A5060915950- History and Developments in Astronomy
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Geophysics and Sensor Technology
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Space exploration and regulation
- Advanced Frequency and Time Standards
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Photonic and Optical Devices
- Inertial Sensor and Navigation
- Geomagnetism and Paleomagnetism Studies
- Historical Astronomy and Related Studies
- GNSS positioning and interference
- Vietnamese History and Culture Studies
- High-pressure geophysics and materials
- Particle accelerators and beam dynamics
- Scientific Research and Discoveries
University of Rochester
2018-2020
University of Manchester
1992-2012
SKA Observatory
1987-2012
Royal Observatory in Greenwich
1977-1982
Cavendish Hospital
1948-1982
National Radio Astronomy Observatory
1982
Union astronomique internationale
1982
Business in the Community
1971
Government of Western Australia
1964
University of Cambridge
1959-1961
Between glitches, the rotational slowdown of Crab pulsar is well described by a power law with braking index 2.51 ± 0.01. Six glitches occurred during period from 1969 to 1993; largest, in 1989, while observations were progress and was observed unprecedented detail. The discontinuous changes rotation at each glitch include components whose effect decays over periods between 1 about 200 d; main effect, however, an increase rate time glitch. This persistent cumulative, contributing overall...
Shemar & Lyne have previously presented observations and an analysis of 32 glitches their subsequent relaxations observed in a total 15 pulsars. These data are brought together this paper with those published by other authors. We show quantitatively how glitch activity decreases linearly decreasing rate slow-down. As indicated from studies the Vela pulsar, suggests that 1.7 per cent moment inertia typical neutron star is normally contained pinned superfluid which releases its excess angular...
As the author says, there exists a vast literature of general works on electricity and magnetism. This book extracts organizes topics most relevant to radiation theory, presents them student who is equipped with basic physical facts mathematical techniques, but may need some guidance through morass analysis found in more exhaustive works.
We present observations of the arrival times pulses from pulsar in Crab Nebula over a six-year interval. The data are intended to permit investigation interior neutron star through study glitches and timing noise provide an ephemeris for high-energy observations. first second frequency derivatives value braking index |$n=2.509\pm0.001$|, which is consistent with previous third derivative can now be determined 18-yr span as expected this index. predominant deviations simple slow-down model...
The shape and structure of radio pulses from the majority pulsars have been studied at frequencies 151, 240, 408 610 MHz, using polarimeter receivers. Individual stronger recorded photographically. integrated pulse profiles obtained on-line integration four Stokes parameters. Many results are presented graphically; main characteristics collected in a table. A discussion widths change polarization angle within supports view that profile represents longitude distribution emission, while...
A number of new methods using spaced aerial interferometers to determine the position a radio star have been devised, and their accuracies are here compared with those which already used. The particularly applicable accurate determination positions small most intense stars. apparent as determined by all such will differ from true because various refraction effects in Earth's atmosphere; magnitude these at wave-lengths is estimated this paper. It shown that results may be confused...
The rotation measures and dispersion of 185 pulsars are used to delineate the galactic magnetic field. nearer pulsars, with measure DM < 40 pc cm−3, indicate that local field is about 2–3 μG, directed toward l=90°. more distant at smaller galactocentric distances reversed stronger. comparatively low extragalactic sources in other directions, including direction anticenter, existence reversals.
The optical polarizations of the Crab Nebula Pulsar has been remeasured, using a new determination polarization background emission from nebula. pulsar at minimum light is 47±10 per cent polarized p.a. 130°. characteristics two pulse components are remarkably similar. observations support model in which and other high-energy radiation emitted close to cylinder, pulses corresponding magnetic poles nearly orthogonal rotator.
The period derivatives for 56 pulsars have been obtained from two sets of timing observations 1 yr apart. A total 84 are now known. Statistical relationships between period, derivative, magnetic field strength, luminosity, integrated pulse width and apparent age examined. distribution values derivative is explained by postulating a secular decay dipole moment. cut-off radio emission appears to be related the near velocity light cylinder.
The radio pulses from pulsars are formed by a beam of directed emission which sweeps across the observer. structure individual pulses, rather than average pulse shape, is considered to be important. could an anisotropic process, such as synchrotron radiation, or propagation, relativistic effect rapid orbital motion source. Pulse shapes expected radiation and calculated. Comparison with observed widths polarization suggests that they effect, mechanism through some process akin cyclotron radiation.