A New Measurement of the Hubble Constant and Matter Content of the Universe Using Extragalactic Background Light γ-Ray Attenuation

DOI: 
10.3847/1538-4357/ab4a0e
Publication date: 
01/11/2019
Main author: 
Domínguez, A.
IAA authors: 
Prada, F.
Authors: 
Domínguez, A.;Wojtak, R.;Finke, J.;Ajello, M.;Helgason, K.;Prada, F.;Desai, A.;Paliya, V.;Marcotulli, L.;Hartmann, D. H.
Journal: 
The Astrophysical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
885
Pages: 
137
Abstract: 
The Hubble constant H <SUB>0</SUB> and matter density Ω<SUB> m </SUB> of the universe are measured using the latest γ-ray attenuation results from Fermi-LAT and Cerenkov telescopes. This methodology is based upon the fact that the extragalactic background light supplies opacity for very high energy photons via photon─photon interaction. The amount of γ-ray attenuation along the line of sight depends on the expansion rate and matter content of the universe. This novel strategy results in a value of {H}<SUB>0</SUB>={67.4}<SUB>-6.2</SUB><SUP>+6.0</SUP> km s<SUP>−1</SUP> Mpc<SUP>−1</SUP> and {{{Ω }}}<SUB>m</SUB>={0.14}<SUB>-0.07</SUB><SUP>+0.06</SUP>. These estimates are independent and complementary to those based on the distance ladder, cosmic microwave background (CMB), clustering with weak lensing, and strong lensing data. We also produce a joint likelihood analysis of our results from γ-rays and those from more mature methodologies, excluding the CMB, yielding a combined value of H <SUB>0</SUB> = 66.6 ± 1.6 km s<SUP>−1</SUP> Mpc<SUP>−1</SUP> and Ω<SUB> m </SUB> = 0.29 ± 0.02.
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075301370&doi=10.3847%2f1538-4357%2fab4a0e&partnerID=40&md5=63b1820fbaf1b2a2cd859b7af1d0f338
ADS Bibcode: 
2019ApJ...885..137D
Keywords: 
BL Lacertae objects: general;cosmic background radiation;cosmology: observations;diffuse radiation;Astrophysics - Cosmology and Nongalactic Astrophysics