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V. A. Potapov

Publications and source records attributed to V. A. Potapov.

5 recordsLinked to original sources
arXiv2025

Pushchino multibeam pulsar search. VII. The results of the timing of 12 slow pulsars

We have performed timing of a number of known slow pulsars with poorly known coordinates and parameters of their intrinsic rotation. We used data from the archive of round-the-clock monitoring observations on the third (stationary) beam pattern of the Large Phased Array radio telescope (LPA LPI) at a frequency of 111 MHz, which has an unsatisfactory connection of the local quartz time standards to the reference scale (UTC). To compensate for the resulting errors, we applied an algorithm previously developed by us, which uses Pulsar Timescale as an intermediate reference scale to compute corrections to the pulses Times of Arrival (TOAs) measured by the local clocks and to switch to UTC. Analyzing a ten-year observational data set we substantially refined the rotational and astrometric parameters of 12 pulsars. The spin frequencies $ν$ and their first derivatives $\dotν$ were determined with accuracies of $10^{-10}$ Hz and $10^{-19}$ s$^{-2}$, respectively, which is 5-6 orders of magnitude better than the values quoted in the catalogue. The coordinates are determined with accuracies ranging from units to tens of arcseconds.

astro-ph.HE↗
arXiv2025

Pushchino multibeam pulsar search VI. Method of pulsar timing using bad timed data

A method for pulsar timing based on monitoring data from the 3-th diagramm of the Large Phased Array (LPA LPI) radio telescope is proposed. In our observations, recorders with quartz clock generators were used as local clocks. Such recorders initially had an accuracy and hardware reference to the UTC time scale insufficient for pulsar timing. We have developed a method for referencing such clocks to the UTC based on observations of known pulsars used as intermediate reference clocks. This allowed us to improve dramatically the accuracy of determining the Time of Arrivals (TOA) of pulsars' pulses. We applied this method to the results of our observations of 24 second period pulsars over a time interval of 10 years. It was shown that the accuracy of the pulsar period, its first derivative ($P$ and $\dot P$) and their coordinates in right ascension and declination ($α, δ$) allow us to predict the pulsar phase within $\pm 0.5 P$ during several years. The accuracy of determining the coordinates by right ascension and declination was typically better than $10^{\prime \prime}$ with an angular resolution of the radio telescope of about $30^\prime$. That makes it possible to use these parameters for timing using radio telescopes with narrow beam patterns. The accuracy of the calculated period was typically better than $10^{-8}$~s.

astro-ph.HE↗
arXiv2022

On long-term variations of solar wind parameters and solar activity

Comparison is carried out of the long term variation of the year averaged solar wind speed and interplanetary scintillation index with the variations of Wolf's numbers and A_P indexes of geomagnetic activity for the data of 20-24 solar activity cycles. It is shown that the slow non-monotonous trend in the scintillation parameters at middle and high heliolatitudes exists with the typical scale of order of century cycle. Correlation between the variations of Wolf's numbers and anomalies of the air temperature is analyzed for long data series from 1610 up to the present time. Possible application of the results to the global climate problem is discussed.

physics.space-ph↗
arXiv2020

Irregularities in the rate of generation of giant pulses from the Crab pulsar observed at 111 MHz

We present analysis of the rate of giant radio pulses (GPs) emission from the Crab pulsar (B0531+21). Results of our 9 years daily observations with the Large Phased Array radio telescope of Pushchino Radio Astronomy Observatory at 111 MHz were used. Limited sample of 8753 strong individual pulses in 2004 observational sessions was further analysed. It was shown that the observed monthly averaged rate of GPs emission was highly unstable during the entire span of observations and changes by about two orders of magnitude for high-energy pulses. Data were further analysed to search for the possible connection between pulsar glitches and the process of GP emission. We have found a significant increase in the rate of emission of high-energy GPs after MJD 58064, when the largest glitch ever observed in the Crab pulsar was happened. Although considerable changes in GPs emission rate could have been caused by the propagation effects in the nebula itself, we have found that the pulsar had demonstrated high degree of intrinsic irregularity of high-energy pulses emission over long time intervals.

astro-ph.HE↗