The New Generation Atlas of Quasar Spectral Energy Distributions from Radio to X-rays

TL;DR

This paper presents an updated, high-resolution atlas of quasar spectral energy distributions across the electromagnetic spectrum, based on high-quality, multi-wavelength data from various telescopes, improving upon previous work.

Contribution

It provides a comprehensive, high-resolution atlas of 85 quasars' SEDs, incorporating new data and detailed infrared features, updating and expanding the classic Elvis et al. (1994) study.

Findings

Similar overall SED shapes to Elvis et al. (1994)

Enhanced spectral detail in mid and near-infrared regions

Constructed composite SEDs for radio-loud and radio-quiet quasars

Abstract

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