No Pulsar Detected in Reprocessed Archival Parkes Observations of SNR 1987A

TL;DR

The paper investigates whether a radio pulsar resides in SNR 1987A by reprocessing six Parkes archival observations (2006–2019) of the remnant with both periodicity and single-pulse search methods. Using PRESTO for $0$ to $1000$ pc cm$^{-3}$ dedispersed data and HEIMDALL/FETCH for dispersed pulses, no convincing candidates were found, but flux density, fluence, and $L_{1400}$ limits were derived, with the best $L_{1400}$ limits approaching those of Crab-like pulsars ($L_{1400}$ values of 56, 32, and 25 mJy kpc$^{2}$). This implies a pulsar with similar radio luminosity to known young pulsars cannot be ruled out. The study highlights the value of archival data reprocessing and informs future SKA-era searches, while noting that the remnant’s transparency at lower frequencies and potential plasma cutoff around $ sim 33$ GHz may affect detectability.

Abstract

We have reprocessed the available archival radio pulsar search observations of SNR 1987A taken with the Parkes 64-m telescope, some of which have not been previously published. We conducted a standard periodicity search on these data as well as a single pulse search at a range of dispersion measures. We found no convincing candidate signals, and we calculate flux density, luminosity, and single pulse fluence limits from these observations. The derived luminosity limits are comparable to the luminosities of three young, energetic pulsars (the Crab pulsar, PSR B0540$-$69, and PSR J0537$-$6910), and so we cannot rule out the existence of a pulsar in SNR 1987A with a similar radio luminosity.