منابع مشابه
Are the X-ray spectra of flat-spectrum radio quasars and BL Lacertae objects different?
We study the X-ray spectra of 114 flat-spectrum radio quasars (FSRQ) using the hardness ratios as given in the WGA catalogue of ROSAT sources. This sample includes all WGA FSRQ with high-quality data and comprises about 20 per cent of presently known such objects, which makes this the largest FSRQ sample ever studied in the X-ray band. We find that FSRQ have a distribution of energy spectral in...
متن کاملMultiwaveband Observations of Quasars with Flat Radio Spectra and Strong Millimeter-wave Emission
We present multiwaveband observations of a well-selected sample of 28 quasars and two radio galaxies with Ñat radio spectra and strong millimeter-wave emission (referred to here as FSRQs). The data are analyzed to determine the radio to infrared and X-ray to c-ray properties of FSRQs and the relationships between them. SpeciÐcally, the synchrotron self-Compton (SSC) process is examined as a lik...
متن کاملThe host galaxies of flat-spectrum quasars
We present the results of deep VLT-ISAAC Ks-band imaging of four z ∼ 1.5 flatspectrum quasars selected from the Parkes half-Jansky flat spectrum sample. We find that the hosts of these flat-spectrum quasars are consistent with lying on the K−z Hubble relation for radio galaxies. This implies that the flat-spectrum quasar hosts fall in line with the expectations from orientation based unified sc...
متن کاملComputation of the Spectra of the Quasars
The repartition of redshifts of the lines observed in the spectra of the quasars is generally considered as stochastic, but several authors showed that the difference of two redshifts is the product of an integer by a basic redshift z f = 0.062. This property results from a coherent Raman effect during the propagation of the incoherent light in a halo of atomic hydrogen , without any jet of gas...
متن کاملHigh resolution X-ray spectra of quasars
Past X-ray observations by ASCA suggest that warm absorbers (Ovii and Oviii edges) are apparently rare in high luminosity AGNs (quasars) while they are more common in low luminosity AGNs (Seyferts). However, this could be a selection effect if high luminosity AGNs have mostly narrow absorption lines (with no strong bound free edges), which escaped detection by the low resolution of ASCA. To che...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1973
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/161.1.31p