A5083812874- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Radio Astronomy Observations and Technology
- Stellar, planetary, and galactic studies
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Relativity and Gravitational Theory
- Astronomical Observations and Instrumentation
- Atmospheric Ozone and Climate
- Radioactive Decay and Measurement Techniques
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Superconducting and THz Device Technology
- Astro and Planetary Science
- Statistical and numerical algorithms
- History and Developments in Astronomy
- Atomic and Molecular Physics
- Gyrotron and Vacuum Electronics Research
- Scientific Measurement and Uncertainty Evaluation
Special Astrophysical Observatory
2013-2024
University of Cambridge
2013-2024
Development Agency of Serbia
2024
St Petersburg University
2023
Kazan Federal University
2015-2021
Institute of Physics
2021
Russian Academy of Sciences
2010-2016
Space Research Institute
2015
Agenzia Spaziale Italiana
2012
Aalto University
2012
Context. The planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. CMB intensity and polarization that are its prime targets contaminated by foreground emission.
The Square Kilometre Array Observatory (SKAO) will explore the radio sky to new depths in order conduct transformational science. SKAO data products made available astronomers be correspondingly large and complex, requiring application of advanced analysis techniques extract key science findings. To this end, is conducting a series Science Data Challenges, each designed familiarise scientific community with drive development techniques. We present results from Challenge 2 (SDC2), which...
A harmonic-space maximum-entropy method (MEM) is presented for separating the emission from different physical components in all-sky observations by forthcoming Planck satellite. The analysis performed at full resolution, with a pixel size of 1.7 arcmin, which corresponds to ℓmax≈ 6000. simulated data include cosmic microwave background (CMB), kinetic and thermal Sunyaev–Zel'dovich (SZ) effects galaxy clusters, as well Galactic dust, free–free synchrotron emission. Our simulations also...
We present a study of the radio variability bright, $S_{1.4}\geq100$ mJy, high-redshift quasars at $z\geq3$ on timescales up to 30-40 years. The involved simultaneous RATAN-600 measurements frequencies 2.3, 4.7, 8.2, 11.2, and 22.3 GHz in 2017-2020. In addition, data from literature were used. have found that index, $V_S$, which quantifies normalized difference between maximum minimum flux density while accounting for measurement uncertainties, ranges 0.02 0.96 quasars. Approximately half...
We present an extension of the harmonic-space maximum-entropy component separation method (MEM) for multifrequency cosmic microwave background observations that allows one to perform with more plausible assumptions about receiver noise and foreground astrophysical components. Component is considered in presence spatially varying variance spectral properties It shown that, if not taken properly into account, spectra, particular, can severely reduce accuracy separation. Nevertheless, by...
We present observations and analysis of a sample 123 galaxy clusters from the 2013 Planck catalogue Sunyaev-Zel'dovich sources with Arcminute Microkelvin Imager (AMI), ground-based radio interferometer. AMI provides an independent measurement higher angular resolution, 3 arcmin compared to beams 5-10 arcmin. The thus provide validation cluster detections, improved positional estimates, consistency check on fitted 'size' ($\theta_{s}$) 'flux' ($Y_{\rm tot}$) parameters in Generalised Navarro,...
ABSTRACT We present the radio properties of optically selected quasars with z ≥ 3. The complete sample consists 102 a flux density level S1.4 100 mJy in declination range −35° ≤ Dec. +49°. observations were obtained 2017–2020 using telescope RATAN-600. measured densities at six frequencies 1.2, 2.3, 4.7, 8.2, 11.2, and 22 GHz quasi-simultaneously uncertainties 9–31 per cent. detection rate is 100, 89, 46 cent GHz, respectively. have analysed averaged spectra based on RATAN literature data....
We present a harmonic model for the data analysis of an all-sky cosmic microwave background survey, such as Planck, where survey is obtained through ring-scans sky. In this model, resampling and pixelisation are avoided. The spherical transforms sky at each frequency, in total intensity polarization, well bright-point-source catalogue, derived directly from reduced onto rings. Formal errors most significant correlation coefficients frequency maps preserved. A clean transparent path original...
A flexible maximum-entropy component separation algorithm is presented that accommodates anisotropic noise, incomplete sky-coverage and uncertainties in the spectral parameters of foregrounds. The capabilities method are determined by first applying it to simulated spherical microwave data sets emulating COBE-DMR, COBE-DIRBE Haslam surveys. Using these simulations we find very difficult determine unambiguously galactic components for this set due their high level noise. Nevertheless, show...
