Friday, August 3, 2012

1208.0489 (Masakazu A. R. Kobayashi et al.)

Revisiting the Cosmic Star Formation History: Caution to the Uncertainties in Dust Correction and Star Formation Rate Conversion    [PDF]

Masakazu A. R. Kobayashi, Yoshiyuki Inoue, Akio K. Inoue
The cosmic star formation rate density (CSFRD) has been observationally investigated out to redshift z ~ 10. However, most of theoretical models for galaxy formation underpredict the CSFRD at z > 1. Since the theoretical models reproduce the observed luminosity function (LF), luminosity densities (LDs), and stellar mass density at each redshift, this inconsistency is not simply implied that theoretical models should incorporate some missing unknown physical processes in galaxy formation. Therefore, we examine the cause of this inconsistency in UV wavelengths by using a mock catalog of galaxies generated by a semi-analytic model of galaxy formation. We find that this inconsistency is due to two observational uncertainties: dust obscuration correction and conversion from UV luminosity to star formation rate (SFR). The methods of obscuration correction and SFR conversion used in observational studies result in the overestimation of CSFRD by ~ 0.1-0.3 dex and ~ 0.1-0.2 dex, respectively, compared to the one directly obtained by our mock catalog. We present new empirical calibrations for dust extinction and conversion from observed UV LF and LD into CSFRD.
View original: http://arxiv.org/abs/1208.0489

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