E. N. Kopatskaya
A5052573477- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Neutrino Physics Research
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Stellar, planetary, and galactic studies
- Gyrotron and Vacuum Electronics Research
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Calibration and Measurement Techniques
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Particle accelerators and beam dynamics
- solar cell performance optimization
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
St Petersburg University
2015-2024
Turku Centre for Computer Science
2023
University of Turku
2023
Institute of Applied Astronomy
2010-2022
University of Rijeka
2021
We present results from monitoring the multi-waveband flux, linear polarization, and parsec-scale structure of quasar PKS 1510-089, concentrating on eight major gamma-ray flares that occurred during interval 2009.0-2009.5. The peaks were essentially simultaneous with maxima at optical wavelengths, although flux ratio two wavebands varied by an order magnitude. polarization vector rotated 720 degrees a 5-day period encompassing six these flares. This culminated in very bright, roughly 1 day,...
Abstract Most of the light from blazars, active galactic nuclei with jets magnetized plasma that point nearly along line sight, is produced by high-energy particles, up to around 1 TeV. Although are known be ultimately powered a supermassive black hole, how particles accelerated such high energies has been an unanswered question. The process must related magnetic field, which can probed observations polarization jets. Measurements radio optical polarization—the only range available until...
We analyze the behavior of parsec-scale jet quasar 3C 454.3 during pronounced flaring in 2005–2008. Three major disturbances propagated down along different trajectories with Lorentz factors Γ > 10. The show a clear connection millimeter-wave outbursts, 2005 May/June, 2007 July, and December. High-amplitude optical events R-band light curve precede peaks outbursts by 15–50 days. Each outburst is accompanied an increase X-ray activity. associate propagation superluminal knots derive location...
We present time-resolved broad-band observations of the quasar 3C 279 obtained from multi-wavelength campaigns conducted during first two years Fermi Gamma-ray Space Telescope mission. While investigating previously reported gamma-ray/optical flare accompanied by a change in optical polarization, we found that emission appears delayed with respect to gamma-ray about 10 days. X-ray reveal pair `isolated' flares separated ~90 days, only weak counterparts. The spectral structure measured...
We analyze the multifrequency behavior of quasar 3C 454.3 during three prominent \gamma-ray outbursts: 2009 Autumn, 2010 Spring, and Autumn. The data reveal a repeating pattern, including triple flare structure, in properties each outburst, which implies similar mechanism(s) location for all events. multi-frequency indicates that lower frequency events are co-spatial with outbursts, although emission varies on shortest timescales. determine variability from UV to IR wavelengths an outburst...
We present the results of optical (R band) photometric and polarimetric monitoring Very Long Baseline Array (VLBA) imaging blazar S5 0716+714 along with Fermi gamma-ray data during a multi-waveband outburst in 2011 October. analyze total polarized intensity images obtained VLBA at 43 GHz after outburst. Monotonic rotation linear polarization vector rate >50 degrees per night coincided sharp maximum flux. At same time, within uncertainties, new superluminal knot appeared, an apparent speed...
Since the launch of Fermi satellite, BL Lacertae has been moderately active at gamma-rays and optical frequencies until May 2011, when source started a series strong flares. The exceptional sampling achieved by GLAST-AGILE Support Program (GASP) Whole Earth Blazar Telescope (WEBT) in collaboration with Steward Observatory allows us to perform detailed comparison daily gamma-ray observations Fermi. Discrete correlation analysis between emission reveals time lag 0 +- 1 d, which suggests...
The radio quasar 3C 454.3 underwent an exceptional optical outburst lasting more than 1 year and culminating in spring 2005. maximum brightness detected was R = 12.0, which represents the most luminous state thus far observed (M_B ~ -31.4). In order to follow emission behaviour of source detail, a large multiwavelength campaign organized by Whole Earth Blazar Telescope (WEBT). Continuous optical, near-IR monitoring performed several bands. ToO pointings Chandra INTEGRAL satellites provided...
Context. The quasar 3C 279 is among the most extreme blazars in terms of luminosity and variability flux at all wavebands. Its variations polarization are quite complex therefore require intensive monitoring observations multiple wavebands to characterise interpret observed changes.
Aims. Since the CGRO operation in 1991–2000, one of primary unresolved questions about blazar γ-ray emission has been its possible correlation with low-energy (in particular optical) emission. To help answer this problem, Whole Earth Blazar Telescope (WEBT) consortium organized GLAST-AGILE Support Program (GASP) to provide optical-to-radio monitoring data be compared detections by AGILE and GLAST satellites. This new WEBT project started early September 2007, just before a strong detection...
