Related papers: On Frequency-Dependent Dispersion Measures and Ext…
Fast radio bursts appear to exhibit large dispersion measures, typically exceeding any expected galactic interstellar contribution, especially along the moderate to high-galactic-latitude directions in which such events have been most often…
In an earlier paper (Ahuja, et al, 2005), based on simultaneous multi-frequency observations with the Giant Metrewave Radio Telescope (GMRT), we reported the variation of pulsar dispersion measures (DMs) with frequency. A few different…
We measure the effects of interstellar scattering on average pulse profiles from 13 radio pulsars with simple pulse shapes. We use data from the LOFAR High Band Antennas, at frequencies between 110 and 190~MHz. We apply a forward fitting…
The Parkes telescope has been monitoring 286 radio pulsars approximately monthly since 2007 at an observing frequency of 1.4 GHz. The wide dispersion measure (DM) range of the pulsar sample and the uniformity of the observing procedure make…
Compact radio sources such as pulsars and FRBs undergo scintillation in the interstellar medium (ISM) when scattered images interfere at the observer. ``Scintillometry'' refers to the range of techniques to extract astrometric information…
In our previous paper (Popov et al. (2016)) we investigated properties of the ionized interstellar medium in the direction of three distant pulsars: B1641-45, B1749-28, and B1933+16. We found that uniformly distributed scattering material…
Fast radio bursts (FRBs) are millisecond-timescale radio transients, the origins of which are predominantly extragalactic and likely involve highly magnetized compact objects. FRBs undergo multipath propagation, or scattering, from electron…
We analyze plasma dispersion and scattering of fast radio bursts (FRBs) to identify the dominant locations of free electrons along their lines of sight and thus constrain the distances of the burst sources themselves. We establish the…
Extreme scattering events (ESEs) are observed as dramatic ($>50\%$) drops in flux density that occur over an extended period of weeks to months. Discrete plasma lensing structures are theorized to scatter the radio waves produced by distant…
Modern radio interferometers sensitive to low frequencies will make use of wide-band detectors. For such wide bandwidths, dispersive atmospheric effects introduce variations in the fringe delay which change through the band of the…
We show that surface waves along interstellar current sheets closely aligned with the line of sight lead to pulsar scintillation properties consistent with those observed. This mechanism naturally produces the length and density scales of…
Gravitational microlensing has become a mature technique for discovering small gravitational lenses in the Universe which are otherwise beyond our detection limits. Similarly, plasma microlensing can help us explore cosmic plasma lenses.…
Conventional techniques that measure rapid time variations are inefficient or inadequate to discover and observe rapidly pulsating astronomical sources. It is therefore conceivable that there exist some classes of objects pulsating with…
We present a robust approach to incorporating models for the time-variable broadening of the pulse profile due to scattering in the ionized interstellar medium into profile-domain pulsar timing analysis. We use this approach to…
The turbulent ionized interstellar medium diffracts radio waves and makes them propagate in multiple paths. The pulse-broadening observed at low frequencies results from the scattering effect of interstellar clouds of ionized gas. During…
Radio pulsars scintillate because their emission travels through the ionized interstellar medium via multiple paths, which interfere with each other. It has long been realized that the scattering screens responsible for the scintillation…
We have searched for discrete refractive scattering events (including effects due to possible non-multiple diffractive scattering) at meter wavelengths in the direction of two close by pulsars B0950+08 and B1929+10, where we looked for…
Light travel time changes due to gravitational waves may be detected within the next decade through precision timing of millisecond pulsars. Removal of frequency-dependent interstellar medium (ISM) delays due to dispersion and scattering is…
The circumgalactic medium (CGM) is poorly constrained at the sub-parsec scales relevant to turbulent energy dissipation and regulation of multi-phase structure. Fast radio bursts (FRBs) are sensitive to small-scale plasma density…
We present an analysis of the variations seen in the dispersion measures (DMs) of 20 millisecond pulsars observed as part of the Parkes Pulsar Timing Array project. We carry out a statistically rigorous structure function analysis for each…