Related papers: Pulsar emission amplified and resolved by plasma l…
We report on XMM-Newton observations of the Black Widow pulsar, PSR B1957+20. The pulsar's X-ray emission is non-thermal and best modeled with a single powerlaw spectrum of photon index 2.03^{+0.51}_{-0.36}. No coherent X-ray pulsations at…
Refractive interstellar scintillation (RISS) is thought to be the cause behind a variety of phenomena seen at radio wavelengths in pulsars and compact radio sources. Though there is substantial observational data to support several…
We compare signal and noise for observations of the scintillating pulsar B0834+06, using very-long baseline interferometry and a single-dish spectrometer. Comparisons between instruments and with models suggest that amplitude variations of…
Radio emission from pulsars can be used to map out their distances through dispersion measure (DM), which quantifies the amount of radio pulse dispersion. However, this method relies on accurately modelling the free electron density in the…
We describe the first X-ray observations of binary millisecond pulsars PSRs J0023+0923, J1810+1744, J2215+5135, and J2256-1024. All four are Fermi gamma-ray sources and three are 'black-widow' pulsars, with companions of mass < 0.1 solar…
In this paper, we report our investigation of pulsar scintillation phenomena by monitoring PSR B0355$+$54 at 2.25 GHz for three successive months using \emph{Kunming 40-m radio telescope}. We have measured the dynamic spectrum, the…
This thesis focuses on the study of binary radio pulsars, their evolution and some specific use of their properties to investigate fundamental physics such as general relativity and other gravitational theories. The work that we present…
We argue that eclipses of radio emission from the millisecond pulsar A in the double pulsar system J0737-3039 are due to synchrotron absorption by plasma in the closed field line region of the magnetosphere of its normal pulsar companion B.…
Scintillation of compact radio sources results from the interference between images caused by multipath propagation, and probes the intervening scattering plasma and the velocities of the emitting source and scattering screen. In…
Context. Interstellar scintillation (ISS) of pulsar emission can be used both as a probe of the ionised interstellar medium (IISM) and cause corruptions in pulsar timing experiments. Of particular interest are so-called scintillation arcs…
Interstellar scintillation analysis of pulsars allows us to probe the small-scale distribution and inhomogeneities of the ionized interstellar medium. Our priority is to present the data set and the basic measurements of scintillation…
Pulsar dynamic spectra exhibit high visibility fringes arising from interference between scattered radio waves. These fringes may be random or highly ordered patterns, depending on the nature of the scattering or refraction. Here we…
We report on the substructure of visibility functions in the delay domain of PSRs B0329+54, B0823+26, B0834+06, B1933+16 and B0833-45 (Vela) observed with earth-earth and RadioAstron space-earth two-element interferometers at frequencies of…
We have observed the relativistic binary pulsar PSR J1141$-$6545 over a period of $\sim$6 years using the Parkes 64 m radio telescope, with a focus on modelling the diffractive intensity scintillations to improve the accuracy of the…
This paper considers scattering screens that have arbitrary spatial variations of scattering strength transverse to the line of sight, including screens that are spatially well confined, such as disks and filaments. We calculate the…
Turbulence in the Local Bubble could play an important role in the thermodynamics of the gas that is there. The best astronomical technique for measuring turbulence in astrophysical plasmas is radio scintillation. Measurements of the level…
Since pulsars were discovered as emitters of bright coherent radio emission more than half a century ago, the cause of the emission has remained a mystery. In this Letter we demonstrate that coherent radiation can be directly generated in…
When the radio photons propagate through a non-uniform electron density volume, the plasma lensing effect can induce an extreme magnification to the observed flux at certain frequencies. Because the plasma lens acts as a diverging lens, it…
The features of pulsed $\gamma$-ray emission from classical and millisecond pulsars indicate that the high energy radiation processes in their inner magnetospheres occur in a similar way. In the last decade several TeV $\gamma$-ray nebulae…
We use VLBA+VLA observations to measure the sizes of the scatter-broadened images of 6 of the most heavily scattered known pulsars: 3 within the Galactic Centre (GC) and 3 elsewhere in the inner Galactic plane. By combining the measured…