Blazars are objects in the distant Universe that release large amounts of energy over a short time. Because they are in the distant Universe, their spectra show redshifts that are proportional to their distance. This article compiles data about a set of blazars and calculates Doppler factors that arise from redshifts, helping to advance this field.

http://www.raa-journal.org/raa/index.php/raa/article/view/1655