Work

Constraints on the Low-frequency Radio Emission of the Galactic Fast Radio Burst Source SGR 1935+2154

Year: 2026

Type: article

Abstract: We present a search for radio pulses from the Galactic magnetar SGR 1935+2154, a well-known source of fast radio bursts (FRBs), at ∼110 MHz using the Large Phased Array (LPA) of the Pushchino Radio Astronomy Observatory. Data from two active periods in 2020 (March–May and September–November, with ∼3.5 minutes of daily coverage) were analyzed with new methods tailored to both FRB-like single pulses and pulsar-like periodic signals. No significant FRB-like pulses were found. Using Monte Carlo simulations, 3 σ upper limits were derived for the burst rate: for a lognormal energy distribution the limit is ∼10 1.5 day −1 for a mean of average monochromatic isotropic luminosity L ν ,mean ∼ 1.3 × 10 29 erg s −1 Hz −1 and a natural log-space scatter of σ ∼ 0.85; while for a power-law distribution it is ∼10 1.8 day −1 for an index β ≲ 3.0 and a minimum average monochromatic isotropic luminosity L ν , min ≲ 0.7 × 10 25 erg s − 1 Hz − 1 . When folded at the known 3.24781628 s period of SGR 1935+2154, a weak pulse was noted (S/N < 3.16), but the significance is insufficient for a secure detection of the pulsar-like emission signal. A conservative upper limit on the average monochromatic isotropic luminosity of any possible periodic emission is 2.08 × 10 19 erg s −1 Hz −1 . Our results offer meaningful low-frequency upper limits on the burst rate of SGR 1935+2154, and hint at very faint pulsar-like radiation at meter wavelengths.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/aea8f6