A5017243863- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Stellar, planetary, and galactic studies
- High-pressure geophysics and materials
- Astronomical Observations and Instrumentation
- Superconducting Materials and Applications
- Astronomy and Astrophysical Research
- Geophysics and Sensor Technology
- Particle Accelerators and Free-Electron Lasers
- Advanced Frequency and Time Standards
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Magnetic confinement fusion research
- Inertial Sensor and Navigation
- GNSS positioning and interference
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Cosmology and Gravitation Theories
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Cold Atom Physics and Bose-Einstein Condensates
South African Radio Astronomy Observatory
2018-2024
SKA Telescope, South Africa
2016-2019
Columbia University
2007-2016
University of Puerto Rico at Arecibo
2000-2015
Australia Telescope National Facility
2004-2015
Commonwealth Scientific and Industrial Research Organisation
2004-2015
Astronomy and Space
2015
Arecibo Observatory
2012-2013
Swinburne University of Technology
2012
SKA Observatory
1996-2008
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...
The clocklike properties of pulsars moving in the gravitational fields their unseen neutron-star companions have allowed unique tests general relativity and provided evidence for radiation. We report here detection 2.8-second pulsar J0737-3039B as companion to 23-millisecond J0737-3039A a highly relativistic double neutron star system, allowing unprecedented fundamental physics. observed short eclipse by orbital modulation flux density pulse shape J0737-3039B, probably because influence...
We have discovered a 716-hertz eclipsing binary radio pulsar in the globular cluster Terzan 5 using Green Bank Telescope. It is fastest spinning neutron star found to date, breaking 24-year record held by 642-hertz B1937+21. The difficulty detecting this pulsar, because of its very low flux density and high eclipse fraction (approximately 40% orbit), suggests that even faster stars exist. If has mass less than twice Sun, then radius must be constrained spin rate <16 kilometers. short period...
This catalog summarizes 117 high-confidence ⩾0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on Fermi satellite. Half are neutron stars discovered LAT through periodicity searches in and radio around unassociated source positions. The pulsars evenly divided into groups: millisecond pulsars, young radio-loud radio-quiet pulsars. We characterize pulse profiles energy spectra derive luminosities when distance information exists. Spectral...
The Parkes multi-beam pulsar survey is a sensitive of strip along the Galactic plane with and to . It uses 13-beam receiver on 64-m radio telescope, receiving two polarizations per beam over 288-MHz bandwidth centred 1374 MHz. data acquisition systems are described in some detail. For periods range dispersion measures less than 300 cm−3 pc, nominal limiting flux density about 0.2 mJy. At shorter or longer higher dispersions, sensitivity reduced. Timing observations carried out for pulsars...
[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...
Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities for probing the intergalactic medium; may also be linked new source classes. Until now, however, all so-called fast (FRBs) detected Parkes telescope and its 13-beam receiver, casting some concern about...
The dramatic increase in the number of known gamma-ray pulsars since launch Fermi Gamma-ray Space Telescope (formerly GLAST) offers first opportunity to study a sizable population these high-energy objects. This catalog summarizes 46 high-confidence pulsed detections using six months data taken by Large Area (LAT), Fermi's main instrument. Sixteen previously unknown were discovered searching for signals at positions bright sources seen with LAT, or objects suspected be neutron stars based on...
ABSTRACT We report on radio and X-ray observations of the only known repeating Fast Radio Burst (FRB) source, FRB 121102. have detected six additional bursts from this source: five with Green Bank Telescope at 2 GHz, one 1.4 GHz Arecibo Observatory, for a total 17 source. All dispersion measures consistent single value (∼559 pc cm −3 ) that is three times predicted maximum Galactic contribution. The highly variable spectra like those indicating frequency structure seen across individual...
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...
Abstract We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for newly commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. is a high-gain ( ${\sim}2.8\,\mbox{K Jy}^{-1}$ ) low-system temperature ${\sim}18\,\mbox{K at }20\,\mbox{cm}$ array that currently operates 580–1 670 MHz can produce tied-array beams suitable observations. This paper presents MeerTime Large Survey Project commissioning with PTUSE. Highlights include...
Abstract The inner ∼200 pc region of the Galaxy contains a 4 million M ⊙ supermassive black hole (SMBH), significant quantities molecular gas, and star formation cosmic-ray energy densities that are roughly two orders magnitude higher than corresponding levels in Galactic disk. At distance only 8.2 kpc, presents astronomers with unique opportunity to study diverse range energetic astrophysical phenomena, from stellar objects extreme environments, SMBH star-formation-driven feedback processes...
Abstract We present 294 pulsars found in GeV data from the Large Area Telescope (LAT) on Fermi Gamma-ray Space Telescope. Another 33 millisecond (MSPs) discovered deep radio searches of LAT sources will likely reveal pulsations once phase-connected rotation ephemerides are achieved. A further dozen optical and/or X-ray binary systems colocated with also harbor gamma-ray MSPs. This catalog thus reports roughly 340 and candidates, 10% all known pulsars, compared to ≤11 before Fermi. Half...
We report on the newly increased event rates due to recent discovery of highly relativistic binary pulsar J0737-3039. Using a rigorous statistical method, we present calculations reported by Burgay et al., which produce coalescence rate for Galactic double neutron star (DNS) systems that is higher factor 6-7 compared estimates made prior new discovery. Our method takes into account known survey selection effects and biases small-number statistics. This increase has dramatic implications...
We have made observations of 98 low-Galactic-latitude pulsars to measure pulse broadening caused by multipath propagation through the interstellar medium. Data were collected with 305-m Arecibo telescope at four radio frequencies between 430 and 2380 MHz. used a CLEAN-based algorithm deconvolve from measured shapes. employed two distinct functions (PBFs): PBF$_1$ is appropriate for thin screen scattering material Earth pulsar, while PBF$_2$ uniformly distributed along line sight pulsar....
We have identified 21 millisecond pulsars (MSPs) in globular cluster Terzan 5 by using the Green Bank Telescope, bringing total of known MSPs to 24. These discoveries confirm fundamental predictions and binary system evolution. Thirteen new are binaries, which two show eclipses highly eccentric orbits. The relativistic periastron advance for systems indicates that at least one these has a mass 1.68 times greater than Sun 95% confidence. Such large neutron star masses constrain equation state...
The extreme physical conditions in millisecond pulsar magnetospheres, as well an evolutionary history that differs from of normal pulsars, raise the question whether these objects also differ their radio emission properties. We have monitored a large sample pulsars for period 3 yr using 100 m Effelsberg telescope order to compare properties two populations. Our comprises homogeneous data set very high quality. With some notable exceptions, our findings suggest groups share many common A...
We report on gamma-ray observations of the Crab Pulsar and Nebula using 8 months survey data with Fermi Large Area Telescope (LAT). The high quality light curve obtained ephemeris provided by Nancay Jodrell Bank radio telescopes shows two main peaks stable in phase energy. first peak leads pulse (281 \pm 12 21) mus, giving new constraints production site non-thermal emission pulsar magnetospheres. improved sensitivity unprecedented statistics afforded LAT enable precise measurement spectral...
The variable X-ray source 1E 1547.0-5408 was identified by Gelfand & Gaensler (2007) as a likely magnetar in G327.24-0.13, an apparent supernova remnant. No pulsations have been detected from it. Using the Parkes radio telescope, we discovered with period P = 2.069 s. Australia Telescope Compact Array, localized these to 1547.0-5408. We measure dP/dt (2.318+-0.005)e-11, which for magnetic dipole rotating vacuo gives surface field strength of 2.2e14 G, characteristic age 1.4 kyr, and...