A Chandra Snapshot Survey of Representative High-Redshift Radio-Loud Quasars from the Parkes-MIT-NRAO Sample

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dc.creatorLopez, L. A.
dc.creatorBrandt, W. N.
dc.creatorVignali, C.
dc.creatorSchneider, D. P.
dc.creatorChartas, G.
dc.creatorGarmire, G. P.
dc.date2006-01-02
dc.date.accessioned2026-07-07T11:25:08Z
dc.date.available2026-07-07T11:25:08Z
dc.descriptionWe present the results of Chandra ACIS-S snapshot observations of six radio-loud quasars (RLQs) at z=3.5-4.7. These observations sample luminous RLQs with moderate-to-high radio-loudness (R=200-9600) and aim to connect the X-ray properties of radio-quiet quasars (R<10) and highly radio-loud blazars (R>1000) at high redshift. This work extends a study by Bassett et al. (2004) which used similar methods to examine z > 4 RLQs with moderate radio-loudness (R=40-400). All of our targets are clearly detected. A search for extended X-ray emission associated with kpc-scale radio jets revealed only limited evidence for X-ray extension in our sample: three sources showed no evidence of X-ray extension, and the other three had 3-30% of their total X-ray fluxes extended >1 arcsec away from their X-ray cores. Additionally, we do not observe any systematic flattening of the optical-to-X-ray spectral index (alpha_{ox}) compared to low-redshift quasars. These results suggest that kpc-scale X-ray jet emission is not dominated by inverse-Compton scattering of CMB-seed photons off jet electrons. We measured X-ray continuum shapes and performed individual and joint spectral fits of our data combined with eight archival RLQs. A single power-law model acceptably fit the data. We added an intrinsic absorption component to our model, and neither the moderate-R nor the high-R fits set a lower bound on N_H. Our spectral results suggest that intrinsic absorption does not strongly depend on radio-loudness, and high-R sources have flatter power laws than moderate-R sources. Overall, our high-redshift RLQs have basic X-ray properties consistent with similar RLQs in the local universe.
dc.description24 pages, 5 figures, Accepted by AJ
dc.identifierhttps://arxiv.org/abs/astro-ph/0601037
dc.identifierhttp://arxiv.org/abs/astro-ph/0601037
dc.identifierAstron.J.131:1914-1922,2006
dc.identifierdoi:10.1086/500827
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/195418
dc.subjectAstrophysics
dc.titleA Chandra Snapshot Survey of Representative High-Redshift Radio-Loud Quasars from the Parkes-MIT-NRAO Sample
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