A5034183659- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Advanced X-ray Imaging Techniques
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- SAS software applications and methods
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- X-ray Spectroscopy and Fluorescence Analysis
- Geophysics and Gravity Measurements
- Advanced X-ray and CT Imaging
- Spacecraft Design and Technology
- Radio Astronomy Observations and Technology
- Particle Accelerators and Free-Electron Lasers
- CCD and CMOS Imaging Sensors
- Nuclear Physics and Applications
- Optical Systems and Laser Technology
- Calibration and Measurement Techniques
- Planetary Science and Exploration
Czech Academy of Sciences, Astronomical Institute
2014-2024
Czech Technical University in Prague
2015-2024
Kazan Federal University
2017-2024
Czech Academy of Sciences
2004-2023
Mars Space (United Kingdom)
2014-2019
University of Leicester
2017-2019
National Institute for Astrophysics
2010-2019
University of Ferrara
2019
University of Geneva
2019
Astronomical Observatory of Capodimonte
2018
The INTEGRAL Science Data Centre (ISDC) provides the data and means to analyse them scientific community. ISDC runs a gamma ray burst alert system that position of bursts on sky within seconds It operates quick-look analysis few hours detects new unexpected sources as well it monitors instruments. processes through standard results which are provided observers together with their data.
ABSTRACT OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in binary black hole model. The model predicted major outburst 2015 December. We found the did occur within expected time range, peaking on December 5 at magnitude 12.9 R -band. Based Swift /XRT satellite measurements and polarization data, we find it included thermal component. Its timing provides an accurate estimate for spin of primary hole, . present also...
eXTP is a science mission designed to study the state of matter under extreme conditions density, gravity and magnetism. Primary goals are determination equation at supra-nuclear measurement QED effects in highly magnetized star, accretion strong-field regime gravity. targets include isolated binary neutron stars, strong magnetic field systems like magnetars, stellar-mass supermassive black holes. The carries unique unprecedented suite state-of-the-art scientific instruments enabling for...
Abstract Results from regular monitoring of relativistic compact binaries like PSR 1913+16 are consistent with the dominant (quadrupole) order emission gravitational waves (GWs). We show that observations associated binary black hole (BBH) central engine blazar OJ 287 demand inclusion radiation reaction effects beyond quadrupolar order. It turns out even certain hereditary contributions to GW required predict impact flare timings 287. develop an approach incorporates this effect into BBH...
The Optical Monitoring Camera (OMC) will observe the optical emission from prime targets of gamma-ray instruments onboard ESA mission INTEGRAL, with support JEM-X monitor in X-ray domain. This capability provide invaluable diagnostic information on nature and physics sources over a broad wavelength range. Its main scientific objectives are: (1) to observed by gamma- instruments, measuring time intensity structure for comparison variability at high energies, (2) brightness position...
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...
Abstract We present the results of our power spectral density analysis for BL Lac object OJ 287, utilizing Fermi -LAT survey at high-energy γ -rays, Swift -XRT in X-rays, several ground-based telescopes and Kepler satellite optical, radio GHz frequencies. The light curves are modeled terms continuous-time autoregressive moving average (CARMA) processes. Owing to inclusion data, we were able construct first time optical variability spectrum a blazar without any gaps across ∼6 dex temporal Our...
Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31. This prediction was based detailed general relativistic modeling of trajectory around primary and its accretion disk. The expected termed Eddington to commemorate centennial celebrations now-famous solar eclipse observations test relativity by Sir Arthur Eddington. We analyze multi-epoch Spitzer between 31 September...
Abstract We report the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in blazar OJ 287. In binary black hole model, it is associated with an impact secondary accretion disk primary. Our multifrequency observing campaign was set up to search for such signature based prediction made 8 yr earlier. The first I -band results have already been reported by Kishore et al. (2024). Here we combine these data our monitoring R -band. There big change – spectral index 1.0 ± 0.1...
In its nearly regular cycle of outbursts the quasar OJ 287 is due for another outburst season in 2006-2010. The prediction exact timing depends on adopted model. precessing binary model Lehto and Valtonen time delay between impact primary disk when impacted gas becomes optically thin. turn properties accretion disk, rate, viscosity parameter α, which are not exactly known. We study flexibility provided by uncertainties. order to fix model, two methods used: wobble jet, induced secondary,...
