Free Access

Fig. 1


Spectra of the optical counterparts of four BL Lacs in our sample. For each panel, the upper box reports the observed spectrum not corrected for the intervening Galactic absorption, while the lower one shows the same spectrum normalized to its continuum. The main spectral features are labeled in the lower panels, with the intervening Galactic features indicated in the lower part of the box and (if present) the features allowing the redshift measurement marked in the above part of it. The symbol ⊕ indicates atmospheric telluric absorption bands. The TNG spectra have been smoothed using a Gaussian filter with σ = 3 Å.

This figure is made of several images, please see below:

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.