Scientific results

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 →

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 →

The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds a critical value known as the Eddington limit. read more →

The flux density spectra of cyclotron sources above the sunspots were obtained by observations with RATAN-600 in the range of 1.7–10 cm with high spectral resolution and their spectral indices were estimated.  read more →

The article discusses the prospects for developing the observational base at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) for astrophysical research in the millimeter-wave range.  read more →

The results of the analysis of 205 brightest sources, which were found in the sky survey at the declination of the pulsar in the Crab Nebula, are presented. read more →

We present a study of the radio variability of bright, S1.4≥100 mJy, high-redshift quasars at z≥3 on timescales of up to 30–40 yrs. The study involved simultaneous RATAN-600 measurements at the frequencies of 2.3, 4.7, 8.2, 11.2, and 22.3 GHz in 2017–2020.  read more →

We carry out 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. We have detected the activity from the microquasar Cygnus X-3 on 27 March after the long period of the very low hard X-ray state at 15-50 keV, named by a hyper-soft state, as according to the Swift/BAT public domain data. read more →

Based on the collected multiwavelength data, namely in the radio (NVSS, FIRST, RATAN-600), IR (WISE), optical (Pan-STARRS), UV (GALEX), and X-ray (ROSAT, Swift-XRT) ranges, we have performed a cluster analysis for the blazars of the Roma-BZCAT catalog. read more →

The microquasar Cyg X-3 entered in the hyper-soft X-ray state in mid January 2024 (Swift/BAT monitor). Bright radio flares of different intensity were observed by the Nasu telescope array (ATels #16455, #16520) and with the Allen Telescope Array (ATA; ATel #16466) in February 2024. read more →

Context : Understanding the mechanisms that launch and shape powerful relativistic jets from supermassive black holes (SMBHs) in high-redshift active galactic nuclei (AGN) is crucial for probing the co-evolution of SMBHs and galaxies over cosmic time. read more →

The blazar Ton 599 showed the strongest radio flares in its history almost a year ago, in February 2023 (#ATels 15872, 15873, 15894).  read more →

We present the results of our observations using the Giant Meterwave Radio Telescope (GMRT) to investigate the radio continuum and OH line emission of 10 OHM candidates from the Arecibo Legacy Fast ALFA (ALFALFA) survey.  read more →

Eurasian patent for an invention has been received: Method for generating a catalog of measurements of radio emission parameters from blazars. read more →

Patent has been received for an invention: Method for measuring the parameters of radio emission from blazars to form a catalog of them. read more →

<div>Study of high-redshift radio galaxies (HzRGs) can shed light on the active galactic nuclei (AGNs) evolution in massive elliptical galaxies. The vast majority of observed high-redshift AGNs are quasars, and there are very few radio galaxies at redshifts z>3.</div>
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Aims. The X-ray luminous and radio-loud AGN SRGE J170245.3+130104 discovered at z ∼ 5.5 provides unique chances to probe the SMBH growth and evolution with powerful jets in the early Universe. read more →