Infrared/optical energy distributions of high-redshift quasars

Measurements at 1.2, 1.6, and 2.2 μm have been combined with visual spectrophotometry of 21 quasars having redshifts z ≥2.66. The primary result of this study is that the rest frame visual/ultraviolet continua of the high-redshift quasars are well described by a sum of a power-law continuum with slope ~ - 0.4 and a 3000 Å bump. The rest frame visual/ultraviolet continua of these quasars are quite similar to that of 3C 273, the archetype of low-redshift quasars. There do not appear to be any significant visual/ultraviolet properties distinguishing high-redshift quasars selected via visual or radio techniques