scholarly journals Spectral Flattening of Crab Giant Pulses at Low Frequencies

2017 ◽  
Vol 13 (S337) ◽  
pp. 378-379
Author(s):  
Bradley W. Meyers ◽  
Steven E. Tremblay ◽  
N. D. Ramesh Bhat ◽  
Ryan M. Shannon
Keyword(s):  
Crab Pulsar ◽  
Giant Pulse ◽  
Pulse Emission ◽  
Low Frequencies ◽  
Pulsar Radio ◽  
Giant Pulses ◽  
Spectral Behaviour ◽  
The Mean ◽  
Murchison Widefield Array ◽  
Pulsar Radio Emission

AbstractThe frequency dependence of normal pulsar radio emission is typically observed to be a power law, with some indications of a flattening or turnover at low frequencies (≲ 100 MHz). The spectrum of the Crab pulsar’s giant pulse emission has not been examined as closely. We conducted simultaneous wideband observations of the Crab pulsar, with the Parkes radio telescope and the Murchison Widefield Array, to study the spectral behaviour of its giant pulses. Our analysis shows that the mean spectral index of Crab giant pulses flattens at low frequencies, from −2.6 ± 0.5 between the Parkes bands, to −0.7 ± 1.4 between the lowest MWA subbands.

scholarly journals Search for a Correlation Between Radio Giant Pulses and VHE Photons of the Crab Pulsar

10.14311/1472 ◽  
2011 ◽  
Vol 51 (6) ◽  
Author(s):  
N. Lewandowska ◽  
D. Elsäesser ◽  
K. Mannheim
Keyword(s):  
Radio Emission ◽  
Special Form ◽  
Electromagnetic Spectrum ◽  
Crab Pulsar ◽  
Pulsar Emission ◽  
Pulsar Radio ◽  
Giant Pulses ◽  
Pulse Structure ◽  
Unique Source ◽  
Pulsar Radio Emission

The Crab pulsar is a unique source of pulsar radio emission. Its regular pulse structure is visible over the entire electromagnetic spectrum from radio to GeV ranges. Among the regular pulses, radio giant pulses (GPs) are known as a special form of pulsar radio emission. Although the Crab pulsar was discovered by its GPs, their origin and emission mechanisms are currently not understood. Within the framework of this report we give a review on radio GPs and present a new idea on how to examine the characteristics of this as yet not understood kind of pulsar emission.

scholarly journals Super-giant pulses from the Crab pulsar: energy distribution and occurrence rate

2019 ◽  
Vol 490 (1) ◽  
pp. L12-L16 ◽  
Author(s):  
Apurba Bera ◽  
Jayaram N Chengalur
Keyword(s):  
Energy Distribution ◽  
Power Law ◽  
Pulse Energy ◽  
Occurrence Rate ◽  
Crab Pulsar ◽  
Limited Sample ◽  
Pulse Emission ◽  
High Fluences ◽  
Giant Pulses ◽  
Power Law Index

ABSTRACT We present statistical analysis of a fluence-limited sample of over 1100 giant pulses from the Crab pulsar, with fluence > 130 Jy ms at ∼1330 MHz. These were detected in ∼260 h of observation with the National Centre for Radio Astrophysics (NCRA) 15 m radio telescope. We find that the pulse-energy distribution follows a power law with index $\rm \alpha \approx -3$ at least up to a fluence of ∼5 Jy s. The power-law index agrees well with that found for lower-energy pulses in the range 3–30 Jy ms. The fluence distribution of the Crab pulsar hence appears to follow a single power law over ∼3 orders of magnitude in fluence. We do not see any evidence for the flattening at high fluences reported by earlier studies. We also find that, at these fluence levels, the rate of giant-pulse emission varies by as much as a factor of ∼5 on time-scales of a few days, although the power-law index of the pulse-energy distribution remains unchanged. The slope of the fluence distribution for Crab giant pulses is similar to that recently determined for the repeating FRB 121102. We also find an anti-correlation between the pulse fluence and the pulse width, so that more energetic pulses are preferentially shorter.

scholarly journals STATISTICAL STUDIES OF GIANT PULSE EMISSION FROM THE CRAB PULSAR

2011 ◽  
Vol 741 (1) ◽  
pp. 53 ◽  
Author(s):  
Walid A. Majid ◽  
Charles J. Naudet ◽  
Stephen T. Lowe ◽  
Thomas B. H. Kuiper
Keyword(s):  
Crab Pulsar ◽  
Giant Pulse ◽  
Pulse Emission ◽  
Statistical Studies

scholarly journals Giant Pulses — A Brief Review

2004 ◽  
Vol 218 ◽  
pp. 315-318
Author(s):  
Simon Johnston ◽  
Roger W. Romani
Keyword(s):  
Power Law ◽  
High Energy ◽  
Giant Pulse ◽  
Pulse Emission ◽  
Energy Emission ◽  
Giant Pulses ◽  
Definition Of ◽  
High Energy Emission

