A5081228919- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Advanced Frequency and Time Standards
- Superconducting Materials and Applications
- Cosmology and Gravitation Theories
- Astrophysical Phenomena and Observations
- GNSS positioning and interference
- High-pressure geophysics and materials
- Geophysics and Sensor Technology
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Magnetic confinement fusion research
- Astronomy and Astrophysical Research
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Particle accelerators and beam dynamics
- Galaxies: Formation, Evolution, Phenomena
- Inertial Sensor and Navigation
- Computational Physics and Python Applications
- Superconducting and THz Device Technology
- Scientific Research and Discoveries
Australia Telescope National Facility
2016-2025
Commonwealth Scientific and Industrial Research Organisation
2016-2025
Astronomy Australia
2021-2025
Astronomy and Space
2015-2024
Chinese Academy of Sciences
2016-2021
Xinjiang Astronomical Observatory
2021
University of Chinese Academy of Sciences
2021
Australian Research Council
2020
Tata Institute of Fundamental Research
2020
National Astronomical Observatories
2016-2020
We have compiled a new and complete catalog of the main properties 1509 pulsars for which published information currently exists. The includes all spin-powered as well anomalous X-ray soft gamma-ray repeaters showing coherent pulsed emission, but excludes accretion-powered systems. References are given data listed. also developed web interface accessing displaying either tabular or plotted with option selecting to be displayed via logical conditions on parameter expressions. has an...
Contemporary pulsar-timing experiments have reached a sensitivity level where systematic errors introduced by existing analysis procedures are limiting the achievable science. We developed tempo2, new package that contains propagation and other relevant effects implemented at 1-ns of precision (a factor ∼100 more precise than previously obtainable). In contrast with earlier timing packages, tempo2 is compliant general relativistic framework IAU 1991 2000 resolutions hence uses International...
The double pulsar system PSR J0737-3039A/B is unique in that both neutron stars are detectable as radio pulsars. They also known to have much higher mean orbital velocities and accelerations than those of other binary therefore a good candidate for testing Einstein's theory general relativity alternative theories gravity the strong-field regime. We report on precision timing observations taken over 2.5 years since its discovery present four independent tests relativity. These use...
We present and analyse a catalogue of 233 pulsars with proper motion measurements. The sample contains wide variety including recycled objects those associated globular clusters or supernova remnants. After taking the most precise motions for which multiple measurements are available, majority (58%) derived from pulsar timing methods, 41% using interferometers remaining 1% optical telescopes. Many 1-D 2-D speeds (referring to measured in one coordinate only magnitudes transverse velocities...
Abstract Pulsar timing arrays aim to detect nanohertz-frequency gravitational waves (GWs). A background of GWs modulates pulsar arrival times and manifests as a stochastic process, common all pulsars, with signature spatial correlation. Here we describe search for an isotropic gravitational-wave (GWB) using observations 30 millisecond pulsars from the third data release Parkes Timing Array (PPTA), which spans 18 yr. Using current Bayesian inference techniques recover characterize...
The International Pulsar Timing Array project combines observations of pulsars from both northern and southern hemisphere observatories with the main aim detecting ultra-low frequency (∼ 10−9–10−8 Hz) gravitational waves. Here we introduce project, review methods used to search for waves emitted coalescing supermassive binary black-hole systems in centres merging galaxies discuss status project.
Tempo2 is a new software package for the analysis of pulsar pulse times arrival. In this paper we describe in detail timing model used by tempo2, and discuss limitations on attainable precision. addition to intrinsic slow-down behaviour pulsar, tempo2 accounts effects binary orbital motion, secular motion or system, interstellar, Solar system ionospheric dispersion, observatory (including Earth rotation, precession, nutation, polar motion), tropospheric propagation delay, gravitational time...
[ABRIDGED] We present the discovery and follow-up observations of 142 pulsars found in Parkes 20-cm multibeam pulsar survey Galactic plane. These new discoveries bring total number by to 742. In addition tabulating spin astrometric parameters, along with pulse width flux density information, we orbital characteristics for 13 binary which form part sample. Combining these results from another recent at high latitudes, have a sample 1008 normal use carry out determination their distribution...
Pulsars are famed for their rotational clock-like stability and highly-repeatable pulse shapes. However, it has long been known that there unexplained deviations (often termed "timing noise") from the rate at which we predict these clocks should run. We show timing behaviour often results typically two different spin-down rates. switch abruptly between states, quasi-periodically, leading to observed patterns. six pulsars noise is correlated with changes in shape. Many pulsar phenomena...
