A catalogue of optical to X-ray spectral energy distributions of z ≈ 2 quasars observed with Swift – I. First results
| Autor: | Marianne Vestergaard, S. I. Raimundo, D. Lawther, D. Grupe |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Swift 010308 nuclear & particles physics Astrophysics::High Energy Astrophysical Phenomena Foundation (engineering) FOS: Physical sciences Spectral density Astronomy and Astrophysics Quasar Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences 010303 astronomy & astrophysics computer Astrophysics::Galaxy Astrophysics Independent research computer.programming_language |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 467:4674-4710 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stx423 |
| Popis: | 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. Comment: 45 pages (of which, 18 pages main text). Accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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