The compact binary system in OJ287 is modeled to contain a spinning primary black hole with an accretion disk and non-spinning secondary hole. Using post-Newtonian (PN) accurate equations that include 2.5PN contributions, the leading-order general relativistic classical spin–orbit terms, orbit of calculated as expected it depends on spin orbital solution, specific times when crosses are evaluated such record observed outbursts from 1913 up 2007 reproduced. timings quite sensitive value. In...
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of secondary supermassive black hole (SMBH) impacting the accretion disc more massive primary SMBH in binary system. is not rigid but rather bends calculable way due to tidal influence secondary. Below we refer this phenomenon variable level. We begin by showing that these flares occur at times predicted simple analytical formula, based on general relativity inspired...
Context . Gamma-ray bursts (GRBs) are ideal probes of the Universe at high redshift (ɀ), pinpointing locations earliest star-forming galaxies and providing bright backlights with simple featureless power-law spectra that can be used to spectrally fingerprint intergalactic medium host galaxy during period reionization. Future missions such as Gamow Explorer (hereafter Gamow) being proposed unlock this potential by increasing rate identification high-ɀ (ɀ > 5) GRBs in order rapidly trigger...
We briefly present selected results in the field of X-ray optics obtained within project at CTU Prague collaboration with other Czech Institutes, mainly Rigaku Prague, where modules were assembled. These efforts covered simulations and designs LE (Lobster Eye) KB (Kirkpatrick-Baez) optical Systems, a study new alternative simulation/ray tracing methods, studies alternative/improved coatings, improved substrates (Si float glass), design assembly test both based on Multi Foil Technology (glass...
We describe the scientific potential of a Soft X-ray Imager (SXI) onboard ESA–CAS satellite SMILE to study activity cosmic sources in soft region and located fields planned be observed by SXI. used 2–3 keV band flux monitor MAXI/ISS, covering at least part expected SXI/SMILE telescope. discuss how SXI can contribute this branch combining data with those obtained other satellites on same days helpful if light curves 1-day means are used. show these possibilities several examples (Vela X-1...
This paper presents the results of tests a one-dimensional Schmidt lobster-eye prototype module. The optics benefits from new technology used for mechanical part which ensures accurate positioning individual mirrors, resulting in sharp image focal plane. is designed X-ray energy around 1 keV, but it was tested visible spectrum. FWHM determined. experimental agree well with simulations
Broad-band (ultraviolet to near-infrared) observations of the intense gamma ray burst GRB 990123 started ∼8.5 hours after event and continued until 18 February 1999. When combined with other data, in particular from Robotic Telescope Transient Source Experiment (ROTSE) Hubble Space (HST), evidence emerges for a smoothly declining light curve, suggesting some color dependence that could be related cooling break passing ultraviolet-optical band at about 1 day high-energy event. The steeper...
Observations of the extraordinarily bright optical afterglow (OA) GRB 991208 started 2.1 d after event. The flux decay constant OA in R-band is -2.30 +/- 0.07 up to 5 d, which very likely due jet effect, and that it followed by a much steeper with -3.2 0.2, fastest one ever seen OA. A negative detection several all-sky films taken simultaneously event implies either previous additional break prior 2 occurrence (as expected from effect). existence second might indicate steepening electron...
In Spring 2005, the blazar 3C 454.3 underwent a dramatic outburst at all wavelengths from mm to X-rays. This prompted INTEGRAL observations, accomplished in 15-18 May 2005. The source was detected by instruments 3 200 keV bright state ( erg s-1 cm-2), least factor of 2-3 higher than previously observed. is one brightest detections achieved INTEGRAL. During 2.5 days monitoring, we ~20% decrease hard X-rays (20-40 keV), indicating that have sampled decaying part flare. less apparent soft (5-15...
The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio by Whole Earth Blazar Telescope (WEBT) collaboration organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra INTEGRAL in mid-January, additional coverage RXTE Swift XRT. In this paper we focus on results WEBT campaign. source exhibited substantial variability optical flux spectral shape, a characteristic timescale few days....
We examine the ability to test black hole no-hair theorem at 10% level in this decade using binary OJ287. In we constrain value of dimensionless parameter q that relates scaled quadrupole moment and spin primary hole: q2 = -q 2 . At present can say 1 \pm 0.3 (one), agreement with General Relativity theorems. demonstrate result be improved if more observational data is found historical plate archives for 1959 1971 outbursts. also show predicted 2015 2019 outbursts will crucial improving...