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相关论文: BeppoSAX Observations of 1 Jy BL Lacertae Objects.…

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We report on the detection of excess hard X-ray emission from the TeV BL Lac object Mrk421 during the historical low-flux state of the source in January 2013. NuSTAR observations were conducted four times between MJD56294 and MJD56312 with…

高能天体物理现象 · 物理学 2016-08-17 Jun Kataoka , Lukasz Stawarz

We report on 16 BL Lacertae objects that were proposed to be at z > 1. We present spectroscopic observations secured at the 10.4m GTC that allowed us to assess the redshift of these sources. In particular, for five objects we disprove the…

高能天体物理现象 · 物理学 2018-07-25 M. Landoni , S. Paiano , R. Falomo , R. Scarpa , A. Treves

We present the analysis of archival data from ROSAT and ASCA of a serendipitous BL Lac object PKS 2316-423. Because of its featureless non-thermal radio/optical continuum, PKS 2316-423 has been called as a BL Lac candidate in the…

天体物理学 · 物理学 2009-10-31 Sui-Jian Xue , You-Hong Zhang , Jian-Sheng Chen

We study the quasi-simultaneous Spectral Energy Distributions (SED) of 48 LBAS blazars, collected within three months of the Fermi LAT Bright AGN Sample (LBAS) data taking period, combining Fermi and Swift data with radio NIR-Optical and…

高能天体物理现象 · 物理学 2009-12-21 S. Raino' , E. Cavazzuti , S. Colafrancesco , P. Giommi , A. Tramacere , the Fermi-LAT Collaboration

We present results from observations of 29 BL Lacertae objects, taken with the Whipple Observatory 10 m Gamma-Ray Telescope between 1995 and 2000. The observed objects are mostly at low redshift (z < 0.2) but observations of objects of z up…

天体物理学 · 物理学 2019-08-14 D. Horan

PKS 2155-304 is one of the prototypes of BL Lac objects. Its spectral energy distribution is known from the radio to the TeV band and has two peaks, one in the soft X-rays and the other in the TeV region. These may be interpreted within the…

We have organized an extensive multiwavelength campaign on BL Lacertae in the second half of 2000. Simultaneous or quasi-simultaneous observations were taken at radio frequencies, in the optical - carried out by the WEBT collaboration -, in…

The possibility to detect simultaneously in the X-ray band the synchrotron and Inverse Compton (IC)emission of intermediate BL Lac objects offers the unique opportunity to study contemporaneously the low- and high-energy tails of the…

天体物理学 · 物理学 2009-11-11 E. Ferrero , S. J. Wagner , D. Emmanoulopoulos , L. Ostorero

We have obtained spectral and timing data on GX 3+1 and Ser X-1. Both sources were observed simultaneously with BeppoSAX and RXTE. The RXTE data is used to provide power spectra and colour-colour diagrams in order to constrain the state…

天体物理学 · 物理学 2009-10-31 T. Oosterbroek , D. Barret , M. Guainazzi , E. C. Ford

Results obtained with BeppoSAX observations of blazars within various collaborative programs are presented. The spectral similarity "paradigm", whereby the spectral energy distributions of blazars follow a sequence, leading to a unified…

天体物理学 · 物理学 2009-10-31 L. Maraschi , L. Chiappetti , G. Fossati , E. Pian , F. Tavecchio

We present a new sample of 30 nearby (z<0.2) BL Lacs, selected to study the nuclear as well as the large scale properties of low power radio sources. In this first paper, we show and discuss new radio data taken with the VLA (19 objects at…

天体物理学 · 物理学 2009-11-10 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

1ES 1959+650 is one of the most remarkable high-peaked BL Lacertae objects (HBL). In 2002, it exhibited a TeV gamma-ray flare without a similar brightening of the synchrotron component at lower energies. We present the results of a…

高能天体物理现象 · 物理学 2010-10-19 E. Bottacini , M. Böttcher , P. Schady , A. Rau , X. -L. Zhang , M. Ajello , C. Fendt , J. Greiner

We report on the BeppoSAX observations of the gamma-ray blazar PKS 0528+134 performed in Feb and Mar 1997, during a multiwavelength campaign involving EGRET and ground based telescopes. The source was in a faint and hard state, with energy…

Aims: We present optical spectroscopy of a sample of BL Lac objects, to determine their redshift, to study their broad emission line properties and to characterize their close environment. Methods: Twelve objects were observed using the ESO…

天体物理学 · 物理学 2009-11-11 B. Sbarufatti , R. Falomo , A. Treves , J. Kotilainen , .

The spectral energy distribution of blazars around the synchrotron peak can be well described by the log-parabolic model that has three parameters: peak energy ($E_\textrm{p}$), peak luminosity ($L_\textrm{p}$) and the curvature parameter…

星系天体物理 · 物理学 2019-11-06 Yijun Wang , Shifu Zhu , Yongquan Xue , Minfeng Gu , Shanshan Weng , Huynh Anh N. Le

In this paper we investigate the properties of a sample of six BL Lacs by fitting their spectra using our inhomogeneous jet model with an accelerating, magnetically dominated, parabolic base, which transitions to a slowly decelerating…

高能天体物理现象 · 物理学 2015-06-17 William J. Potter , Garret Cotter

We report on the 0.5--200 keV spectral properties of Cyg X-1 observed at different epochs with the Narrow Field Instruments of the BeppoSAX satellite. The source was in its soft state during the first observation of 1996 June. In the second…

A BeppoSAX observation of the z=2.34 quasar PKS2149-306 produced a strong signal in the high energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The Beppo-SAX spectrum spans almost 3 decades…

The multi-frequency Sedentary Survey is a flux limited, statistically well-defined sample of highly X-ray dominated BL Lacertae objects (HBLs) which includes 150 sources. In this paper, the third of the series, we report the results of a…

天体物理学 · 物理学 2009-11-13 S. Piranomonte , M. Perri , P. Giommi , H. Landt , P. Padovani

The recent Cherenkov telescope observations and detections of the BL Lac objects Mkn 421, Mkn 501, 1ES 2344+514, PKS 2155--304 and possibly 1ES 1959+658 have shown that there exists a subclass of BL Lac objects emitting a substantial…

天体物理学 · 物理学 2009-10-31 Gabriele Ghisellini