scholarly journals Single Pulses and the Plasma-physical Processes of Pulsar Radio Emission

2017 ◽  
Vol 13 (S337) ◽  
pp. 73-78
Author(s):  
Joanna M. Rankin
Keyword(s):  
Radio Emission ◽  
Pulse Sequences ◽  
Single Pulse ◽  
Physical Processes ◽  
Pulsar Emission ◽  
Pulsar Radio ◽  
Cone Model ◽  
Chart Recorder ◽  
Polarization Characteristics ◽  
Pulsar Radio Emission

AbstractPulsars were discovered on the basis of their individual pulses, first by Jocelyn Bell and then by many others. This was chart-recorder science as computers were not yet in routine use. Single pulses carry direct information about the emission process as revealed in the detailed properties of their polarization characteristics. Early analyses of single pulses proved so dizzyingly complex that attention shifted to study of average profiles. This is turn led to models of pulsar emission beams—in particular the core/double-cone model—which now provides a foundation for understanding single-pulse sequences. We mention some of the 21stC single-pulse surveys and conclude with a brief discussion of our own recent analyses leading to the identification of the pulsar radio-emission mechanism of both slow and millsecond pulsars.

scholarly journals Characteristics of Pulsar Radio Emission at Single-pulse Resolution

2000 ◽  
Vol 177 ◽  
pp. 149-154
Author(s):  
Avinash A. Deshpande
Keyword(s):  
Radio Emission ◽  
Weighted Average ◽  
Single Pulse ◽  
Position Angle ◽  
Complex Nature ◽  
Stable States ◽  
Pulsar Radio ◽  
Emission Profile ◽  
Secondary State ◽  
Pulsar Radio Emission

Pulsar radio emission shows remarkably rich, but complex behavior in both intensity and polarization when considered on a pulse-to-pulse basis. A large number of pulses, when averaged together, tend to approach & define stable shapes that can be considered as distinct signatures of different pulsars. Such average profiles have shapes ranging from that describable as a simple one-component profile to those suggesting as many as 9 components. The components are understood as resulting from an average of many, often narrower, intities — the subpulses —that appear within the longitude range of a given component. The pulse components are thusformedand represent statistically an intensity-weighted average pattern of the radiation received as a function of longitude. The profile mode changes recognized in many pulsars suggest that the emission profile of a given pulsar may have two quasi-stable states, with one (primary) state more probable/brighter than the other (secondary) state. There are also (often associated) polarization modes that represent polarization states that are orthogonal to each other. The complex nature of orthogonaljumpsobserved in polarization position-angle sweeps may be attributable to possible superposition of two profile/polarization modes with orthogonal polarizations.

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 Observational Constraints on the Structure of the Pulsar Magnetic Field

1992 ◽  
Vol 128 ◽  
pp. 1-6
Author(s):  
A. D. Kuz'min
Keyword(s):  
Radio Emission ◽  
Plasma Frequency ◽  
Hollow Cone ◽  
Pulsar Radio ◽  
Cone Model ◽  
Curvature Radiation ◽  
Adopted Model ◽  
Magnetic Poles ◽  
Relativistic Particles ◽  
Pulsar Radio Emission

The most widely adopted model of pulsar radio emission is the hollow cone model, which fits much of the experimental data. The pulsar radio emission in this model is curvature radiation of relativistic particles flowing from the magnetic poles of the neutron star along a cone of open magnetic lines. The curvature radiation is amplified at the plasma frequency, therefore different radio frequencies f originate at different radii r of the emitting regions.

The Natural Wave Modes in a Pulsar Magnetosphere

1977 ◽  
Vol 3 (2) ◽  
pp. 120-122 ◽  
Author(s):  
D. B. Melrose ◽  
R. J. Stoneham
Keyword(s):  
Radio Emission ◽  
Pulsar Magnetosphere ◽  
Natural Wave ◽  
Pulsar Radio ◽  
Electron Positron ◽  
Polarization Characteristics ◽  
Pulsar Radio Emission ◽  
Wave Modes

Our purpose in this paper is to explore the properties of the natural wave modes of a relativistically streaming electron-positron gas and to apply the results to the interpretation of the polarization characteristics of pulsar radio emission.

