Pushchino Multibeam Pulsar Search. X. Observations of pulsars at declinations above $+53^o$

TL;DR

The study demonstrates a low‑frequency pulsar survey strategy (PUMPS) using the LPA1 array at $110.4$ MHz, focusing on declinations $δ>+53^{ angle}$. By summing Fourier power spectra across multiple days and partial transits, the method achieves sensitivity gains of roughly $5$–$10$×, enabling the detection of $35$ pulsars in a blind search and flux density estimates for $33$ at $110.4$ MHz. The results reveal periods from $0.15$ s to $1.93$ s and DMs up to $156.7$ pc cm$^{-3}$, with DM and period estimates generally consistent with existing catalogs and LOFAR measurements. A majority of the studied pulsars exhibit spectral turnover or flattening at low frequency when compared to $135$ MHz data, underscoring the importance of low‑frequency spectral studies and providing a valuable dataset for pulsar population and spectral modeling at $ u \, ext{around} \, 110$ MHz.

Abstract

A search for pulsars was carried out using a Large Phased Array (LPA) radio telescope at a frequency of 110.4 MHz with a time resolution of 3.072 ms and a frequency resolution of 19.5 kHz with a 2.5 MHz bandwidth used. The survey was conducted in a site with declinations of $+53^\circ < δ< +87^\circ$. The viewing area is approximately 4100 sq.deg. The search was carried out using Fourier power spectra. To increase sensitivity, multiple observations were made in each direction in the sky, and the resulting power spectra were summarized. This made it possible to increase sensitivity by about 5-10 times, depending on the direction in the sky. A blind search opened 35 known pulsars. Estimates of the flux density for 33 pulsars have been obtained.

Figures (3)

• Figure 1: The left panel shows a $P/DM$ map of the famous pulsar J0033+5730. The intersection of the horizontal and vertical lines indicates the probable value of $P$ and $DM$. The middle panel shows the power spectrum, which corresponds to the point of intersection of the lines. The right panel shows the harmonic height in the power spectrum in units of S/N, depending on the $DM$ being tested. The maximum in this dependence corresponds to the $DM$ expected for the found pulsar. On the horizontal and vertical axes of the figures from left to right: period and dispersion measure; the number of the point in the power spectrum and the harmonic height in conventional units; the dispersion measure and signal-to-noise.
• Figure 2: Average profiles of known pulsars detected by blind search at declinations of $+53^{\circ}<\delta<+87^{\circ}$.
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