We briefly review observational manifestations of pulsars with giant pulse emission and consider quasi-giant pulse phenomena in other pulsars. We argue that power-law statistics give the best definition of giant pulses. Finally, we speculate as to the origin of the giant pulses and a possible link with high energy emission.

scholarly journals LOFAR radio search for single and periodic pulses from M 31

2020 ◽  
Vol 634 ◽  
pp. A3 ◽  
Author(s):  
Joeri van Leeuwen ◽  
Klim Mikhailov ◽  
Evan Keane ◽  
Thijs Coenen ◽  
Liam Connor ◽  
...  
Keyword(s):  
Low Frequency ◽  
Crab Pulsar ◽  
Radio Bursts ◽  
Pulse Emission ◽  
Giant Pulses ◽  
Wide Range ◽  
The Galaxy ◽  
Order Of Magnitude ◽  
M 31 ◽  
Pulsar Populations

Bright short radio bursts are emitted by sources at a wide range of distances: from the nearby Crab pulsar to remote fast radio bursts (FRBs). FRBs are likely to originate from distant neutron stars, but our knowledge of the radio pulsar population has been limited to the Galaxy and the Magellanic Clouds. In an attempt to increase our understanding of extragalactic pulsar populations and their giant-pulse emission, we employed the low-frequency radio telescope LOFAR to search the Andromeda galaxy (M 31) for radio bursts emitted by young Crab-like pulsars. For direct comparison we also present a LOFAR study on the low-frequency giant pulses from the Crab pulsar; their fluence distribution follows a power law with slope 3.04 ± 0.03. A number of candidate signals were detected from M 31, but none proved persistent. FRBs are sometimes thought of as Crab-like pulsars with exceedingly bright giant pulses; based on our sensitivity, we can rule out that M 31 hosts pulsars that are more than an order of magnitude brighter than the Crab pulsar if their pulse scattering follows that of the known FRBs.

scholarly journals Observations of Giant Pulses from Pulsar PSR B1937+21

1996 ◽  
Vol 160 ◽  
pp. 209
Author(s):  
S. E. Thorsett ◽  
J. A. Shrauner ◽  
I. Cognard ◽  
J. H. Taylor
Keyword(s):  
Power Law ◽  
Millisecond Pulsar ◽  
Power Law Distribution ◽  
Sampling System ◽  
Giant Pulse ◽  
Circularly Polarized ◽  
Giant Pulses ◽  
Interstellar Scattering ◽  
The Mean ◽  
The Individual

AbstractWe discuss observations of giant pulses from the millisecond pulsar PSR B1937+21 at 430 MHz, with a baseband sampling system at Arecibo (Shrauner et al., these proceedings) and coherent dedispersion techniques. About one pulse or interpulse per hundred thousand is stronger than 100 times the mean flux density, and the giant pulse strengths follow a power law distribution somewhat shallower than that of the Crab giant pulses. The individual giant pulses appear consistent with impulses shorter than a few microseconds, convolved with an exponential due to interstellar scattering. They are systematically delayed with respect to the average emission, and many are nearly 100% circularly polarized.

scholarly journals Are Giant Pulses Evidence of Self-Organized Criticality?

1996 ◽  
Vol 160 ◽  
pp. 179-180 ◽  
Author(s):  
Matthew D. T. Young ◽  
Brian G. Kenny
Keyword(s):  
Power Laws ◽  
Crab Pulsar ◽  
Statistical Distributions ◽  
Millisecond Pulsar ◽  
Recent Discussion ◽  
Scale Invariant ◽  
Giant Pulse ◽  
Self Organized ◽  
Giant Pulses ◽  
Self Organized Criticality

The statistical distributions of certain giant pulse (GP) properties appear to be well described by power laws. This suggests that the emission mechanism that produces giant pulses is a scale-invariant one. In turn this may indicate that the source of the GPs is in a state of self-organized criticality (SOC). For a recent discussion of SOC see Sornetteet al. (1995).Prior to this conference, the only pulsars reported to exhibit GPs were the Crab pulsar, PSR B0531+21 (Lundgrenet al. 1995), and the millisecond pulsar PSR B1937+21 (Cognardet al. 1996). However, at the conference it was reported that giantmicropulseshad recently been observed from PSR J0437–4715 (Ables and McConnell, this volume). In all cases the statistical distributions of observed GP heights and/or fluxes are found to be well described by simple power laws. The arguments in this note apply to all these pulsars.

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