BoRG graduate student Charlotte Mason (UCSB) has developed a Bayesian framework to account for the magnification bias from gravitational lensing in luminosity functions, and used the BoRG z~8 LF as a test case. Magnification bias can distort the bright end of high redshift LFs so it is important to understand how it affects our results.

The work has been accepted for publication in the Astrophysical Journal.


We find that magnification bias is currently not significant for the luminosity range of galaxies in BoRG: the effect is only significant for the very brightest galaxies, with $$M_{UV}<-22$$. However, we also show that the effect will dominate future wide-area surveys such as Euclid and WFIRST, which will detect the rarest very bright galaxies, so it will be crucial to account for magnification bias in these surveys.