Related papers: A proposed signal discovery method in interstellar…
Impulsive radio-frequency signals from astronomical sources are dispersed by the frequency dependent index of refraction of the interstellar media and so appear as chirped signals when they reach earth. Searches for dispersed impulses have…
The investigation of the Earth ionosphere both in a quiet and a disturbed states is still desirable. Despite recent progress in its modeling and in estimating the electron concentration along the line of sight by GPS signals, the impact of…
We provide timing solutions for 45 radio pulsars discovered by the Robert C. Byrd Green Bank Telescope. These pulsars were found in the Green Bank North Celestial Cap pulsar survey, an all-GBT-sky survey being carried out at a frequency of…
In this paper, the performance of a binary phase shift keyed random time-hopping impulse radio system with pulse-based polarity randomization is analyzed. Transmission over frequency-selective channels is considered and the effects of…
A number of pulsar timing arrays have recently reported preliminary evidence for the existence of a nanohertz frequency gravitational-wave background. These analyses rely on detailed noise analyses, which are inherently complex due to the…
In order to show the principle viability of a recently proposed relativistic positioning method based on the use of pulsed signals from sources at infinity, we present an application example reconstructing the world-line of an idealized…
Stellar intensity interferometers correlate photons within their coherence time and could overcome the baseline limitations of existing amplitude interferometers. Intensity interferometers do not rely on phase coherence of the optical…
In this paper we present recent Low Frequency Array (LOFAR) observations of the pulsar J1740+1000. We confirm that its spectrum has a turnover at 260 MHz, which is unusual for a typical pulsar. We argue that in this case interferometric…
Pulsars, especially millisecond pulsars, are intrinsically very stable celestial clocks, and their great pulse period stability open up a wide range of potential applications to astronomical phenomena, such as a natural detector for very…
Radio polarimetry is a three-dimensional statistical problem. The three-dimensional aspect of the problem arises from the Stokes parameters Q, U, and V, which completely describe the polarization of electromagnetic radiation and…
Pulsar timing array projects measure the pulse arrival times of millisecond pulsars for the primary purpose of detecting nanohertz-frequency gravitational waves. The measurements include contributions from a number of astrophysical and…
Context. Studies on compact galaxy groups have led to the conclusion that a plenitude of phenomena take place in between galaxies that form them. However, radio data on these objects are extremely scarce and not much is known concerning the…
Using relative stellar astrometry for the detection of coherent gravitational wave sources is a promising method for the microhertz range, where no dedicated detectors currently exist. Compared to other gravitational wave detection…
A method for measuring the difference between centroids of polarized flux and total flux of an astronomical object - {\it polaroastrometry} - is proposed. The deviation of the centroid of flux corresponding to Stokes parameter $Q$ or $U$…
Ground based low frequency radio interferometers have been developed in the last decade and are providing the scientific community with high quality observations. Conversely, current radioastronomy instruments in space have a poor angular…
We report on the setup and initial discoveries of the Northern High Time Resolution Universe survey for pulsars and fast transients, the first major pulsar survey conducted with the 100-m Effelsberg radio telescope and the first in 20 years…
We use the precision measurements of the arrival time differences of the same fast radio burst (FRB) source along multiple sightlines to measure the primordial power spectrum and Non-Gaussianities. The anticipated experiment requires a…
Radio emission from pulsars is known to exhibit a diverse range of emission phenomena, among which nulling, where the emission becomes temporarily undetectable, is an intriguing one. Observations suggest nulling is prevalent in many…
This thesis work is focused on the study of millisecond pulsars in globular cluster by using multi-wavelength observations obtained with radio and optical telescopes. Radio observations have been used to search for and timing the pulsars.…
The International Pulsar Timing Array project combines observations of pulsars from both Northern and Southern hemisphere observatories with the main aim of detecting ultra-low frequency (~10^-9 to 10^-8 Hz) gravitational waves. Here we…