Scientific results

We report on a detailed study of a luminous, heavily obscured (NH ~ 2 × 10^23 cm^-2), radio-loud quasar SRGA J230631.0+155633 discovered in the 4-12 keV energy band by the Mikhail Pavlinsky ART-XC telescope aboard the SRG observatory during the first two years of its all-sky X-ray survey in 2020-2021. read more →

The significant brightening of the flat spectrum radio quasar OP 313 (BZU J1310+3220, 4FGL J1310.5+3221) was recently been reported in gamma-ray (ATel #17167), near-infrared (ATel #17179) and optical bands (ATel #17173, #17184, #17185) over the past two weeks. read more →

We present the results of a three-year X-ray, optical, and radio polarimetric monitoring campaign of the prototypical black hole X-ray binary Cyg X-1, conducted from 2022 to 2024.  read more →

The advancement of observational technologies and software for processing and visualizing spectro-polarimetric microwave data obtained with the RATAN-600 radio telescope opens new opportunities for studying the physical characteristics of solar plasma at the levels of the chromosphere and corona. read more →

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In 2024 the enhanced gamma-ray activity from 3C 138, also known as 4FGL J0521.2+1637, was observed with the Fermi/LAT (Large Area Telescope) (ATel #16845). read more →

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High-redshift active galactic nuclei (AGN) provide key insights into early supermassive black hole growth and cosmic evolution. This study investigates the parsec-scale properties of 86 radio-loud quasars at z ≥ 3 using very long baseline interferometry (VLBI) observations. read more →

The KM3NeT experiment reported the detection of an ultra-high-energy neutrino with an energy estimate of ~ 220 PeV, the most energetic yet observed.  read more →

During current long-term monitoring of microquasars we have detected the bright flare from the microquasar GRS1915+105 with the RATAN-600 radio telescope. read more →

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Analysis of more than 300 M-class solar flares observed with the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory in the 131 Å channel, revealed 16 events of sloshing oscillations in hot solar coronal loops. read more →

The existence of continuous cooling and heating processes is an important condition governing the behavior of the solar corona, which is characterized by temperatures of several million Kelvin. These processes can be significantly influenced by small-scale coronal formations, which largely determine the thermal balance of the corona and solar-wind disturbances.  read more →

Blazars are beamed active galactic nuclei (AGNs) known for their strong multi-wavelength variability on timescales ranging from years down to minutes. Many different models have been proposed to explain this variability. read more →

We present a study of the multiwavelength (MW) variability of the blazar AO 0235+164 based on the radio-to-γ-ray data covering a long time period from 1997 to 2023. The radio data are represented by the 1-22 GHz measurements from the SAO RAS RATAN-600 radio telescope, the 5 and 8 GHz data from the IAA RAS RT-32 telescopes, and the 37 GHz data from the RT-22 telescope of CrAO RAS. read more →

The flat-spectrum radio quasar PKS 2126-15, located at z=3.26, has been identified as one of the first high frequency peaker (HFP) objects with a maximum in its radio spectrum around 8 GHz. It is represented in the BLcat catalogue of blazars monitored with the RATAN-600 radio telescope at 1.2-22.3 GHz since the 2000s. read more →

When observing the Sun with RATAN-600 radio telescope using a spectropolarimetric complex in the range 1–3 GHz, as well as when observing coronal rain, absorption in the radio emission was discovered in the spectral region 1.5–1.65 GHz in active solar regions located under a cold filament or on the limb under a prominence. read more →

We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May–June. read more →

We continue the long-term multi-frequency monitoring of the Galactic microquasars with the RATAN-600 radio telescope almost daily in 2024 at 1.24-30 GHz. read more →

We present Very Long Baseline Array observations of radio continuum and OH line emission toward the OH megamaser (OHM) galaxy IRAS 01298−0744. read more →

In February 2023 we reported the historical high flux density level of the flat-spectrum radio quasar Ton 599 (4C +29.45) at 1.2-36.8 GHz (ATel #15894).  read more →