Related papers: Mid-infrared Variability of gamma-ray emitting bla…

We present multi-frequency scatter broadening evolution of 29 pulsars observed with the LOw Frequency ARray (LOFAR) and Long Wavelength Array (LWA). We conducted new observations using LOFAR Low Band Antennae (LBA) as well as utilized the…

We analyse a group of radio sources, a subset of the 200 mJy sample, all of which have core-jet radio structures measured with VLBI and have flat spectra stretching from the radio to the millimetre/sub-millimetre band. Thus the objects have…

High-redshift blazars are one of the most powerful monsters in the universe and $\gamma$-ray variability carries crucial information of their relativistic jets. In this work we present results of the first systematical temporal analysis of…

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…

We conducted a detailed long-term spectral and temporal study of flat spectrum radio quasar 4C +01.02, by using the multi-wavelength observations from Fermi-LAT, Swift-XRT, and Swift-UVOT. The $2$-day bin $\gamma$-ray lightcurve in the…

Flat-spectrum radio quasars (FSRQs) whose brightness is dominated by a relativistically beamed core, are frequently found in 'blazar state' commonly inferred from a high optical polarization ( > 3%), and/or a large continuum variability.…

We observed the prototype blazar, BL Lacertae, extensively in optical and radio bands during an active phase in the period 2010--2013 when the source showed several prominent outbursts. We searched for possible correlations and time lags…

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…

We study the correlation between the gamma-ray flux F_g, averaged over the first 11 months of Fermi survey and integrated above 100 MeV, and the radio flux density (F_r at 20 GHz) of Fermi sources associated with a radio counterpart in the…

Active galactic nuclei (AGNs) can power relativistic jets, which are called blazars when pointed close to our line of sight. Depending on the presence or absence of emission lines in their optical spectra, blazars are categorized into flat…

Densely time sampled multi-frequency flux measurements of the extreme BL Lac object S5 0716+714 over the past three years allow us to study its broad-band variability, and the detailed underlying physics, with emphasis on the location and…

We present the redshift evolutions and distributions of the gamma-ray luminosity and photon spectral index of flat spectrum radio quasar (FSRQ) type blazars, using non-parametric methods to obtain the evolutions and distributions directly…

Context: Being dominated by non-thermal emission from aligned relativistic jets, blazars allow us to elucidate the physics of extragalactic jets, and, ltimately, how the energy is extracted from the central black hole in radio-loud active…

We present results of a multi-epoch intra-night optical monitoring of eleven blazars consisting of six BL Lac objects and five radio core-dominated quasars (CDQs). These densely sampled and sensitive R-band CCD observations, carried out…

The Decadal IRAC Bootes Survey is a mid-IR variability survey of the ~9 sq. deg. of the NDWFS Bootes Field and extends the time baseline of its predecessor, the Spitzer Deep, Wide-Field Survey (SDWFS), from 4 to 10 years. The Spitzer Space…

We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS0208-512, Q0827+243, PKS1127-145, PKS1510-089 and 3C 454.3. All these sources were additionally monitored simultaneously or…

We carried out a pilot campaign of radio and optical band intra-day variability (IDV) observations of five blazars (3C66A, S5 0716+714, OJ287, B0925+504, and BL Lacertae) on December 18--21, 2015 by using the radio telescope in Effelsberg…

S5 0716+714 is a typical BL Lacertae object. In this paper we present the analysis and results of long term simultaneous observations in the radio, near-infrared, optical, X-ray and $\gamma$-ray bands, together with our own photometric…

We present simultaneous optical and X-ray data from Swift for a sample of FSRQs selected from the EMSS survey. We present also a complete analysis of Swift and INTEGRAL data on 4 blazars recently discussed as possibly challenging the trends…

Blazars are known for their energetic multiwavelength flares from radio wavelengths to high-energy $\gamma$-rays. In this work, we study radio, optical, and $\gamma$-ray light curves of 145 bright blazars spanning up to 8~yr, to probe the…