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Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/44701
Title: Suzaku Observatio1 ns of Luminous Quasars: 2 Revealing the Nature of High-Energy Blazar Emission 3 in Low-level activity States
Other Titles: Suzaku Observations of Luminous Quasars: Revealing the Nature of High-Energy Blazar Emission in Quiescent States
Authors: Abdo, Aous A.; Caliandro, Giuseppe Andrea ; Rodríguez, Ana Yaiza; Sato, Rie; Torres, Diego F.
Keywords: Galaxies: active
Galaxies: jets
Radiation mechanisms: non-thermal
X-rays: galaxies
Issue Date: 21-May-2010
Publisher: American Astronomical Society
Institute of Physics Publishing
Citation: Astrophysical Journal 716 (1) : 835 (2010)
Abstract: We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS 0208–512, Q 0827+243, PKS 1127–145, PKS 1510–089, and 3C 454.3. All these sources were additionally monitored simultaneously or quasi-simultaneously by the Fermi satellite in gamma rays and the Swift UVOT in the UV and optical bands, respectively. We constructed their broadband spectra covering the frequency range from 1014 Hz up to 1025 Hz, and those reveal the nature of high-energy emission of luminous blazars in their low-activity states. The analyzed X-ray spectra are well fitted by a power-law model with photoelectric absorption. In the case of PKS 0208–512, PKS 1127–145, and 3C 454.3, the X-ray continuum showed indication of hardening at low energies. Moreover, when compared with the previous X-ray observations, we see a significantly increasing contribution of low-energy photons to the total X-ray fluxes when the sources are getting fainter. The same behavior can be noted in the Suzaku data alone. A likely explanation involves a variable, flat-spectrum component produced via inverse-Compton emission, plus an additional, possibly steady soft X-ray component prominent when the source gets fainter. This soft X-ray excess is represented either by a steep power-law (photon indices Γ ~ 3-5) or a blackbody-type emission with temperatures kT ~ 0.1-0.2 keV. We model the broadband spectra of the five observed FSRQs using synchrotron self-Compton and/or external-Compton radiation models. Our modeling suggests that the difference between the low- and high-activity states in luminous blazars is due to the different total kinetic power of the jet, most likely related to varying bulk Lorentz factor of the outflow within the blazar emission zone.
Description: El PDF auto-archivado en Digital.CSIC es el PRE-PRINT del autor.-- arXiv:1004.2857. -- 36 páginas, 8 figuras, 11 tablas. -- Autores: Abdo, Aous A. ... [et al.]
Publisher version (URL): http://dx.doi.org/10.1088/0004-637X/716/1/835
URI: http://hdl.handle.net/10261/44701
DOI: 10.1088/0004-637X/716/1/835
ISSN: 0004-637X
E-ISSN: 1538-4357
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