Free Access

Fig. 15

image

Comparison of the UV emission line intensities in PG 0043+039 (upper panel) with respect to a composite HST/COS spectrum of 22 AGN (Shull et al. 2012, lower panel). We combined the two ultraviolet spectra of PG 0043+039 taken with the HST in the years 2013 and 1991. The UV line and continuum intensities increased by a factor of 1.8 between these two observations. We multiplied the UV spectral flux taken in 1991 with this factor to match the UV observations taken in 2013. The continua of both spectra are indicated as brown lines.

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.