Modeling the Extragalactic Background Light and the Cosmic Star Formation History

Abstract

We present an updated model for the extragalactic background light (EBL) from stars and dust, over wavelengths ≈0.1–1000 μm. This model uses accurate theoretical stellar spectra, and tracks the evolution of star formation, stellar mass density, metallicity, and interstellar dust extinction and emission in the universe with redshift. Dust emission components are treated self-consistently, with stellar light absorbed by dust reradiated in the infrared as three blackbody components. We fit our model, with free parameters associated with star formation rate and dust extinction and emission, to a wide variety of data: luminosity density, stellar mass density, and dust extinction data from galaxy surveys; and γ-ray absorption optical depth data from γ-ray telescopes. Our results strongly constraint the star formation rate density and dust photon escape fraction of the universe out to redshift z = 10, about 90% of the history of the universe. We find our model result is, in some cases, below lower limits on the z = 0 EBL intensity, and below some low-z γ-ray absorption measurements.

Possible Evidence for Lorentz Invariance Violation in Gamma-Ray Burst 221009A

“…The universe is expected to be extremely opaque to photons at these energies for the redshift of GRB 221009A, due to γγ interactions with background radiation fields. One finds absorption optical depths τ γγ (18 TeV)  10 for all recent EBL models (e.g., Franceschini et al 2008;Razzaque et al 2009;Finke et al 2010Finke et al , 2022Kneiske & Dole 2010;Dominguez et al 2011;Helgason & Kashlinsky 2012;Stecker et al 2012;Scully et al 2014;Khaire & Srianand 2015;Stecker et al 2016;Franceschini & Rodighiero 2017;Andrews et al 2018;Khaire & Srianand 2019;Saldana-Lopez et al 2021) Several ways have been proposed to avoid the γ-ray absorption at these energies; one is that the high-energy photons may avoid attenuation by converting to axion-like particles (ALPs) in the presence of magnetic fields in the GRB jet, host galaxy, or intergalactic space (Baktash et al 2022;Carenza & Marsh 2022;Galanti et al 2022bGalanti et al , 2022aNakagawa et al 2022;Troitsky 2022;Zhang & Ma 2022). Another is through Lorentz invariance violation (LIV), as suggested by Dzhappuev et al (2022), Baktash et al (2022), and Li & Ma (2022).…”

“…we use the EBL model from Finke et al (2022) and the CMB, when appropriate. Following Jacob & Piran (2008) and Biteau & Williams (2015), to include the effects of LIV on γγ opacity, we allow ( )…”

Simultaneously unveiling the EBL and intrinsic spectral parameters of gamma-ray sources with Hamiltonian Monte Carlo

“…Recently, an updated EBL model based on F10 was published [55] (Finke et al 2022) and it is also included in figure 8. It takes improved stellar models, a different parametrization of the star formation rate, and incorporates metallicity and dust extinction evolution with redshift.…”

Probing Lorentz Invariance Violation with Absorption of Astrophysical γ-Rays by Solar Photons

“…This is demonstrated in Figure 4 for EBL absorption. Here we plot the EBL absorption optical depth from the model of Finke et al (2022) with no LIV, and with LIV for various values of ξ. Here the LIV effect is computed as described by Finke & Razzaque (2023), following the formulation of Jacob & Piran (2008).…”

“…Another effect is the modification of the threshold for pair production from photon-photon interactions, i.e., the process γ + γ → e + + e − . Subluminal LIV can be constrained with this process with γ-rays from extragalactic sources (such as blazars and GRBs), which are absorbed by ultraviolet through farinfrared photons from the extragalactic background light (EBL; e.g., Nikishov 1962;Gould & Schréder 1967a;Fazio & Stecker 1970;Franceschini et al 2008;Razzaque et al 2009;Finke et al 2010Finke et al , 2022Kneiske & Dole 2010;Domínguez et al 2011;Helgason & Kashlinsky 2012;Stecker et al 2012Stecker et al , 2016Scully et al 2014;Khaire & Srianand 2015;Franceschini & Rodighiero 2017;Andrews et al 2018;Khaire & Srianand 2019;Saldana-Lopez et al 2021). The EBL is the integrated background light from all the stars that have existed in the observable Universe, either through direct emission, or through absorption and reradiation by dust.…”