(A) Stellar mass of the BOSS point source sample as a function of redshift. The black points show the parent sample, and the red points are E+A galaxies. (B) The empirically determined S/N of the continuum measured in two windows adjacent to the Hδ absorption line. The solid black and gray hashed histograms are the S/N distributions for the BOSS point source and the E+A and complementary parent samples, respectively.