Related papers: Pulsar Parallaxes at 5 GHz with the Very Long Base…
Determination of pulsar parallaxes and proper motions addresses fundamental astrophysical questions. We have recently finished a VLBI astrometry project to determine the proper motions and parallaxes of 27 pulsars, thereby doubling the…
The Vela pulsar is the brightest pulsar at radio wavelengths. It was the object that told us (via its glitching) that pulsars were solid rotating bodies not oscillating ones. Along with the Crab pulsar is it the source of many of the models…
Pulsar's position, proper motion and parallax are important parameters in timing equations. It is a really challenging work to fit astrometric parameters accurately through pulsar timing, especially for pulsars that show irregular timing…
The following results of dissertation are submitted for defense: 1. Precise measurements of coordinates and proper motion of the pulsar PSR 0329+54 using the VLBI method. 2. Establishing of the reason for the discrepancy between the…
We present the first results from a programme of multi-frequency simultaneous single pulse observations carried out as part of the European Pulsar Network. We detail the main data analysis methods and apply them to simultaneous observations…
(Abridged) This thesis describes the development of DiFX, the first general-purpose software correlator for radio interferometry, and its use with the Australian Long Baseline Array (LBA) to complete the largest VLBI pulsar astrometry…
On the Large Phased Array (LPA) of Lebedev Physics Institute (LPI), a search for pulsars outside the Galaxy plane was carried out in a 300 sq. deg area. The search with a sensitivity 5-10 times better than that of previously conducted…
Until now it has not been possible to obtain the proper motions of PSR B1849+00 with timing techniques or VLBI imaging given the enhanced interstellar scattering along its line of sight. We present an analysis of archive Very Large Array…
We present astrometric results on two millisecond pulsars, PSR B1257+12 and PSR J1022+1001, as carried out through VLBI. For PSR B1257+12, a model-independent distance of $710_{\rm -38}^{\rm +43}$ pc and proper motion of ($\mu_{\rm…
With unparalleled rotational stability, millisecond pulsars (MSPs) serve as ideal laboratories for numerous astrophysical studies, many of which require precise knowledge of the distance and/or velocity of the MSP. Here, we present the…
We present results from 3.6 cm observations of the quasar pair 1038+528 A and B, made in 1995 using the VLBA together with the Effelsberg 100m telescope. We describe the use of a phase-referencing technique to measure the astrometric…
Emission from the 6.7 GHz methanol maser transition is very strong, is relatively stable, has small internal motions, and is observed toward numerous massive star-forming regions in the Galaxy. Our goal is to perform high-precision…
We present proper motions obtained from a dual frequency, six-epoch, VLBA polarization experiment monitoring a sample of 12 blazars. The observations were made at 15 GHz and 22 GHz at bi-monthly intervals over 1996. Ten of the eleven…
Using the recently upgraded Long Baseline Array, we have measured the trigonometric parallax of PSR J0437-4715 to better than 1% precision, the most precise pulsar distance determination made to date. Comparing this VLBI distance…
We describe a data reduction pipeline for VLBI astrometric observations of pulsars, implemented using the ParselTongue AIPS interface. The pipeline performs calibration (including ionosphere modeling), phase referencing with proper…
We have timed four millisecond pulses, PSRs J1721-2457, J1745-0952, J1810-2005, and J1918-0642, for up to a total of 10.5 years each using multiple telescopes in the European Pulsar Timing Array network: the Westerbork Synthesis Radio…
The distance to the Vela pulsar (PSR B0833-45) has been traditionally assumed to be 500 pc. Although affected by a significant uncertainty, this value stuck to both the pulsar and the SNR. In an effort to obtain a model free distance…
The recently discovered transitional millisecond pulsar system J1023+0038 exposes a crucial evolutionary phase of recycled neutron stars for multiwavelength study. The system, comprising the neutron star itself, its stellar companion, and…
Parallax measurements of pulsars allow for accurate measurements of the interstellar electron density and contribute to accurate tests of general relativity using binary systems. The Square Kilometre Array (SKA) will be an ideal instrument…
PSR J1012+5307, a millisecond pulsar in orbit with a helium white dwarf (WD), has been timed with high precision for about 25 years. One of the main objectives of this long-term timing is to use the large asymmetry in gravitational binding…