A "pulsar timing array" (PTA), in which observations of a large sample pulsars spread across the celestial sphere are combined, allows investigation "global" phenomena such as background gravitational waves or instabilities atomic timescales that produce correlated residuals array. The Parkes Pulsar Timing Array (PPTA) is an implementation PTA concept based on with 64-m radio telescope. 20 millisecond being observed at three radio-frequency bands, 50cm (~700 MHz), 20cm (~1400 MHz) and 10cm...
Placing bounds on gravitational wave detection Gravitational waves are expected to be generated by the interaction of massive bodies in black-hole binary systems. As distort spacetime, it should possible verify their existence as they interfere with pulses emitted millisecond pulsars. However, after monitoring 24 pulsars Parkes radio telescope for 12 years, Shannon et al. found no detectable variation pulsar records. This nondetection result indicates that a new strategy is needed. Science ,...
The highly stable spin of neutron stars can be exploited for a variety (astro)physical investigations. In particular, arrays pulsars with rotational periods the order milliseconds used to detect correlated signals such as those caused by gravitational waves. Three ‘pulsar timing arrays’ (PTAs) have been set up around world over past decades and collectively form ‘International’ PTA (IPTA). this paper, we describe first joint analysis data from three regional PTAs, i.e. IPTA set. We available...
We present pulsar timing solutions for 374 pulsars. Each ephemeris was obtained by analysing archival data stored at Jodrell Bank Observatory. This archive contains over 5600 yr of rotational history with individual data‐spans up to 34 yr. A new method has been developed mitigate the effects noise whitening residuals. is applied before standard fitting procedures are followed measure astrometric and dispersion (DM) parameters a pulsar. show that values using this technique consistent other...
On a time scale of years to decades, gravitational wave (GW) astronomy will become reality.Low frequency (∼10 -9 Hz) GWs are detectable through long-term timing observations the most stable pulsars.Radio observatories worldwide currently carrying out observing programmes detect GWs, with data sets being shared International Pulsar Timing Array project.One likely sources low supermassive black hole binaries (SMBHBs), as background due large number binaries, or continuous burst emission from...
We present timing models for 20 millisecond pulsars in the Parkes Pulsar Timing Array. The precision of parameter measurements these has been improved over earlier results by using longer data sets and modelling non-stationary noise. describe a new noise procedure demonstrate its effectiveness simulated data. Our methodology includes addition annual dispersion measure (DM) variations to some pulsars. first significant parallax PSRs J1024−0719, J1045−4509, J1600−3053, J1603−7202, J1730−2304,...
We searched for an isotropic stochastic gravitational wave background in the second data release of International Pulsar Timing Array, a global collaboration synthesizing decadal-length pulsar-timing campaigns North America, Europe, and Australia. In our reference search power law strain spectrum form $h_c = A(f/1\,\mathrm{yr}^{-1})^{\alpha}$, we found strong evidence spectrally-similar low-frequency process amplitude $A 3.8^{+6.3}_{-2.5}\times10^{-15}$ spectral index $\alpha -0.5 \pm 0.5$,...
In this paper, we describe the International Pulsar Timing Array second data release, which includes recent pulsar timing obtained by three regional consortia: European Array, North American Nanohertz Observatory for Gravitational Waves, and Parkes Array. We analyse where possible combine high-precision 65 millisecond pulsars are regularly observed these groups. A basic noise analysis, including processes both correlated uncorrelated in time, provides models ephemerides pulsars. find that...
Continued observations of the Double Pulsar, PSR J0737-3039A/B, consisting two radio pulsars (A and B) that orbit each other with a period 2.45hr in mildly eccentric (e=0.088) binary system, have led to large improvements measurement relativistic effects this system. With 16-yr data span, results enable precision tests theories gravity for strongly self-gravitating bodies also reveal new been expected but are now observed first time. These include light propagation strong gravitational...
Quantum fluctuations of the gravitational field in early Universe, amplified by inflation, produce a primordial gravitational-wave background across broad frequency band. We derive constraints on spectrum this radiation, and hence theories combining experiments that cover 29 orders magnitude frequency. These include Planck observations cosmic microwave temperature polarization power spectra lensing, together with baryon acoustic oscillations big bang nucleosynthesis measurements, as well new...
Abstract We present the third data release from Parkes Pulsar Timing Array (PPTA) project. The contains observations of 32 pulsars obtained using 64-m ‘Murriyang’ radio telescope. span is up to 18 yr with a typical cadence 3 weeks. This formed by combining an updated version our second $\sim$ more recent primarily ultra-wide-bandwidth receiver system that operates between 704 and 4032 MHz. provide calibrated pulse profiles, flux density dynamic spectra, times arrival, initial pulsar timing...