J/ApJ/737/L20       Metallicity dependent star formation rates       (Dib, 2011)
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Feedback-regulated star formation: implications for the Kennicutt-Schmidt law.
    Dib S.
   <Astrophys. J., 737, L20 (2011)>
   =2011ApJ...737L..20D
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ADC_Keywords: Models ; Interstellar medium
Keywords: galaxies: ISM - ISM: clouds - ISM: molecules - stars: formation

Abstract:
    We derive a metallicity-dependent relation between the surface density
    of the star formation rate ({Sigma}_SFR_) and the gas surface density
    ({Sigma}_g_) in a feedback-regulated model of star formation in
    galactic disks. In this model, star formation occurs in
    gravitationally bound protocluster clumps embedded in larger giant
    molecular clouds with the protocluster clump mass function following a
    power-law function with a slope of -2. Metallicity-dependent feedback
    is generated by the winds of OB stars (M>~5M_{sun}_) that form in the
    clumps. The quenching of star formation in clumps of decreasing
    metallicity occurs at later epochs due to weaker wind luminosities,
    thus resulting in higher final star formation efficiencies (SFE_exp_).
    By combining SFE_exp_ with the timescales on which gas expulsion
    occurs, we derive the metallicity-dependent SFR per unit time in this
    model as a function of {Sigma}_g_. This is combined with the molecular
    gas fraction in order to derive the global dependence of {Sigma}_SFR_
    on {Sigma}_g_. The model reproduces very well the observed star
    formation laws extending from low gas surface densities up to the
    starburst regime. Furthermore, our results show a dependence of
    {Sigma}_SFR_ on metallicity over the entire range of gas surface
    densities in contrast to other models and can also explain part of the
    scatter in the observations. We provide a tabulated form of the star
    formation laws that can easily be incorporated into numerical
    simulations or semi-analytical models of galaxy formation and
    evolution.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table1.dat     70      276   Data for the metallicity dependent star formation
                             laws
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See also:
   J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)

Byte-by-byte Description of file: table1.dat
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   Bytes Format Units        Label    Explanations
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   1- 10  F10.7 [Msun/pc2]   logSig.g Log of gas surface density log{Sigma}_gas_
  12- 22  E11.5 Msun/yr/kpc2 SFR0.1   Star formation rate surface density
                                      for gas at Z=0.1 Z_Sun_
  24- 34  E11.5 Msun/yr/kpc2 SFR0.3   Star formation rate surface density
                                      for gas at Z=0.3 Z_Sun_
  36- 46  E11.5 Msun/yr/kpc2 SFR0.5   Star formation rate surface density
                                      for gas at Z=0.5 Z_Sun_
  48- 58  E11.5 Msun/yr/kpc2 SFR1.0   Star formation rate surface density
                                      for gas at Z=1 Z_Sun_
  60- 70  E11.5 Msun/yr/kpc2 SFR2.0   Star formation rate surface density
                                      for gas at Z=2 Z_Sun_
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History:
    From electronic version of the journal

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(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    10-Jan-2013