Related papers: Radio timing in a millisecond pulsar-extreme/inter…
The S-star cluster in the Galactic center allows us to study the physics close to a supermassive black hole, including distinctive dynamical tests of general relativity. Our best estimates for the mass of and the distance to Sgr A* using…
Binary pulsars provide an excellent system for testing general relativity because of their intrinsic rotational stability and the precision with which radio observations can be used to determine their orbital dynamics. Measurements of the…
A low-frequency gravitational-wave background (GWB) from the cosmic merger history of supermassive black holes is expected to be detected in the next few years by pulsar timing arrays. A GWB induces distinctive correlations in the pulsar…
We summarize the state of the art and future directions in using millisecond radio pulsars to test gravitation and measure intrinsic, fundamental parameters of the pulsar systems. As discussed below, such measurements continue to yield…
We report on the discovery of four millisecond pulsars (MSPs) in the High Time Resolution Universe (HTRU) pulsar survey being conducted at the Parkes 64-m radio telescope. All four MSPs are in binary systems and are likely to have white…
Ultra-light dark matter perturbs the orbital motion of binary pulsars, in particular by causing peculiar time variations of a binary's orbital parameters, which then induce variations in the pulses' times-of-arrival. Binary pulsars have…
Pulsars orbiting the Galactic center black hole, Sgr A*, would be potential probes of its mass, distance and spin, and may even be used to test general relativity. Despite predictions of large populations of both ordinary and millisecond…
We report results from continued timing observations of PSR J0740+6620, a high-mass, 2.8-ms radio pulsar in orbit with a likely ultra-cool white dwarf companion. Our data set consists of combined pulse arrival-time measurements made with…
Pulsars are remarkably precise "celestial clocks" that can be used to explore many different aspects of physics and astrophysics. In this article I give a brief summary of pulsar properties and describe some of the applications of pulsar…
The S stars near the Galactic centre and any pulsars that may be on similar orbits, can be modelled in a unified way as clocks orbiting a black hole, and hence are potential probes of relativistic effects, including black hole spin. The…
An outstanding question in modern Physics is whether general relativity (GR) is a complete description of gravity among bodies at macroscopic scales. Currently, the best experiments supporting this hypothesis are based on high-precision…
The measurement of the Shapiro time delay in binary pulsar systems with highly inclined orbit can be affected both by the motion of the pulsar's companion because of the finite time it takes a photon to cross the binary, and by the…
The motivation for radio pulsar timing and its basic principles are reviewed. Present and future radio timing techniques and hardware are summarised and compared. The array of present timing programmes and their scientific goals are…
Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems will modulate the arrival times of pulses from…
We discuss the observable effects of enhanced black-hole mass loss in a black hole--neutron star (BH--NS) binary, due to the presence of a warped extra spatial dimension of curvature radius $L$ in the braneworld scenario. For some masses…
The aim of this paper is to study the time delay on electromagnetic signals propagating across a binary stellar system. We focus on the antisymmetric gravitomagnetic contribution due to the angular momentum of one of the stars of the pair.…
A new method of polarimetric calibration is presented in which the instrumental response is derived from regular observations of PSR J0437-4715 based on the assumption that the mean polarized emission from this millisecond pulsar remains…
Pulsar timing experiments are reaching sufficient sensitivity to detect a postulated stochastic gravitational wave background generated by merging supermassive black hole systems in the cores of galaxies. We describe the techniques behind…
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…
The pulsar timing residuals induced by gravitational waves from non-evolving single binary sources are affected by many parameters related to the relative positions of the pulsar and the gravitational wave sources. We will fully analyze the…