Observations of Giant Pulses From Pulsar B0950+08 Using Lwa1

Abstract

We report the detection of giant pulse emission from PSR B0950+08 in 24 hours of observations made at 39.4 MHz, with a bandwidth of 16 MHz, using the first station of the Long Wavelength Array, LWA1. We detected 119 giant pulses from PSR B0950+08 (at its dispersion measure), which we define as having SNRs at least 10 times larger than for the mean pulse in our data set. These 119 pulses are 0.035% of the total number of pulse periods in the 24 hours of observations. The rate of giant pulses is about 5.0 per hour. The cumulative distribution of pulse strength S is a steep power law, N (> S) ∝ S −4.7 , but much less steep than would be expected if we were observing the tail of a Gaussian distribution of normal pulses. We detected no other transient pulses in a dispersion measure range from 1 to 90 pc cm −3 , in the beam tracking PSR B0950+08. The giant pulses have a narrower temporal width than the mean pulse (17.8 ms, on average, vs. 30.5 ms). The pulse widths are consistent with a previously observed weak dependence on observing frequency, which may be indicative of a deviation from a Kolmogorov spectrum of electron density irregularities along the line of sight. The rate and strength of these giant pulses is less than has been observed at ∼100 MHz. Additionally, the mean (normal) pulse flux density we observed is less than at ∼100 MHz. These results suggest this pulsar is weaker and produces less frequent giant pulses at 39 MHz than at 100 MHz.for gravitational-wave events, triggered by the detection of radio transients. The benefits of such collaborative work will be described in another publication.We would like to acknowledge insightful discussions with S.W. Ellingson, T.J.W. Lazio and P. S. Ray.

SIMULTANEOUS OBSERVATIONS OF GIANT PULSES FROM PULSAR PSR B0950+08 AT 42 AND 74 MHz

“…Another common property of GPs is that they exhibit a non-Gaussian power-law distribution in the peak flux density. GP observations of PSR B0950+08 over the frequency range 39-111 MHz indicate further that the rate and strength of GP emission is reduced at ∼39 MHz as compared to ∼100 MHz (Singal & Vats 2012;Smirnova 2012;Tsai et al 2015). In this paper we extend the previous study of PSR B0950+08 by Tsai et al (2015) with simultaneous observations at two frequencies of 42 and 74 MHz.…”

“…The most commonly discussed power law is for a Kolmogorov spectrum. Our previous observations of PSR B0950+08 suggested that the spectrum along this line-of-sight deviates from Kolmogorov (Tsai et al 2015). In this work, we explore this issue further by considering the effect of scattering on the GPs and APs simultaneous observed at two frequencies.…”

A search for pulsars in subdwarf B binary systems and discovery of giant-pulse emitting PSR J0533−4524

“…The giant pulses have widths between 2.5 and 10.0 ms, which is 10 − 30% of the width of the integrated profile. These widths are a similar fraction of the mean pulse as the giant pulses observed in PSR B0950+08 Tsai et al (2015). Together with the narrow phase window centred on one component of the integrated profile, this supports that the single pulses are indeed giant pulses.…”

Time-domain and spectral properties of pulsars at 154 MHz

“…A small subset of pulsars are known to emit giant radio pulses (e.g. Johnston et al 2001, Tsai et al 2015. Giant pulses are typically broadband in nature with a low duty cycle when compared with normal pulses (see Lorimer & Kramer 2012;Oronsaye et al 2015).…”