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Related papers: High Precision Measurements of Interstellar Disper…

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In this paper we report multi-frequency measurements of pulse broadening times (tau_d) for nine medium dispersion measure (DM $\approx 150-400$ pc cm$^{-3}$) pulsars observed over a wide frequency range. The low frequency data at 243, 325…

Astrophysics · Physics 2009-11-10 O. Loehmer , D. Mitra , Y. Gupta , M. Kramer , A. Ahuja

The dispersion measure (DM) is one of the key attributes of radio pulsars and Fast Radio Bursts (FRBs). There is a mistaken view that the DM is an accurate measure of the column density of electrons between the observer and the source. To…

High Energy Astrophysical Phenomena · Physics 2020-07-07 S. R. Kulkarni

We report here on variable propagation effects in over twenty years of multi-frequency timing analysis of pulsar PSR B1937+21 that determine small-scale properties of the intervening plasma as it drifts through the sight line. The phase…

Astrophysics · Physics 2009-11-11 R. Ramachandran , P. Demorest , D. C. Backer , I. Cognard , A. Lommen

Timing pulses of pulsars has proved to be a most powerful technique useful to a host of research areas in astronomy and physics. Importantly, the precision of this timing is not only affected by radiometer noise, but also by intrinsic pulse…

High Energy Astrophysical Phenomena · Physics 2015-05-28 K. Liu , J. P. W. Verbiest , M. Kramer , B. W. Stappers , W. van Straten , J. M. Cordes

We report here on the timing of 597 pulsars over the last four years with the MeerKAT telescope. We provide Times-of-Arrival, pulsar ephemeris files and per-epoch measurements of the flux density, dispersion measure (DM) and rotation…

High Energy Astrophysical Phenomena · Physics 2024-04-03 M. J. Keith , S. Johnston , A. Karastergiou , P. Weltevrede , M. E. Lower , A. Basu , B. Posselt , L. S. Oswald , A. Parthasarathy , A. D. Cameron , M. Serylak , S. Buchner

Noise characterization for pulsar-timing applications accounts for interstellar dispersion by assuming a known frequency-dependence of the delay it introduces in the times of arrival (TOAs). However, calculations of this delay suffer from…

We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18 years. It forms the basis for…

Interstellar scintillation analysis of pulsars allows us to probe the small-scale distribution and inhomogeneities of the ionized interstellar medium. Our priority is to present the data set and the basic measurements of scintillation…

High-precision timing of millisecond pulsars (MSPs) over years to decades is a promising technique for direct detection of gravitational waves at nanohertz frequencies. Time-variable, multi-path scattering in the interstellar medium is a…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Anne M. Archibald , Vladislav I. Kondratiev , Jason W. T. Hessels , Daniel R. Stinebring

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…

Instrumentation and Methods for Astrophysics · Physics 2013-01-14 W. van Straten

The major programme for observing young, non-recycled pulsars with the Parkes telescope has transitioned from a narrow-band system to an ultra-wideband system capable of observing between 704 and 4032 MHz. We report here on the initial two…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Simon Johnston , C. Sobey , S. Dai , M. Keith , M. Kerr , R. N. Manchester , L. S. Oswald , A. Parthasarathy , R. M. Shannon , P. Weltevrede

The pulsar timing array systems have reported a detection of a nanohertz-band stochastic gravitational wave background in our galaxy. It is of interest to use this observation to probe modified gravity and to forecast the sensitivity with…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-19 Jonathan Grée , Qiuyue Liang , Elisa G. M. Ferreira

At 327 MHz, the observed emission of PSR B1937+21 is greatly affected by scattering in the interstellar medium, on a timescale of order the pulse period. We use the bright impulsive giant pulses emitted by the pulsar to measure the impulse…

High Energy Astrophysical Phenomena · Physics 2024-04-09 Nikhil Mahajan , Marten H. van Kerkwijk

Light travel time changes due to gravitational waves may be detected within the next decade through precision timing of millisecond pulsars. Removal of frequency-dependent interstellar medium (ISM) delays due to dispersion and scattering is…

Instrumentation and Methods for Astrophysics · Physics 2015-12-16 Nipuni Palliyaguru , Daniel Stinebring , Maura McLaughlin , Paul Demorest , Glenn Jones

Multiple studies have investigated potential frequency-dependent dispersion measures (DM) in PSR B0329+54, with sensitivities at levels of $10^{-3} \, \text{pc} \, \text{cm}^{-3}$ or higher, using frequencies below 1 GHz. Utilizing the…

High Energy Astrophysical Phenomena · Physics 2025-01-07 Shyam S. Sharma , Tetsuya Hashimoto , Tomotsugu Goto , Shotaro Yamasaki , Simon C. -C. Ho

We present simulations of scattering phenomena which are important in pulsar observations, but which are analytically intractable. The simulation code, which has also been used for solar wind and atmospheric scattering problems, is…

Astrophysics of Galaxies · Physics 2015-05-19 W. A. Coles , B. J. Rickett , J. J. Gao , G. Hobbs , J. P. W. Verbiest

The turbulent ionized interstellar medium diffracts radio waves and makes them propagate in multiple paths. The pulse-broadening observed at low frequencies results from the scattering effect of interstellar clouds of ionized gas. During…

High Energy Astrophysical Phenomena · Physics 2025-06-18 W. C. Jing , J. L. Han , C. Wang , P. F. Wang , T. Wang , N. N. Cai , J. Xu , Z. L. Yang , D. J. Zhou , Yi Yan , W. Q. Su , X. Y. Gao , L. Xie

We report the discovery and timing of two pulsars from a sample of four circularly polarized sources identified in radio continuum images taken as part of the Australian SKA Pathfinder (ASKAP) Variables and Slow Transients (VAST) survey.…

High Energy Astrophysical Phenomena · Physics 2026-03-17 Rahul Sengar , David L. Kaplan , Emil Lenc , Akash Anumarlapudi , Natasha Hurley-Walker , Ziteng Wang , Laura Driessen , Dougal Dobie , Tara Murphy