We report the first detection at 4.7 and 8.2 GHz with RATAN-600 radio telescope of source PSO J047.4478+27.2992, which has been announced as a blazar z=6.1. The average flux density is $12\pm3$ $8\pm4$ mJy respectively, an upper limit estimated 3 11.2 GHz. light curve GHz, obtained on time-scale four months, exhibits moderate variability (fractional $F_{var}=0.28\pm0.02$). new measurements extend previous literature data to higher frequencies, indicating single power-law spectrum...
ABSTRACT We present a study of the multiwavelength (MW) variability blazar AO 0235$+$164 based on radio-to-$\gamma$-ray data covering long time period from 1997 to 2023. The radio are represented by 1–22 GHz measurements SAO RAS RATAN-600 telescope, 5 and 8 IAA RT-32 telescopes, 37 RT-22 telescope CrAO RAS. optical in R-band were collected with 1-m Zeiss-1000 0.5-m AS-500/2 telescopes. Additionally, we used archive at 230 Submillimetre Array $\gamma$-ray 0.1–100 GeV band Fermi-LAT point...
A survey of the North Celestial Pole region using RATAN-600 radio telescope at five frequencies in range 2.3 to 21.7 GHz is described. Sources were chosen from NVSS catalogue. The flux densities 171 sources Declination +75 +88 are presented; typical density errors 5-10 percent including calibration errors. About 20 have flat spectra or a component.
We present a study of the radio continuum properties two luminous/ultraluminous infrared galaxy samples: OH megamaser (OHM) sample (74 objects) and control (128 without detected maser emission. carried out pilot observations for 140 objects with telescope RATAN-600 at 1.2, 2.3, 4.7, 8.2, 11.2, 22.3 GHz in 2019-2021. The OHM has times more flat-spectrum sources (32 per cent) than sample. Steep spectra prevail both samples. median spectral index 4.7 $\alpha_{4.7}=-0.59$ sample,...
We present an optical-to-radio study of the BL Lac object S4 0954+658 observations during 1998-2023. The measurements were obtained with SAO RAS Zeiss-1000 1-m and AS-500/2 0.5-m telescopes in 2003-2023, RATAN-600 radio telescope at 1.25 (0.96, 1.1), 2.3, 4.7 (3.7, 3.9), 8.2 (7.7), 11.2, 22.3 (21.7) GHz 1998-2023, IAA RT-32 Zelenchukskaya Badary 5.05 8.63 2020--2023, RT-22 single-dish CrAO 36.8 2009-2023. In this period blazar had been showing extremely high broadband activity variability...
We present a study of the radio variability bright, $S_{1.4}\geq100$ mJy, high-redshift quasars at $z\geq3$ on timescales up to 30--40 years. The involved simultaneous RATAN-600 measurements frequencies 2.3, 4.7, 8.2, 11.2, and 22.3 GHz in 2017--2020. In addition, data from literature were used. have found that index $V_S$ ranges 0.02 0.96, with about half objects sample showing range 0.25--0.50, which is comparable blazars lower redshifts. distribution significantly different 2.3--11.2 GHz,...
We present a study of the multiwavelength (MW) variability blazar AO 0235+164 based on radio-to-$\gamma$-ray data covering long time period from 1997 to 2023. The radio are represented by 1-22 GHz measurements RATAN-600 telescope, 5 and 8 RT-32 telescopes, 37 RT-22 telescope. optical in $R$-band were collected with 1-m Zeiss-1000 0.5-m AS-500/2 telescopes. Additionally we used archive at 230~GHz SMA $\gamma$-ray 0.1-100 GeV band Fermi-LAT point source 4FGL-DR2 catalogue. properties during...
We present a study of the multiwavelength (MW) variability blazar AO 0235+164 based on radio-to-$\gamma$-ray data covering period from 1997 to 2023. The radio are represented by measurements SAO RAS, IAA and CrAO RAS telescopes. optical were collected with 1-m 0.5-m reflectors. archive at 230 GHz Submillimeter Array $\gamma$-ray Fermi-LAT mission used too. A significant correlation between different spectral bands is found time delays up 1.7 years. relation delay frequency well described...