Revisiting the Cosmic Star Formation History: Caution on the Uncertainties in Dust Correction and Star Formation Rate Conversion

TL;DR

This paper investigates discrepancies in cosmic star formation rate density estimates at high redshift, attributing them to observational uncertainties in dust correction and UV-to-SFR conversion, and proposes new empirical calibrations.

Contribution

It identifies key observational uncertainties causing overestimations in CSFRD and provides new empirical calibrations to improve accuracy.

Findings

Dust correction overestimates CSFRD by 0.1-0.3 dex.

UV-to-SFR conversion overestimates CSFRD by 0.1-0.2 dex.

Proposes new empirical calibrations for dust attenuation and SFR conversion.

Abstract

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 functions (LFs), luminosity densities (LDs), and stellar mass density at each redshift, this inconsistency does not simply imply that theoretical models should incorporate some missing unknown physical processes in galaxy formation. Here, 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 for correction of obscuration 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 results obtained directly from our mock catalog. We present new empirical calibrations for dust attenuation and conversion from observed UV LFs and LDs into CSFRD.