The extragalactic background light revisited and the cosmic photon–photon opacity (Corrigendum)
University of Padova, Physics and Astronomy Department,
Vicolo Osservatorio 3,
Accepted: 29 March 2018
Key words: cosmic background radiation / diffuse radiation / gamma rays: galaxies / BL Lacertae objects: general / errata, addenda
For some unexplained reasons, all tables in the Franceschini & Rodighiero (2017) paper have been mixed up. Tables 1–3 reported there were identical to those published in Franceschini et al. (2008). We report here in Tables 1, 2, and 4 the corresponding correct values in terms of photon proper number densities and photon–photon optical depths as a function of photon energy.
We also took this occasion to add a new table (Table 3) including the predicted extragalactic background light values at redshifts between 2 and 3.5, as requested by some readers of the Franceschini & Rodighiero (2017) paper.
Both photon number densities and photon–photon optical depths are calculated including the contributions of the cosmic microwave background assumed as a black-body with T = 2.728 K. Except for the numerical values in the tables, all the rest of the Franceschini & Rodighiero (2017) paper is unaffected by the problem.
Photon proper number density as a function of redshift (1).
Photon proper number density as a function of redshift (2).
Photon proper number density as a function of redshift (3).
Photon–photon optical depth as a function of energy and redshift.
We thank Jonathan Biteau, Barbara Biasuzzi, and Christoph Wendel for useful comments and criticisms.
© ESO 2018