THE NEXT GENERATION ATLAS OF QUASAR SPECTRAL ENERGY DISTRIBUTIONS FROM RADIO TO X-RAYS

Abstract

We have produced the next generation of quasar spectral energy distributions\n(SEDs), essentially updating the work of Elvis et al. (1994) by using\nhigh-quality data obtained with several space and ground-based telescopes,\nincluding NASA's Great Observatories. We present an atlas of SEDs of 85\noptically bright, non-blazar quasars over the electromagnetic spectrum from\nradio to X-rays. The heterogeneous sample includes 27 radio-quiet and 58\nradio-loud quasars. Most objects have quasi-simultaneous ultraviolet-optical\nspectroscopic data, supplemented with some far-ultraviolet spectra, and more\nthan half also have Spitzer mid-infrared IRS spectra. The X-ray spectral\nparameters are collected from the literature where available. The radio,\nfar-infrared, and near-infrared photometric data are also obtained from either\nthe literature or new observations. We construct composite spectral energy\ndistributions for radio-loud and radio-quiet objects and compare these to those\nof Elvis et al., finding that ours have similar overall shapes, but our\nimproved spectral resolution reveals more detailed features, especially in the\nmid and near-infrared.\n