Quasars are among the most energetic processes in the Universe.  In this talk I will explore the mid-infrared through ultraviolet spectral energy distributions (SEDs) of 119,652 luminous type 1 quasars with 0.06<z<5.5 using data from Spitzer, WISE, 2MASS, UKIDSS, SDSS, and GALEX. In addition to finding a mean bolometric correction of BC=2.75+-0.40, I investigate the dependency of the mean SED on various parameters, particularly the UV luminosity. Low-luminosity SEDs exhibit a bluer far-UV spectral slope, a redder optical continuum, and less hot dust.

Using a (uniformly selected) subset of these quasars, I also explore the extinction/dust reddening to better understand their intrinsic SEDs. Using optical–UV photometry, I isolate outliers in the color distribution and find them well described by an SMC-like reddening law. A hierarchical Bayesian model was used to find distributions of powerlaw indices and E(B-V) values consistent with both broad absorption line (BAL) and non-BAL samples. The emission and absorption-line properties of both samples showed that quasars with intrinsically red continua have weaker Balmer lines and stronger ionizing spectral lines, the latter indicating a harder continuum in the extreme-UV.

Applying corrections for associated dust, I better determine the intrinsic SEDs and true BCs for the uniformly selected subsample. The SEDs with the most dust extinction are intrinsically brighter and showed more dust emission near 10 microns than the SEDs with less extinction. The bluer SEDs have more hot dust emission and higher BCs, consistent with having hotter accretions disks and/or being viewed closer to edge-on.  Mean SEDs were also made based on the black hole mass and the Eddington fraction.  Quasars with large Eddington fraction and/or large black hole masses have more hot dust and a bluer optical continua, both consistent with a hotter accretion disk.