V. M. Larionov
A5032540620- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Gyrotron and Vacuum Electronics Research
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Calibration and Measurement Techniques
- Radiation Detection and Scintillator Technologies
- Ionosphere and magnetosphere dynamics
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Atmospheric Ozone and Climate
- Scientific Measurement and Uncertainty Evaluation
- SAS software applications and methods
St Petersburg University
2014-2024
Institute of Applied Astronomy
2012-2023
Pulkovo Observatory
2014-2023
Petersburg Nuclear Physics Institute
2020-2021
University of Rijeka
2021
Boston University
2017
Center for Astrophysics Harvard & Smithsonian
2017
Aalto University
2015-2016
Isaac Newton Institute
2007-2016
Isaac Newton Institute for Mathematical Sciences
2010-2015
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,...
We present the results of one-year long observational campaign type II plateau SN 2005cs, which exploded in nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes 2005cs best observed low-luminosity, 56Ni-poor event so far and one core-collapse supernovae ever. The optical near-infrared spectra show narrow P-Cygni lines characteristic this family, are indicative a very low expansion velocity (about 1000 km s−1) ejected material. light curves cover both phase late-time...
We combine time-dependent multi-waveband flux and linear polarization observations with sub-milliarcsecond-scale polarimetric images at lambda=7mm of the BL Lacertae-type blazar OJ287 to locate gamma-ray emission in prominent flares jet source >14pc from central engine. demonstrate a highly significant correlation between strongest millimeter-wave through Monte-Carlo simulations. The two reported peaks occurred near beginning major mm-wave outbursts, each which is associated maximum...
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 extensive multi-waveband monitoring blazar 3C~279 between 1996 and 2007 at X-ray energies (2-10 keV), optical R band, 14.5 GHz, as well imaging with Very Long Baseline Array (VLBA) 43 GHz. In all bands power spectral density corresponds to "red noise" that can be fit by a single law over sampled time scales. Variations in flux three wavebands are significantly correlated. The delay high low frequency changes substantially on scales years. A major multi-frequency...
We present new optical and near infrared (NIR) photometry spectroscopy of the type IIP supernova, SN 2004et. In combination with already published data, this provides one most complete studies NIR data for any from just after explosion to +500 days. The contribution flux bolometric light curve is estimated increase 15% at around 50% end plateau then declines 40% 300 2004et luminous SNe which has been well studied, a luminosity log L = 42.3 erg/s, it 2 times brighter than 1999em. provide...
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...
We present observations of a major outburst at centimeter, millimeter, optical, X-ray, and γ-ray wavelengths the BL Lacertae object AO 0235+164. analyze timing multi-waveband variations in flux linear polarization, as well changes Very Long Baseline Array images λ = 7 mm with ∼0.15 milliarcsec resolution. The association events different wavebands is confirmed high statistical significance by probability arguments Monte Carlo simulations. A series sharp peaks optical pronounced maximum...
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...
We present UBVRI light curves of BL Lacertae from May 2000 to January 2001, obtained by 24 telescopes in 11 countries. More than 15000 observations were performed that period, which was the extension Whole Earth Blazar Telescope (WEBT) campaign originally planned for July-August 2000. Rapid flux oscillations are all time, involving variations up a few tenths mag on hour time scales, and witnessing an intense intraday activity this source. Colour indexes have been derived coupling highest...
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...
BL Lacertae has been the target of four observing campaigns by Whole Earth Blazar Telescope (WEBT) collaboration. In this paper we present $UBVRI$ light curves obtained WEBT from 1994 to 2002, including last, extended Lac 2001 campaign. A total about 7500 optical observations performed 31 telescopes Japan Mexico have collected, be added $\sim 15600$ Campaign 2000. All these data allow one follow source emission behaviour with unprecedented detail. The analysis colour indices reveals that...
We present photometric and spectroscopic observations at optical near-infrared wavelengths of the nearby type Ic SN 2007gr. These represent most extensive data-set to date any supernova this sub-type, with frequent coverage from shortly after discovery more than one year post-explosion. deduce a rise time B-band maximum 11.5 \pm 2.7 days. find peak magnitude M_B=-16.8, light curves which are remarkably similar so-called 'hypernova' 2002ap. In contrast, spectra SNe 2007gr 2002ap show marked...
We report the first results of a long term infrared monitoring campaign known and candidate galactic Luminous Blue Variables (LBVs). In particular, we are able to confirm LBV nature G24.73+0.69, luminous mid-B supergiant associated with dusty ejection nebula. find that prior 2003 September G24.73+0.69 exhibited low amplitude ( mag) variability, but in ~200 day period between September–2004 April it abruptly brightened by ~0.7 mag broadband J filter. Subsequently, further ~0.4 increase was...
We present optical and infrared observations of the unusual Type Ia supernova (SN) 2004eo. The light curves spectra closely resemble those prototypical SN 1992A, luminosity at maximum (M_B = -19.08) is close to average for a Ia. However, ejected 56Ni mass derived by modelling bolometric curve (about 0.45 solar masses) lies near lower limit distribution observed in normal SNe Accordingly, 2004eo shows relatively rapid post-maximum decline (Delta m_(B) 1.46), small expansion velocities ejecta,...
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...
We present optical, X-ray, high energy ($\lessapprox 30$ GeV) and very ($\gtrapprox 100$ GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 June 23. A $\gamma$-ray signal was detected by AGILE with \sqrt{TS}=4.5 on 9--15, $F(E>100 \mathrm{MeV})= 42^{+14}_{-12}\times 10^{-8}$ photons cm$^{-2}$ s$^{-1}$. This flaring state is brighter than average flux observed EGRET a factor $\sim$3, but still consistent highest flux. In hard X-rays (20-60 keV)...
Since 2005, the blazar 3C 454.3 has shown remarkable flaring activity at all frequencies, and during last four years it exhibited more than one γ-ray flare per year, becoming most active in sky. We present for first time multi-wavelength AGILE, Swift, INTEGRAL, GASP-WEBT data collected order to explain extraordinary of which occurred 2010 November. On November 20 (MJD 55520), reached a peak flux (E >100 MeV) Fpγ = (6.8 ± 1.0) × 10−5 photons cm−2 s−1 on timescale about 12 hr, factor six...
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.