scholarly journals Orthogonal Mode Polarization of Pulsar Radio Emission

2004 ◽  
Vol 218 ◽  
pp. 381-382
Author(s):  
Q. Luo ◽  
D. B. Melrose
Keyword(s):  
Numerical Simulation ◽  
Radio Emission ◽  
Circular Polarization ◽  
Single Pulse ◽  
Pulsar Radio ◽  
Natural Modes ◽  
Elliptically Polarized ◽  
Pulsar Radio Emission

We discuss a model for polarization of pulsar radio emission, based on the assumption that waves propagate in two elliptically polarized natural modes. Some results from numerical simulation of single pulses are discussed with emphasis on circular polarization, microstructures and single pulse statistics.

scholarly journals Pulsar emission at the bottom end of the electromagnetic spectrum

2012 ◽  
Vol 8 (S291) ◽  
pp. 317-320 ◽  
Author(s):  
Vladislav Kondratiev ◽  
Keyword(s):  
Low Frequency ◽  
Single Pulse ◽  
Spectral Width ◽  
Electromagnetic Spectrum ◽  
Fractional Bandwidth ◽  
Pulsar Emission ◽  
Pulsar Radio ◽  
Giant Pulses ◽  
Decameter Radio ◽  
Pulsar Radio Emission

AbstractPulsars are arguably the only astrophysical sources whose emission spans the entire electromagnetic spectrum, from decameter radio wavelengths to TeV energies. The LOw Frequency ARray (LOFAR) offers the unique possibility to study pulsars over a huge fractional bandwidth in the bottom 4 octaves of the radio window, from 15–240 MHz. Here we present a LOFAR study of pulsar single pulses, focussing specifically on the bright nearby pulsar B0809+74. We show that the spectral width of bright low-frequency pulses can be as narrow as 1 MHz and scales with increasing frequency as Δ f/fc ~ 0.15, at least in the case of the PSR B0809+74. This appears to be intrinsic to the pulsar, as opposed to being due to propagation effects. If so, this behavior is consistent with predictions by the strong plasma turbulence model of pulsar radio emission. We also present other observed properties of the single pulses and discuss their relation to other single-pulse phenomena like giant pulses.

scholarly journals Parameters of microstructure and noiselike intensity fluctuation in pulsar radio emission measured with submicrosecond time resolution provided by the S2 VLBI recording/playback system

2000 ◽  
Vol 177 ◽  
pp. 179-180 ◽  
Author(s):  
M.V. Popov ◽  
V.I. Kondrat’ev ◽  
V.I. Altunin ◽  
N. Bartel ◽  
W. Cannon ◽  
...  
Keyword(s):  
Radio Emission ◽  
Data Acquisition ◽  
Radio Telescope ◽  
Time Resolution ◽  
Intensity Fluctuation ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Pulsar Radio ◽  
Removal Technique ◽  
Pulsar Radio Emission

AbstractThree bright pulsars (B0950+08, B1133+16, and B1929+10) were observed with the 70-m radio telescope in Tidbinbilla at a frequency of 1650 MHz using the S2 Data Acquisition System which provided continuous recording of pulsar signals in two conjugate bands of B=16 MHz each. Parameters of microstructure have been analyzed using the predetection dispersion removal technique.

scholarly journals Evolution of Multipolar Magnetic Fields in Isolated Neutron Stars and its effect on Pulsar Radio Emission

2000 ◽  
Vol 177 ◽  
pp. 265-266
Author(s):  
D. Mitra ◽  
S. Konar ◽  
D. Bhattacharya ◽  
A. V. Hoensbroech ◽  
J. H. Seiradakis ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Radio Emission ◽  
Neutron Stars ◽  
Pulse Shape ◽  
Position Angle ◽  
Emission Region ◽  
Pulsar Radio ◽  
Significant Frequency ◽  
The Magnetic Field ◽  
Pulsar Radio Emission

AbstractThe evolution of the multipolar structure of the magnetic field of isolated neutron stars is studied assuming the currents to be confined to the crust. Lower orders (≤ 25) of multipole are seen to evolve in a manner similar to the dipole suggesting little or no evolution of the expected pulse shape. We also study the multifrequency polarization position angle traverse of PSR B0329+54 and find a significant frequency dependence above 2.7 GHz. We interpret this as an evidence of strong multipolar magnetic field present in the radio emission region.

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