1 research outputs found
A new derivation of the Hubble constant from -ray attenuation using improved optical depths for the Fermi and CTA era
We present -ray optical-depth calculations from a recently published
extragalactic background light (EBL) model built from multiwavelength galaxy
data from the Hubble Space Telescope Cosmic Assembly Near-Infrared Deep
Extragalactic Legacy Survey (HST/CANDELS). CANDELS gathers one of the deepest
and most complete observations of stellar and dust emissions in galaxies. This
model resulted in a robust derivation of the evolving EBL spectral energy
distribution up to , including the far-infrared peak. Therefore, the
optical depths derived from this model will be useful for determining the
attenuation of -ray photons coming from high-redshift sources, such as
those detected by the Large Area Telescope on board the Fermi Gamma-ray Space
Telescope, and for multi-TeV photons that will be detected from nearby sources
by the future Cherenkov Telescope Array. From these newly calculated optical
depths, we derive the cosmic -ray horizon and also measure the
expansion rate and matter content of the Universe including an assessment of
the impact of the EBL uncertainties. We find km
s Mpc when fixing , and
km s Mpc and , when
exploring these two parameters simultaneously.Comment: 11 pages, 8 figures, 1 tables; Accepted by MNRA