相关论文: Anomalous Entropic Behavior Observed in Quasar 3C …

Chandra X-ray observations of the high redshift (z =1.532) radio-loud quasar 3C270.1 in 2008 February show the nucleus to have a power-law spectrum, Gamma = 1.66 +/- 0.08, typical of a radio-loud quasar, and a marginally-detected Fe Kalpha…

We have measured mid-infrared radiation from an orientation-unbiased sample of 3CRR galaxies and quasars at redshifts 0.4 < z < 1.2 with the IRS and MIPS instruments on the Spitzer Space Telescope. Powerful emission (L_24micron > 10^22.4…

We study a curve of Gibbsian families of complex 3x3-matrices and point out new features, absent in commutative finite-dimensional algebras: a discontinuous maximum-entropy inference, a discontinuous entropy distance and non-exposed faces…

We have monitored the quasar 3C 273 in optical $V$, $R$ and $I$ bands from 2005 to 2016. Intraday variability (IDV) is detected on seven nights. The variability amplitudes for most of nights are less than 10\% and four nights more than…

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

We report the results of a 3-weeks multi-wavelength campaign on the flat spectrum radio quasar 3C 273 carried out with the AGILE gamma-ray mission, covering the 30 MeV -50 GeV and 18-60 keV, the REM observatory (covering the near-IR and…

We propose a different way to obtain the distribution of the luminosity function of quasars by using the Principle of Maximum Entropy. The input data comes from the SDSS-DR3 quasars counts, extending up to redshift 5 and limited from…

We report on the detection of a soft spatially-extended component of X-ray emission around four intermediate-redshift 3C quasars observed with Chandra: 3C254, 3C263, 3C275.1 and 3C281. The bolometric luminosity of this emission ranges over…

This study explores the interaction between non-extensive entropic FLRW cosmology and the power-law inflationary model, with a focus on the overlap between the scalar spectral index `$n_s$' and the tensor-to-scalar ratio `$r$'. Based on a…

Optical observations of a sample of 12 $\gamma$-ray bright blazars from four optical data archives, AAVSO, SMARTS, Catalina, and Steward Observatory, are compiled to create densely sampled light curves spanning more than a decade. As a part…

The blazar 3C 454.3 was revealed by the Fermi Gamma-ray Space Telescope to be in an exceptionally high flux state in July 2008. Accordingly, we performed a multi-wavelength monitoring campaign on this blazar using IR and optical…

The X-ray luminosity function of distant (3<z<5.1) unabsorbed quasars has been measured. A sample of distant high-luminosity quasars ($10^{45} \leq L_{{\rm X},2-10} < 7.5 \times 10^{45}$ erg/s in the 2--10 keV energy band) from the catalog…

We present a detailed temporal and spectral study of the blazar 3C\,279 using multi-wavelength observations from Swift-XRT, Swift-UVOT and Fermi-LAT during a flare in 2018 January. The temporal analysis of $\gamma$-ray light curve indicates…

We present the results of a three-week daily monitoring campaign on the quasar 3C 279 by the X-ray satellites RXTE and ROSAT. A cross correlation provides no evidence for any time lag between the very similar soft and hard X-ray light…

We report the results from an ASCA observation of the high-luminosity, radio-loud quasar PKS 0637-752 (redshift 0.654), covering the 0.8-15 keV band in the quasar-frame. We find the source to have a luminosity ~10^46 erg/s in the 2-10 keV…

We have undertaken a nearly simultaneous optical/UV and X-ray variability study of the flat spectrum radio quasar, 3C 273 using data available from the XMM$-$Newton satellite mission from June 2000 to July 2012. Here we focus on the…

Since its discovery in 1963, 3C273 has become one of the most widely studied quasars with investigations spanning the electromagnetic spectrum. While much has been discovered about this historically notable source, its low-frequency…

Context. 3C 454.3 is a very active flat spectrum radio quasar (blazar) that has undergone a recent outburst in all observed bands, including the optical. Aims. In this work we explore the short-term optical variability of 3C 454.3 during…

We present the results of a long-look monitoring of 3C273 with RXTE between 1996 and 2000. A total of 230 observations amounts to a net exposure of 845ksec, with this spectral and variability analysis of 3C273 covering the longest…

We report the results of quasi-simultaneous observations of the bright quasar 3C 273 using the BeppoSAX Low-Energy Concentrator Spectrometer (LECS) and the ASCA Solid-State Imaging Spectrometer (SIS). These observations are part of an…