Constraining the star formation rate with the extragalactic background light

Abstract

The present day spectrum of the extragalactic background light (EBL) in UV, optical, and IR wavelengths is the integral result of multiple astrophysical processes going on throughout the evolution of the Universe. The relevant processes include star formation, stellar evolution, light absorption, and emission by the cosmic dust. The properties of these processes are known with uncertainties, which contribute to the EBL spectrum precision. In this paper, we develop a numerical model of the EBL spectrum while maintaining the explicit dependence on the astrophysical parameters involved. We constructed a Markov Chain in the parameter space by using the likelihood function built with the up-to-date upper and lower bounds on the EBL intensity. The posterior distributions built with the Markov Chain Monte Carlo method are used to determine an allowed range of the individual parameters of the model. Consequently, the star formation rate multiplication factor is constrained in the range 1.01 < C_sfr < 1.69 at 68 per cent C.L. The method also results in the bounds on the lifetime, radius, dust particle density, and opacity of the molecular clouds that have large ambiguity otherwise. It is shown that there is a reasonable agreement between the model and the intensity bounds while the astrophysical parameters of the best-fitting model are close to their estimates from literature.