2003/02/13 by J. K. Gambill, R. M. Sambruna, G. Chartas +6
Physics and Astronomy · #Active galactic nucleus #Amplitude #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #OVV quasar #Observatory #Optics #Physics #Quasar #Radio galaxy #Redshift #Spectral index #Spectral line #astro-ph
paper · pdf · doi:10.1051/0004-6361:20030173
published as Astron.Astrophys. 401 (2003) 505-518 · 14 pages, 5 figures, Accepted for publication in Astronomy & Astrophysics
arxiv created 2003/02/13 · openalex publication_date 2003/03/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range –1.96, and one low-power radio-galaxy at . No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of ~25 min. The X-ray spectra of the quasar cores are generally well described by a single power law model with Galactic absorption. However, in six quasars we find soft X-ray excess emission below 1.6 keV. Interestingly, we detect an Fe K-shell emission line, consistent with fluorescent Kα emission from cold iron, in one lobe- and two core-dominated sources. The average X-ray photon index for the quasars in the sample is and dispersion . The average spectral slope for our sample is flatter than the slope found for radio-quiet quasars and for radio-loud AGNs with larger jet orientations; this indicates that beaming affects the X-ray emission from the cores in our sample of quasars.