Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

A nearby pulsar J1951+2837 observed by the LPA and FAST

T. V. Smirnova, D. J. Zhou, M. A. Kitaeva, S. A. Andrianov, C. Wang, P. F. Wang, J. L. Han, S. A. Tyul'bashev

TL;DR

This work investigates PSR J1951+2837, a nearby slow pulsar with $P\approx7.334$ s that exhibits RRAT-like emission. By combining long-term LPA observations at $110$ MHz with targeted FAST observations at $1250$ MHz, the authors derive a phase-connected timing solution, refine the dispersion measure to $DM = 2.9 \pm 0.6$ pc cm$^{-3}$, and infer a distance of roughly $200$–$300$ pc. They characterize pulse-widths, polarization, RM ($-2.2\pm0.7$ rad m$^{-2}$), and a spectral index $\alpha$ around $2.5$–$3.2$ across 110–1250 MHz, revealing an exceptionally low luminosity ($L_{110}\sim0.5$–$1.0$ mJy kpc$^2$) compared with the pulsar population. The results place J1951+2837 near the death-line in the $P$–$\dot P$ diagram and illustrate the value of coordinated low- and high-frequency observations for uncovering and timing nearby, faint pulsars and RRATs.

Abstract

PSR J1951+2837 is a nearby pulsar with a period of 7.334 s and dispersion measure of DM = 2.9 $\pm$ 0.6 pc cm$^{-3}$, located about 200 or 300 pc from the Sun. It occasionally radiates bright pulses and has been observed by the Large Phased Array (LPA) radio telescope at 110 MHz and by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) at 1250 MHz. We detected only 343 pulses in 228 LPA observation sessions and 5 bright pulses in two FAST sessions. Based on the times of arrival (TOAs) of these bright pulses, we determined the coherent timing solution for this pulsar at a frequency of 110 MHz. Based on flux densities (S) of these bright pulses at two frequencies ($ν$), we found that it is probably one of the known pulsars with the lowest luminosities to date, with a spectral index of about $α$ = (2.5 - 3.2) for S $\sim ν^{-α}$.

A nearby pulsar J1951+2837 observed by the LPA and FAST

TL;DR

This work investigates PSR J1951+2837, a nearby slow pulsar with s that exhibits RRAT-like emission. By combining long-term LPA observations at MHz with targeted FAST observations at MHz, the authors derive a phase-connected timing solution, refine the dispersion measure to pc cm, and infer a distance of roughly – pc. They characterize pulse-widths, polarization, RM ( rad m), and a spectral index around – across 110–1250 MHz, revealing an exceptionally low luminosity (– mJy kpc) compared with the pulsar population. The results place J1951+2837 near the death-line in the – diagram and illustrate the value of coordinated low- and high-frequency observations for uncovering and timing nearby, faint pulsars and RRATs.

Abstract

PSR J1951+2837 is a nearby pulsar with a period of 7.334 s and dispersion measure of DM = 2.9 0.6 pc cm, located about 200 or 300 pc from the Sun. It occasionally radiates bright pulses and has been observed by the Large Phased Array (LPA) radio telescope at 110 MHz and by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) at 1250 MHz. We detected only 343 pulses in 228 LPA observation sessions and 5 bright pulses in two FAST sessions. Based on the times of arrival (TOAs) of these bright pulses, we determined the coherent timing solution for this pulsar at a frequency of 110 MHz. Based on flux densities (S) of these bright pulses at two frequencies (), we found that it is probably one of the known pulsars with the lowest luminosities to date, with a spectral index of about = (2.5 - 3.2) for S .

Paper Structure

This paper contains 12 sections, 2 equations, 5 figures, 1 table.

Table of Contents

  1. Introduction
  2. The LPA and FAST observations, data processing
  3. The LPA Observations
  4. The FAST Observations
  5. Results and discussion
  6. Estimation of the dispersion measure
  7. Pulse widths
  8. RRAT features
  9. Timing by LPA
  10. Polarization
  11. Flux density, spectral index and luminosity
  12. Conclusion

Figures (5)

  • Figure 1: Raw data for four pulses of PSR J1951+2837 recorded directly by the LPA on January 7th, 2019, summed without dispersion compensation, gain equalization, and interference mitigation. The inset shows the details of the strongest pulse.
  • Figure 2: The pulse stacks obtained from the FAST verification observations on 20230603 and 20240725. The brighter color reflects a higher intensity. The right subpanel shows the observed pulse amplitude in S/N units, with a dotted line for 3$\sigma_n$ (root mean square of the noise). The profiles summed over the entire observations from pulses with $S/N > 3 \sigma_n$ or $<3 \sigma_n$ are shown in the bottom subpanels, with the peak centered on the rotation phase 0.5.
  • Figure 3: The integrated pulse profile (in arbitrary scale) obtained by adding 33 pulses observed by LPA presented by solid line, with $W_{0.5}$ = 100 ms. The dotted line shows one individual pulse detected on May 14, 2021, having a width of $W_{0.5}$ = 37 ms.
  • Figure 4: The residual of TOAs of pulses detected by LPA and FAST after fitting the timing solution. The vertical axis shows the residual deviations in ms, and the horizontal axis is the time in modified Julian Days (MJD).
  • Figure 5: The polarization profiles for the brightest pulse detected by FAST on July 25, 2024. The total intensity, the linear polarization, and circular polarization profiles are given by the solid line, dashed line and dotted line in the bottom sub-panel. The polarization angles are shown in the upper sub-panel.