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About Search of Pulse Emission from Magnetar SGR1935+2154 at LPA LPI

Transactions of IAA RAS, issue 63, 3–7 (2022)

Keywords: fast radio bursts, dispersion measure, SGR1935+2154

Abstract

The magnetar is known as a source of soft gamma radiation. For the first time, radio emission from SGR1935+2154 in the form of a hyperflare was detected at a frequency of 1.25 GHz using the FAST radio telescope in May 2020. A check of the previously published (Fedorova, Rodin, 2020) pulse from the magnetar SGR1935+2154 was carried out. The magnetar enters the survey conducted on the Large Phased Array (LPA) radio telescope at a frequency of 111 MHz. The data received on the LPA is recorded in parallel in two modes having low and high frequency-time resolution: 6 channels with a channel width of 415 kHz and a time resolution of Δt = 100 ms; 32 channels with a channel width of 78 kHz and a time resolution of Δt = 12.5 ms. The original search was carried out using data with low time-frequency resolution. The search for dispersed signals in the meter wavelength range is difficult, compared with the search in the decimeter range, due to scattering proportional to the fourth power of frequency and dispersion smoothing of the pulse in frequency channels proportional to the second power of frequency. In order to collect a broadened pulse signal and obtain the best value of the signal-to-noise ratio (S/N), the search was carried out using an algorithm based on the convolution of multichannel data with a scattered pulse pattern. The shape of the template corresponds to the shape of a scattered pulse with a dispersion measure (DM) of 375 $pc/cm^3$. For repeated verification, the same data was used in which the pulse from the magnetar was detected. An additional check of the published pulse was also carried out using data with a higher frequency-time resolution. Since the dispersion smoothing in the frequency channel in the 32-channel data is 5 times less than in the 6-channel data, an increase approximately 2 times in the S/N pulse could be expected. Pulse radiation with S/N > 4 having a pulse peak shift depending on DM from SGR1935+2154 was not detected in either 32-channel or 6-channel data.

Citation

Text

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RIS

E. A. Brylyakova, S. A. Tyul’bashev. About Search of Pulse Emission from Magnetar SGR1935+2154 at LPA LPI // Transactions of IAA RAS. — 2022. — Issue 63. — P. 3–7.

@article{brylyakova2022,
  abstract = {The magnetar is known as a source of soft gamma radiation. For the first time, radio emission from SGR1935+2154 in the form of a hyperflare was detected at a frequency of 1.25 GHz using the FAST radio telescope in May 2020. A check of the previously published (Fedorova, Rodin, 2020) pulse from the magnetar SGR1935+2154 was carried out.
The magnetar enters the survey conducted on the Large Phased Array (LPA) radio telescope at a frequency of 111 MHz. The data received on the LPA is recorded in parallel in two modes having low and high frequency-time resolution: 6 channels with a channel width of 415 kHz and a time resolution of Δt = 100 ms; 32 channels with a channel width of 78 kHz and a time resolution of Δt = 12.5 ms. The original search was carried out using data with low time-frequency resolution. The search for dispersed signals in the meter wavelength range is difficult, compared with the search in the decimeter range, due to scattering proportional to the fourth power of frequency and dispersion smoothing of the pulse in frequency channels proportional to the second power of frequency. In order to collect a broadened pulse signal and obtain the best value of the signal-to-noise ratio (S/N), the search was carried out using an algorithm based on the convolution of multichannel data with a scattered pulse pattern. The shape of the template corresponds to the shape of a scattered pulse with a dispersion measure (DM) of 375 $pc/cm^3$. For repeated verification, the same data was used in which the pulse from the magnetar was detected. An additional check of the published pulse was also carried out using data with a higher frequency-time resolution. 
Since the dispersion smoothing in the frequency channel in the 32-channel data is 5 times less than in the 6-channel data, an increase approximately 2 times in the S/N pulse could be expected. Pulse radiation with S/N > 4 having a pulse peak shift depending on DM from SGR1935+2154 was not detected in either 32-channel or 6-channel data.},
  author = {E.~A. Brylyakova and S.~A. Tyul’bashev},
  doi = {10.32876/ApplAstron.63.3-7},
  issue = {63},
  journal = {Transactions of IAA RAS},
  keyword = {fast radio bursts, dispersion measure, SGR1935+2154},
  pages = {3--7},
  title = {About Search of Pulse Emission from Magnetar SGR1935+2154 at LPA LPI},
  url = {http://iaaras.ru/en/library/paper/2135/},
  year = {2022}
}

TY  - JOUR
TI  - About Search of Pulse Emission from Magnetar SGR1935+2154 at LPA LPI
AU  - Brylyakova, E. A.
AU  - Tyul’bashev, S. A.
PY  - 2022
T2  - Transactions of IAA RAS
IS  - 63
SP  - 3
AB  - The magnetar is known as a source of soft gamma radiation. For the
first time, radio emission from SGR1935+2154 in the form of a
hyperflare was detected at a frequency of 1.25 GHz using the FAST
radio telescope in May 2020. A check of the previously published
(Fedorova, Rodin, 2020) pulse from the magnetar SGR1935+2154 was
carried out.  The magnetar enters the survey conducted on the Large
Phased Array (LPA) radio telescope at a frequency of 111 MHz. The
data received on the LPA is recorded in parallel in two modes having
low and high frequency-time resolution: 6 channels with a channel
width of 415 kHz and a time resolution of Δt = 100 ms; 32 channels
with a channel width of 78 kHz and a time resolution of Δt = 12.5 ms.
The original search was carried out using data with low time-
frequency resolution. The search for dispersed signals in the meter
wavelength range is difficult, compared with the search in the
decimeter range, due to scattering proportional to the fourth power
of frequency and dispersion smoothing of the pulse in frequency
channels proportional to the second power of frequency. In order to
collect a broadened pulse signal and obtain the best value of the
signal-to-noise ratio (S/N), the search was carried out using an
algorithm based on the convolution of multichannel data with a
scattered pulse pattern. The shape of the template corresponds to the
shape of a scattered pulse with a dispersion measure (DM) of 375
$pc/cm^3$. For repeated verification, the same data was used in which
the pulse from the magnetar was detected. An additional check of the
published pulse was also carried out using data with a higher
frequency-time resolution.   Since the dispersion smoothing in the
frequency channel in the 32-channel data is 5 times less than in the
6-channel data, an increase approximately 2 times in the S/N pulse
could be expected. Pulse radiation with S/N > 4 having a pulse peak
shift depending on DM from SGR1935+2154 was not detected in either
32-channel or 6-channel data.
DO  - 10.32876/ApplAstron.63.3-7
UR  - http://iaaras.ru/en/library/paper/2135/
ER  -