Related papers: Correlated variability in the blazar 3C 454.3
We present the light curve data of a remarkable blazer 3C 454.3 (z=0.859) in optical, X-ray, and gamma-ray bands. Since January 2008, we have been monitoring this object using the 50 cm MITSuME, a optical telescope, and detected several…
We present multiwavelength observations of 3C 454.3 from April 2008 to March 2010. The radio to optical data are mostly from the GASP-WEBT, UV and X-ray data from Swift, and gamma-ray data from the AGILE and Fermi satellites. We improved…
We present a multi-wavelength temporal analysis of the blazar 3C 454.3 during the high $\gamma$-ray active period from May-December, 2014. Except for X-rays, the period is well sampled at near-infrared (NIR)-optical by the \emph{SMARTS}…
We present the results of a series of Swift and quasi simultaneous ground-based infra-red observations of the blazar 3C 454.3 carried out in April-May 2005 when the source was 10 to 30 times brighter than previously observed. We found 3C…
3C 454.3 is the most variable and intense extragalactic gamma-ray blazar detected by AGILE and Fermi during the last 4 years. This remarkable source shows extreme flux variability (about a fact or of 20) on a time-scale of 24-48 hours, as…
Blazars show optical and $\gamma$-ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based on an analysis of quasi-simultaneous data at optical,…
We present the time variability properties of a sample of six blazars, AO 0235+164, 3C 273, 3C 279, PKS 1510-089, PKS 2155-304, and 3C 454.3, at optical-IR as well as gamma-ray energies. These observations were carried out as a part of the…
We report the results of photometric observations of the blazars Mrk 421 and 3C 454.3 designed to search for intraday variability (IDV) and short-term variability (STV). Optical photometric observations were spread over eighteen nights for…
This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7 -…
We examine the long term (~10 years) gamma-ray variability of blazars observed by EGRET and Fermi and find that for six sources the average flux varied by more than an order of magnitude. For two of these sources (PKS 0208-512 and PKS…
In the early days of April 2010, the blazar 3C 454.3 (z=0.859) underwent a strong gamma-ray outburst, reaching fluxes (E > 100 MeV) in excess of 10^-5 ph cm^-2 s^-1. The Fermi Gamma ray Space Telescope performed a 200 ks long pointed…
The flat spectrum radio quasar 3C~454.3 underwent an extraordinary outburst in December 2009 when it became the brightest gamma-ray source in the sky for over one week. Its daily flux measured with the Fermi Large Area Telescope at photon…
Violent multi-wavelength variabilities are observed in gamma-ray-selected blazars. We present an analysis of long-term light curves for eight bright blazars to explore the co-variation pattern in the gamma-ray and radio bands. We extract…
We report on OVRO, WISE, Swift and Fermi-LAT observations of the high redshift blazar CGRaBS J0733+0456, from which significant flux variations in radio, infrared (IR) as well as $\gamma$-ray domains are detected. Particularly, the…
Recent detection of suborbital gamma-ray variability of Flat Spectrum Radio Quasar (FSRQ) 3C 279 by Fermi Large Area Telescope (LAT) is in severe conflict with established models of blazar emission. This paper presents the results of…
Due to its peculiar and highly variable nature, the blazar 3C 454.3 has been extensively monitored by the WEBT team. Here, we present for the first time these long-term optical flux and color variability results using data acquired in B, V,…
The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra…
We present and analyse the WEBT multifrequency observations of 3C 454.3 in the 2007-2008 observing season, including XMM-Newton observations and near-IR spectroscopic monitoring, and compare the recent emission behaviour with the past one.…
The gamma-ray blazar 3C 279 was monitored on a nearly daily basis with IUE, ROSAT and EGRET for three weeks between December 1992 and January 1993. During this period, the blazar was at a historical minimum at all wavelengths. Here we…
We report on multiwavelength observations of the blazar PKS 0537-441 (z = 0.896) obtained from microwaves through gamma rays by SMA, REM, ATOM, Swift and Fermi during 2008 August-2010 April. Strong variability has been observed in gamma…