A5061592714- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- Ionosphere and magnetosphere dynamics
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- Satellite Communication Systems
- Veterinary Equine Medical Research
- Computational Physics and Python Applications
- Security, Politics, and Digital Transformation
- Antenna Design and Optimization
- Muscle activation and electromyography studies
- Optical Wireless Communication Technologies
- Optical Network Technologies
Institute of Applied Astronomy
2012-2024
Technische Universität Berlin
2022
GFZ Helmholtz Centre for Geosciences
2022
Aalto University
2022
Geoscience Australia
2022
Broad Institute
2015
Russian Academy of Sciences
2011-2014
Very long baseline interferometric (VLBI) localisations of repeating fast radio bursts (FRBs) have demonstrated a diversity local environments: from nearby star-forming regions to globular clusters. Here we report the VLBI localisation FRB 20201124A using an ad-hoc array dishes that also participate in European Network (EVN). In our campaign, detected 18 total at two separate epochs. By combining visibilities both observing epochs, were able localise with 1-$\sigma$ error 4.5 milliarcseconds...
This paper presents the past, present and future status of Russian VLBI network "Quasar". has been developed for at least 20 years by Institute Applied Astronomy Academy Sciences (IAA RAS). The equipment installed currently each "Quasar" station facilities processing observational data are described briefly. latest results presented, including Earth orientation parameters (EOP) determined from comparison with those other centers. Our plans to extend east west will be carried out establishing...
Abstract Radio-loud quasars at high redshift ( z ≥ 4) are rare objects in the universe and rarely observed with Very Long Baseline Interferometry (VLBI). But some of them have flux density sufficiently for monitoring their apparent position. The instability astrometric positions could be linked to astrophysical process jetted active galactic nuclei early universe. Regular observations high-redshift used estimating proper motion over several years. We undertaken regular VLBI 2.3 GHz S band)...
Astrometric positions of radio-emitting active galactic nuclei (AGNs) can be determined with sub-milliarcsec accuracy using very long baseline interferometry (VLBI). The usually small apparent proper motion distant extragalactic targets allow us to realize the fundamental celestial reference frame VLBI observations. However, long-term astrometric monitoring may reveal extreme changes in some AGN positions. Using new observations 2018-2021, we show here that four radio sources (3C48, CTA21,...
The high brightness temperatures, $T_\mathrm{b}\gtrsim 10^{13}$ K, detected in several active galactic nuclei by RadioAstron space VLBI observations challenge theoretical limits. Refractive scattering the interstellar medium may affect such measurements. We quantify properties and sub-mas scale source parameters for quasar B0529+483. Using correlated flux density measurements at 1.7, 4.8, 22 GHz on projected baselines up to 240,000 km we find two characteristic angular scales core, about 100...
Context. Radio-loud active galactic nuclei in the early Universe are rare. The quasars J0906+6930 at redshift z=5.47 and J2102+6015 z=4.57 stand out from known sample with their compact emission on milliarcsecond (mas) angular scale high (0.1-Jy level) flux densities measured GHz radio frequencies. This makes them ideal targets for very long baseline interferometry (VLBI) observations. Aims. By means of VLBI imaging we can reveal inner structure model brightness distribution to better...
ABSTRACT There is still a limited number of high-redshift (z > 3) active galactic nuclei (AGNs) whose jet kinematics have been studied with very long baseline interferometry (VLBI). Without dedicated proper motion survey, regularly conducted astrometric VLBI observations bright radio-emitting AGN sensitive arrays can be utilized to follow changes in the jets, by means high-resolution imaging and brightness distribution modelling. Here, we present first-time kinematic study NVSS...
Aims . We investigated the residual orientation offset and spin between bright ( G ≤ 13 mag) frame of Gaia Early Data Release 3 EDR3) third realization International Celestial Reference Frame (ICRF3). For this purpose, six rotation parameters (orientation its time derivative, spin), as well corrections to astrometric model for each star involved, are fitted differences in models derived from very long baseline interferometry (VLBI) This study aims find reliable estimates two frames. Methods...
Abstract We present the localization and host galaxy of FRB 20190208A, a repeating source fast radio bursts (FRBs) discovered using CHIME/FRB. As part Pinpointing REpeating ChIme Sources with EVN dishes repeater program on European VLBI Network (EVN), we monitored 20190208A for 65.6 hr at ∼1.4 GHz detected single burst, which led to its very long baseline interferometry 260 mas uncertainty (2 σ ). Follow-up optical observations MMT Observatory ( i ≳ 25.7 mag (AB)) found no visible position....
Context. We highlight the capabilities of geodetic VLBI technique to test General relativity in classical astrometric style, i.e., measuring deflection light vicinity Sun. Aims. In previous studies, parameter was estimated by global analyses thousands sessions. Here we estimate from a single session where Sun has approached two strong reference radio sources 0229+131 and 0235+164 at an elongation angle 1-3 degrees. Methods. The AUA020 1 May 2017 designed obtain more than 1000 group delays...
Jets of high-redshift active galactic nuclei (AGNs) can be used to directly probe the activity black holes in early Universe. Radio sources with jets misaligned respect line sight are expected dominate AGN population. In this paper, we present high-resolution imaging results a z=4.57 J2102+6015 by analyzing its multi-epoch dual-frequency very long baseline interferometry (VLBI) data. The 8.4-GHz VLBI images reveal two major features along east-west direction separated $\sim$ 10 milli-arcsec...
We present here the East Asia to Italy Nearly Global VLBI (EATING VLBI) project. How this project started and evolution of international collaboration between Korean, Japanese, Italian researchers study compact sources with observations is reported. Problems related synchronization very different arrays technical details telescopes involved are presented discussed. The relatively high observation frequency (22 43 GHz) long baselines produced high-resolution images. example images demonstrate...
One of the most accurate and effective ways to control gestures is muscle activity, which occurs with any movement. Electromyography (EMG) used record such activity. This article compares SVM classification algorithms, perceptron, random trees method density probability in relation EMG signal. Arduino Leonardo a single-channel Shield The aim this paper prove possibility creating cheap accessible biointerface based on
The Sun's corona has interested researchers for multiple reasons, including the search solution famous coronal heating problem and a purely practical consideration of predicting geomagnetic storms on Earth. There exist numerous different theories regarding solar corona; therefore, it is important to be able perform comparative analysis validation those theories. One way that could help us move towards answers problems observational methods obtain information about physical properties provide...
There is still a limited number of high-redshift ($z>3$) active galactic nuclei (AGN) whose jet kinematics have been studied with very long baseline interferometry (VLBI). Without dedicated proper motion survey, regularly conducted astrometric VLBI observations bright radio-emitting AGN sensitive arrays can be utilized to follow changes in the jets, by means high-resolution imaging and brightness distribution modeling. Here we present first-time kinematic study NVSS~J080518$+$614423 ($z =...
This paper presents the results of observations giant pulses from pulsar B0531+21 (the Crab Nebula pulsar) conducted at Institute Applied Astronomy Russian Academy Sciences (RAS). The primary aim study was to establish a domestic monitoring service and compute ephemerides for this pulsar. Observations commenced in mid-2023 using RT-13 telescopes Quasar-KVO network, operating S, X, Ka bands. To achieve research goals, we utilized VLBI (Very-Long-Baseline Interferometry) registration system...