Context. Over the past few years, on several occasions, large, continuous rotations of electric vector position angle (EVPA) linearly polarized optical emission from blazars have been reported. These events are often coincident with high energy γ-ray flares and they attracted considerable attention, since could allow us to probe magnetic field structure in emitting region jet. The flat-spectrum radio quasar 3C 279 is one most prominent examples showing this behaviour.
Abstract In an effort to locate the sites of emission at different frequencies and physical processes causing variability in blazar jets, we have obtained high time-resolution observations BL Lacertae over a wide wavelength range: with Transiting Exoplanet Survey Satellite (TESS) 6000–10000 Å 2 minute cadence; Neil Gehrels Swift satellite optical, UV, X-ray bands; Nuclear Spectroscopic Telescope Array hard Fermi Large Area γ -ray energies; Whole Earth Blazar for measurement optical flux...
Aims. The Whole Earth Blazar Telescope (WEBT) consortium has been monitoring the blazar 3C 454.3 from radio to optical bands since 2004 study its emission variability properties.
The blazar 3C 454.3 underwent an unprecedented optical outburst in spring 2005. This was first followed by a mm and then cm radio outburst, which peaked February 2006. We report on follow-up observations the WEBT to study multiwavelength emission post-outburst phase. XMM-Newton July December 2006 added information X-ray UV fluxes. source faint state. flux at higher frequencies showed fast decreasing trend, represents tail of big outburst. It quiescent state, common all frequencies. In...
<i>Context. <i/>Since 2001, the radio quasar 3C 454.3 has undergone a period of high optical activity, culminating in brightest state ever observed, during 2004-2005 outburst. The Whole Earth Blazar Telescope (WEBT) consortium carried out several multifrequency campaigns to follow source behaviour.<i>Aims. <i/>The GLAST-AGILE Support Program (GASP) was born from WEBT provide long-term continuous optical-to-radio monitoring sample <i>γ<i/>-loud blazars, operation AGILE and GLAST (now known as...
Since 1997, BL Lacertae has undergone a phase of high optical activity, with the occurrence several prominent outbursts. Starting from 1999, Whole Earth Blazar Telescope (WEBT) consortium organized various multifrequency campaigns on this blazar, collecting tens thousands data points. One main issues in study huge dataset been search for correlations between and radio flux variations, possible periodicities light curves. The analysis assembled during first four (comprising also archival to...
We present multiwavelength observations of 3C 454.3 from April 2008 to March 2010. The radio optical data are mostly the GASP-WEBT, UV and X-ray Swift, gamma-ray AGILE Fermi satellites. improved calibration optical-UV UVOT OM instruments estimated Lyalpha flux disentangle contributions different components in this spectral region. reveal prominent variability above 8 GHz. In band, amplitude decreases with increasing frequency due a steadier radiation both broad line region an accretion disc....
We report on the extreme gamma-ray activity from FSRQ PKS 1510-089 observed by AGILE in March 2009. In same period a radio-to-optical monitoring of source was provided GASP-WEBT and REM. Moreover, several Swift ToO observations were triggered, adding important information behaviour optical/UV to hard X-rays. paid particular attention calibration Swift/UVOT data make it suitable blazars spectra. Simultaneous radio gamma rays allowed us study detail correlation among emission variability at...
We present the results of a comparison between classical and newly identified EXor based on literature data aimed at recognizing possible differences or similarities categories. Optical near-IR two-color diagrams, modalities fluctuations, derived values mass accretion rates are indicative strong two samples. demonstrate how difference outburst quiescence spectral energy distribution all can be well fitted with single blackbody, as if an additional thermal component appears during outbursting...
The quasar-type blazar 4C 38.41 (B3 1633+382) experienced a large outburst in 2011, which was detected throughout the entire electromagnetic spectrum. We present results of low-energy multifrequency monitoring by GASP project WEBT consortium and collaborators, as well those spectropolarimetric/spectrophotometric at Steward Observatory. also analyse high-energy observations Swift Fermi satellites. In optical-UV band, several indicate that there is contribution from QSO-like emission...
We perform a multi-wavelength polarimetric study of the quasar CTA 102 during an extraordinarily bright γ-ray outburst detected by Fermi Large Area Telescope in 2012 September–October when source reached flux F>100 MeV = 5.2 ± 0.4 × 10−6 photons cm−2 s−1. At same time, displayed unprecedented optical and near-infrared (near-IR) outburst. evolution parsec-scale jet with ultra-high angular resolution through sequence 80 total polarized intensity Very Long Baseline Array images at 43 GHz,...