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Related papers: Frequency-Dependent Dispersion Measures and Implic…

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The ionized interstellar medium disperses pulsar radio signals, resulting in a stochastic time-variable delay known as the dispersion measure (DM) noise. In the wideband paradigm of pulsar timing, we measure a DM together with a time of…

Instrumentation and Methods for Astrophysics · Physics 2025-08-27 Abhimanyu Susobhanan , Rutger van Haasteren

We present multi-frequency scatter broadening evolution of 29 pulsars observed with the LOw Frequency ARray (LOFAR) and Long Wavelength Array (LWA). We conducted new observations using LOFAR Low Band Antennae (LBA) as well as utilized the…

High Energy Astrophysical Phenomena · Physics 2019-06-26 M. A. Krishnakumar , Yogesh Maan , Bhal Chandra Joshi , P. K. Manoharan

We present our results of pulse broadening time estimates and the study of the frequency scaling of this quantity for 60 pulsars based on actual multi-frequency scattering estimates. This research was based on our own measurements,…

Solar and Stellar Astrophysics · Physics 2015-06-23 Wojciech Lewandowski , Magdalena Kowalinska , Jaroslaw Kijak

Pulsars are the most stable natural frequency standards. They can be applied to a number of principal problems of modern astronomy and time-keeping metrology. The full exploration of pulsar properties requires obtaining unbiased estimates…

Data Analysis, Statistics and Probability · Physics 2009-10-31 Sergei M. Kopeikin

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

Pulsar timing experiments require high fidelity template profiles in order to minimize the biases in pulse time-of-arrival (TOA) measurements and their uncertainties. Efforts to acquire more precise TOAs given fixed effective area of…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Timothy T. Pennucci

Radio signals propagating through inhomogeneous plasma media deviate from their original paths, producing frequency-dependent magnification effects. In this paper, after reviewing the classical plasma-lensing theory, we have found a…

High Energy Astrophysical Phenomena · Physics 2025-09-26 Yu-Bin Wang , Xia Zhou , Abdusattar Kurban

Signals from radio pulsars show a wavelength-dependent delay due to dispersion in the interstellar plasma. At a typical observing wavelength, this delay can vary by tens of microseconds on five-year time scales, far in excess of signals of…

Precision pulsar timing requires optimization against measurement errors and astrophysical variance from the neutron stars themselves and the interstellar medium. We investigate optimization of arrival time precision as a function of radio…

High Energy Astrophysical Phenomena · Physics 2018-06-28 M. T. Lam , M. A. McLaughlin , J. M. Cordes , S. Chatterjee , T. J. W. Lazio

Pulsar timing at low frequencies offers a powerful tool for studying the interstellar medium. Additionally, pulsar observations in the ecliptic enables us to study the effects of the solar wind which becomes much more prominent at low radio…

High Energy Astrophysical Phenomena · Physics 2025-06-25 S. C. Susarla , O. A. Johnson , D. J. McKenna , E. F. Keane , P. J. McCauley , J. P. W. Verbiest , C. Tiburzi , A. Golden

The frequency dependence of radio pulse arrival times provides a probe of structures in the intervening media. Demorest et al. 2013 was the first to show a short-term (~100-200 days) reduction in the electron content along the line of sight…

Efforts are underway to use high-precision timing of pulsars in order to detect low-frequency gravitational waves. A limit to this technique is the timing noise generated by dispersion in the plasma along the line of sight to the pulsar,…

High Energy Astrophysical Phenomena · Physics 2022-02-04 P. Kumar , S. M. White , K. Stovall , J. Dowell , G. B. Taylor

A comparative analysis of the observational characteristics of fast radio bursts at the frequencies 111 and 1400 MHz is carried out. The distributions of radio bursts by the dispersion measure are constructed. At both frequencies, they are…

Instrumentation and Methods for Astrophysics · Physics 2021-09-27 V. A. Fedorova , A. E. Rodin

We analyse dispersion measure (DM) variations in six years of radio observations of more than 160 young pulsars, all gamma ray candidates for the Fermi gamma ray telescope mostly located close to the Galactic plane. DMs were fit across 256…

Astrophysics of Galaxies · Physics 2015-06-16 E. Petroff , M. J. Keith , S. Johnston , W. van Straten , R. M. Shannon

The turbulent nature of the ionised interstellar medium (IISM) causes dispersion measure (DM) and scattering variations in pulsar timing measurements. To improve precision of gravitational wave measurements, pulsar timing array (PTA)…

High Energy Astrophysical Phenomena · Physics 2025-11-06 A. D. Kulkarni , R. M. Shannon , D. J. Reardon , M. T. Miles

Pulsar Timing Array (PTA) collaborations gather high-precision timing measurements of pulsars with the aim of detecting gravitational wave (GW) signals. A major challenge lies in the identification and characterization of the different…

Interstellar scattering causes pulsar profiles to grow asymmetrically, thus affecting the pulsar timing residuals, and is strongest at lower frequencies. Different Interstellar medium models predict different frequency ($\nu$) and…

High Energy Astrophysical Phenomena · Physics 2019-05-01 Karishma Bansal , G. B. Taylor , Kevin Stovall , Jayce Dowell

In this paper, we describe a novel experiment for the accurate estimation of pulsar dispersion measures using the Giant Metre-wave Radio Telescope. This experiment was carried out for a sample of twelve pulsars, over a period of more than…

Astrophysics · Physics 2009-11-10 A. L. Ahuja , Y. Gupta , D. Mitra , A. K. Kembhavi

We present a robust approach to incorporating models for the time-variable broadening of the pulse profile due to scattering in the ionized interstellar medium into profile-domain pulsar timing analysis. We use this approach to…

Instrumentation and Methods for Astrophysics · Physics 2017-04-12 L. Lentati , M. Kerr , S. Dai , R. M. Shannon , G. Hobbs , S. Oslowski

Fast radio bursts (FRBs) are short-duration radio transients of unknown origin. Thus far, they have been blindly detected at millisecond timescales with dispersion measures (DMs) between 110--2600\,pc\,cm$^{-3}$. However, the observed pulse…

High Energy Astrophysical Phenomena · Physics 2019-07-10 Liam Connor