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 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.

scholarly journals Polarization in Pulsar Radio Emission

1992 ◽  
Vol 128 ◽  
pp. 384-386
Author(s):  
D. M. GOULD
Keyword(s):  
Radio Emission ◽  
Circular Polarization ◽  
Linear Polarization ◽  
Large Data ◽  
Position Angle ◽  
Published Data ◽  
Data Set ◽  
Pulsar Radio ◽  
Polarization Profiles ◽  
Pulsar Radio Emission

Polarimetric observations of over 300 pulsars have been carried out between 21 December 1988 and 22 January 1990 at 606, 610, 925, and 1408 MHz using the Lovell Telescope at Jodrell Bank. Many of these pulsars have no previously published polarization profiles and will be published shortly (Gould and Lyne 1990). This large data set along with previously published data from various sources, has been used to test the correlation found by Radhakrishnan and Rankin (1990) between sense reversing circular polarization signatures and the accompanying sense of rotation of the linear polarization position angle.

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 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 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.

Orthogonal Polarization in Pulsar Radio Emission

1975 ◽  
Vol 2 (6) ◽  
pp. 334-336 ◽  
Author(s):  
R.N. Manchester
Keyword(s):  
Source Region ◽  
Position Angle ◽  
Orthogonal Polarization ◽  
Magnetic Pole ◽  
Pulse Profile ◽  
Pulsar Radio ◽  
Emission Process ◽  
Integrated Or ◽  
Pulsar Radio Emission ◽  
Different Parts

For many pulsars the integrated or mean pulse profile is highly polarized. Generally linear polarization dominates over circular and there is a continuous variation of position angle through the profile (e.g. Manchester 1971). In most models for the emission process the angle of polarization is related to the (projected) direction of magnetic fields in the source region. Several of the observed properties of pulsars, for example, the mode-changing phenomenon (Backer 1970) and the different spectral index of different components of the intergrated profile (Manchester 1971), suggest that different parts of the integrated profile are emitted in different (though closely related) parts of the source. The different observed position angles across the integrated profile would then result from different projected magnetic field directions in these different parts of the source. For many pulsars the observed position angle variations are closely represented by a path through a radial set of projected field directions such as would be obtained in the vicinity of a magnetic pole (cf. Radhakrishnan and Cooke 1969).

scholarly journals Organised polarisation variability in radio pulsars and consequences for emission theory

2017 ◽  
Vol 13 (S337) ◽  
pp. 79-82
Author(s):  
Cristina-Diana Ilie ◽  
Patrick Weltevrede
Keyword(s):  
Radio Emission ◽  
Single Pulse ◽  
Position Angle ◽  
Emission Mechanism ◽  
Radio Pulsars ◽  
High Quality ◽  
Special Cases ◽  
High Quality Sample ◽  
Linear Polarisation ◽  
Periodic Switching

AbstractThe aim of this work is to explore the connection between variability in single pulse intensity and periodic switching of the position angle (PA) of the linear polarisation and how this relates to the radio emission mechanism. There are five pulsars reported in the literature for which the PA is seen to periodically change in tandem with the variability in their pulse shapes. This behaviour is seemingly incompatible with two well established models of the radio emission mechanism. The purpose of this study is to investigate in a systematic way whether this phenomenon is common or if only happens in special cases, using a high-quality sample of pulsar data observed with the Parkes telescope. We show that the connection between polarisation variability and intensity variability is more common than previously expected.

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