Probing cosmic opacity with the type Ia supernovae and Hubble parameter

In this paper, we probe the cosmic opacity with the newest Pantheon type Ia supernovae (SNIa) and the observational Hubble parameter ( H(z)) data based on the Λ CDM and w CDM models with or without spatial curvature. In the analysis, we marginalize the likelihood function of SNIa data over the pertinent nuisance parameter ℳ , a combination of the absolute magnitude of SNIa M_B and the Hubble constant H_0 , with a flat prior. Two parameterizations of the optical depth τ (z) associated to the cosmic absorption, namely τ (z)=2ε z and τ (z)= (1+z)^2ε-1 , are adopted. We find that the results are not sensitive to the fiducial cosmological models, the spatial curvature and parameterizations of τ (z) . Moreover, the results from the Pantheon data alone are consistent with a transparent universe ( ε =0 ). And once the H ( z ) data is combined, ε =0 falls within the 68