for all the galaxies. The LSB galaxy star formation rate surface densities lie below the extrapolation of the power law fit to the SFR surface density as a function of the total gas density for higher surface brightness galaxies. Although there is more scatter, the LSB galaxies also lie below a second version of the star formation law in which the SFR surface density is correlated with the gas density divided by the orbital time in the disk. The downturn seen in both star formation laws is consistent with theoretical models that predict lower star formation efficiencies in LSB galaxies due to the declining molecular fraction with decreasing density.

Original languageEnglish
Pages (from-to)1834-1853
Number of pages20
JournalAstrophysical Journal
Volume696
Issue number2
DOIs
Publication statusPublished - 2009 May 10

Fingerprint

star formation
galaxies
brightness
star formation rate
gas density
gas
Explorer satellites
gases
extrapolation
power law
extinction
luminosity
histories
hydrogen
color
stars
orbitals

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Wyder, T. K., Martin, D. C., Barlow, T. A., Foster, K., Friedman, P. G., Morrissey, P., ... Yi, S. (2009). The star formation law at low surface density. Astrophysical Journal, 696(2), 1834-1853. https://doi.org/10.1088/0004-637X/696/2/1834
Wyder, Ted K. ; Martin, D. Christopher ; Barlow, Tom A. ; Foster, Karl ; Friedman, Peter G. ; Morrissey, Patrick ; Neff, Susan G. ; Neill, James D. ; Schiminovich, David ; Seibert, Mark ; Bianchi, Luciana ; Donas, José ; Heckman, Timothy M. ; Lee, Young-Wook ; Madore, Barry F. ; Milliard, Bruno ; Rich, R. Michael ; Szalay, Alex S. ; Yi, Sukyoung. / The star formation law at low surface density. In: Astrophysical Journal. 2009 ; Vol. 696, No. 2. pp. 1834-1853.
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Wyder, TK, Martin, DC, Barlow, TA, Foster, K, Friedman, PG, Morrissey, P, Neff, SG, Neill, JD, Schiminovich, D, Seibert, M, Bianchi, L, Donas, J, Heckman, TM, Lee, Y-W, Madore, BF, Milliard, B, Rich, RM, Szalay, AS & Yi, S 2009, 'The star formation law at low surface density', Astrophysical Journal, vol. 696, no. 2, pp. 1834-1853. https://doi.org/10.1088/0004-637X/696/2/1834

The star formation law at low surface density. / Wyder, Ted K.; Martin, D. Christopher; Barlow, Tom A.; Foster, Karl; Friedman, Peter G.; Morrissey, Patrick; Neff, Susan G.; Neill, James D.; Schiminovich, David; Seibert, Mark; Bianchi, Luciana; Donas, José; Heckman, Timothy M.; Lee, Young-Wook; Madore, Barry F.; Milliard, Bruno; Rich, R. Michael; Szalay, Alex S.; Yi, Sukyoung.

In: Astrophysical Journal, Vol. 696, No. 2, 10.05.2009, p. 1834-1853.

Research output: Contribution to journalArticle

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AU - Wyder, Ted K.

AU - Martin, D. Christopher

AU - Barlow, Tom A.

AU - Foster, Karl

AU - Friedman, Peter G.

AU - Morrissey, Patrick

AU - Neff, Susan G.

AU - Neill, James D.

AU - Schiminovich, David

AU - Seibert, Mark

AU - Bianchi, Luciana

AU - Donas, José

AU - Heckman, Timothy M.

AU - Lee, Young-Wook

AU - Madore, Barry F.

AU - Milliard, Bruno

AU - Rich, R. Michael

AU - Szalay, Alex S.

AU - Yi, Sukyoung

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Wyder TK, Martin DC, Barlow TA, Foster K, Friedman PG, Morrissey P et al. The star formation law at low surface density. Astrophysical Journal. 2009 May 10;696(2):1834-1853. https://doi.org/10.1088/0004-637X/696/2/1834