# A catalog of optical to X-ray spectral energy distributions of z~2 quasars observed with Swift. I: First results

## TL;DR

This study presents the optical to X-ray spectral energy distributions of 44 quasars at z~2 observed with Swift, highlighting differences between radio loud and quiet quasars and providing insights into their accretion properties.

## Contribution

First results from a program characterizing the SEDs of moderate-redshift quasars, focusing on radio loud objects and their X-ray brightness and spectral properties.

## Key findings

- Radio loud quasars are X-ray bright with hard spectra.
- Quasars exhibit high accretion luminosities between 0.7×10^46 and 5.2×10^47 erg/s.
- Eddington ratios indicate substantial accretion activity, between 0.1 and 1.

## Abstract

We present the Swift optical to X-ray spectral energy distributions (SEDs) of 44 quasars at redshifts z~2 observed by Swift, part of a larger program to establish and characterize the optical through X-ray SEDs of moderate-redshift quasars. Here we outline our analysis approach and present preliminary analysis and results for the first third of the full quasar sample. Not all quasars in the sample are detected in X-rays; all of the X-ray detected objects so far are radio loud. As expected for radio loud objects, they are X-ray bright relative to radio-quiet quasars of comparable optical luminosities, with an average alpha_ox = 1.39 +/- 0.03 (where alpha_ox is the power-law slope connecting the monochromatic flux at 2500 Ang and at 2 keV), and display hard X-ray spectra. We find integrated 3000 Ang - 25 keV accretion luminosities of between 0.7*10^(46) erg s^(-1) and 5.2*10^(47) erg s^(-1). Based on single-epoch spectroscopic virial black hole mass estimates, we find that these quasars are accreting at substantial Eddington fractions, 0.1 \le L/LEdd \le 1.