Discovering High-$z$ BL Lacs Using Swift/UVOT and SARA Observations with the Dropout Technique
Yong Sheng, K. Imam, A. Kaur, M. Ajello et autres
Measuring spectroscopic redshifts for BL Lacertae (BL Lac) objects, a class of blazar, is challenging because their optical spectrum lacks, or has weak, emission lines ( equivalent width $\leqslant5Å$). In this situation, alternative techniques are necessary for the estimation of distances to …