Free Access

Fig. 3.

image

Download original image

Radio spectral index, α (where Sν ∝ να), versus spectroscopic redshift for the 35 LOFAR detected quasars overlapping with FIRST. Upper limits are given for the quasars not detected in FIRST and a lower limit is given for the quasar not detected in LoTSS. The median spectral index for the quasar sample is both determined by stacking all 93 quasars (red) and only the 35 S/N > 2 detected ones (grey) in the overlapping LoTSS and FIRST area. The red and grey areas give the errors on the median spectral indices, which are the 16th and 84th percentiles determined by bootstrapping.

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.