Free Access

Fig. 6


See Fig. 4 for a general description of the plot. Left panel: additional GRB data from Arcodia et al. (2016) are plotted. Right panel: the distribution of NH (z) with redshift for blazars from this work (blue stars) and for quasars from the literature (black symbols are related to Page et al. 2005; magenta to Nanni et al. 2017; grey to Eitan & Behar 2013; dark green and orange to Shemmer et al. 2006 and Shemmer et al. 2008, respectively; red to Saez et al. 2011; cyan to Yuan et al. 2006; purple to Grupe et al. 2006; lime to Shemmer et al. 2005; dark red to Campana et al. 2015; brown to Ricci et al. 2017; dark orange to Corral et al. 2011). Squares stand for generic non-blazars AGN, while stars for blazars. Error bars were computed within XSPEC at 90% confidence level (Δχ2 = 2.71), as were the upper limits (denoted with arrows below the related symbol).

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.