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相关论文: The CLASS blazar survey: testing the blazar sequen…

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The overall spectra (SED) of blazars, from radio to gamma-ray energies, seem to obey well defined trends, with a continuity of properties between blazars of different classes. To quantify this statement we can either investigate their…

天体物理学 · 物理学 2007-05-23 Gabriele Ghisellini

We have carried out a multifrequency analysis of the radio variability of blazars, exploiting the data obtained during the extensive monitoring programs carried out at the University of Michigan Radio Astronomy Observatory (UMRAO, at 4.8,…

To fully exploit the scientific potential of the Fermi mission, we initiated the F-GAMMA program. Between 2007 and 2015 it was the prime provider of complementary multi-frequency monitoring in the radio regime. We quantify the radio…

To investigate the poorly constrained sub-mm counts and spectral properties of blazars we searched for these in the Herschel-ATLAS (H-ATLAS) science demostration phase (SDP) survey catalog. We cross-matched 500$\mu$m sources brighter than…

We revisit the blazar sequence exploiting the complete, flux limited sample of blazars with known redshift detected by the Fermi satellite after 4 years of operations (the 3LAC sample). We divide the sources into gamma-ray luminosity bins,…

高能天体物理现象 · 物理学 2017-05-31 G. Ghisellini , C. Righi , L. Costamante , F. Tavecchio

The gamma-ray energy spectra of bright blazars of the LAT Bright AGN Sample (LBAS) are investigated using Fermi-LAT data. Spectral properties (hardness, curvature and variability) established using a data set accumulated over 6 months of…

高能天体物理现象 · 物理学 2015-05-18 LAT Collaboration

Blazars are the established sources of an intense and variable non-thermal radiation extending from radio wavelengths up to HE and VHE gamma-rays. Understanding the spectral evolution of blazars in selected frequency ranges, as well as…

高能天体物理现象 · 物理学 2014-12-24 Alicja Wierzcholska , Michał Ostrowski , Łukasz Stawarz , Stefan Wagner , Marcus Hauser

We present a first systematic time series study of a sample of blazars observed by the Transiting Exoplanet Survey Satellite $\textit{TESS}$ spacecraft. By cross matching the positions of the sources in the TESS observations with those from…

高能天体物理现象 · 物理学 2022-11-23 Vivek Reddy Pininti , Gopal Bhatta , Sagarika Paul , Aman Kumar , Aayushi Rajgor , Rahul Barnwal , Sarvesh Gharat

We present a method to assess the reliability of the identification of EGRET sources with extragalactic radio sources. We verify that EGRET is detecting the blazar class of AGN. However, many published identifications are found to be…

天体物理学 · 物理学 2009-10-28 J. R. Mattox , J. Schachter , L. Molnar , R. C. Hartman , A. R. Patnaik

We present statistical analyses of a large homogenous data sample of Fermi-detected blazars thoroughly studied in order to reassess the relationship between flat-spectrum radio quasars (FSRQs) and subclasses of BL Lacertae objects (BL Lacs)…

高能天体物理现象 · 物理学 2021-08-18 E. U. Iyida , F. C. Odo , A. E. Chukwude , A. A. Ubachukwu

To study a statistical properties of different classes of radio sources, we defined and observed the Bologna Complete Sample (BCS) which is unbiased with respect to the orientation of the nuclear relativistic jet being selected from…

高能天体物理现象 · 物理学 2011-10-31 E. Liuzzo , G. Giovannini , M. Giroletti

Using Chandra imaging spectroscopy and VLA L-band maps, we have identified radio galaxies at P(1.4 GHz) >= 3x10^{23} W Hz^{-1} and X-ray point sources (XPSs) at L(0.3-8 keV) >= 10^{42} ergs s^{-1} in 11 moderate redshift (0.2<z<0.4)…

宇宙学与河外天体物理 · 物理学 2009-10-16 Quyen N. Hart , John T. Stocke , Eric J. Hallman

According to a generally accepted paradigm, small intrinsic sizes of Compact Steep Spectrum (CSS) radio sources are a direct consequence of their youth, but in later stages of their evolution they are believed to become large-scale sources.…

天体物理学 · 物理学 2009-11-13 Andrzej Marecki , Magdalena Kunert-Bajraszewska , Ralph E. Spencer

Observations at millimetre wavelengths are presented for a representative sample of 22 X-ray-selected BL Lac objects (XBLs). This sample comprises 19 High-energy cutoff BL Lacs objects (HBLs), 1 Low-energy cutoff BL Lac object (LBL) and 2…

天体物理学 · 物理学 2009-10-31 J. A. Stevens , W. K. Gear

The Very Large Array Sky Survey (VLASS) is observing the entire sky north of $-40^{\circ}$ in the S-band ($2<\nu<4\,$GHz), with the highest angular resolution ($2''.5$) of any all-sky radio continuum survey to date. VLASS will cover its…

In this paper we present the results of a 4-year (1996 - 1999) radio flux density monitoring program for a sample of X- and $\gamma$-ray loud blazars. Our program started in January 1996 and was carried out on monthly basis at the…

The X-ray spectrum of extreme HBL type blazars is located in the synchrotron branch of the broadband spectral energy distribution (SED), at energies below the peak. A joint fit of the extrapolated X-ray spectra together with a host galaxy…

高能天体物理现象 · 物理学 2020-06-10 Alicja Wierzcholska , Stefan Wagner

The parsec-scale radio properties of 232 active galactic nuclei (AGNs), most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long…

高能天体物理现象 · 物理学 2015-06-11 J. D. Linford , G. B. Taylor , F. K. Schinzel

We describe the selection of candidate radio-loud quasars obtained by cross-matching radio source positions from the low-frequency (151 MHz) 7C survey with optical positions from five pairs of EO POSS-I plates scanned with the Cambridge…

We present the results of our analysis devoted to the research of sources emitting in the energy bands surveyed by both the Swift-BAT and the Fermi-LAT telescopes. We cross-correlate the Fermi-LAT 1-year point source catalogue (1FGL) of…

高能天体物理现象 · 物理学 2015-05-27 A. Maselli , G. Cusumano , E. Massaro , A. Segreto , V. La Parola , A. Tramacere , I. Donnarumma
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