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Common signal-processing approximations produce artefacts when timing pulsars in relativistic binary systems, especially edge-on systems with tight orbits, such as the Double Pulsar. In this paper, we use extensive simulations to explore…

High Energy Astrophysical Phenomena · Physics 2025-02-19 Huanchen Hu , Nataliya K. Porayko , Willem van Straten , Michael Kramer , David J. Champion , Michael J. Keith

We show the results of our analysis of the pulse broadening phenomenon in 25 pulsars at several frequencies using the data gathered with GMRT and Effelsberg radiotelescopes. Twenty two of these pulsars were not studied in that regard before…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Wojciech Lewandowski , Marta Dembska , Jaroslaw Kijak , Magdalena Kowalinska

We analyze dispersion measure (DM) variations of 37 millisecond pulsars in the 9-year NANOGrav data release and constrain the sources of these variations. Variations are significant for nearly all pulsars, with characteristic timescales…

Fast radio bursts (FRBs) have excessive dispersion measures (DMs) and an all-sky distribution, which point toward an extragalactic or even a cosmological origin. We develop a method to extract the mean host galaxy DM ($\left\langle{\rm…

High Energy Astrophysical Phenomena · Physics 2017-04-26 Yuan-Pei Yang , Rui Luo , Zhuo Li , Bing Zhang

The widths, dispersion measures, dispersion indices and fluences of Fast Radio Bursts (FRB) impose coupled constraints that all models must satisfy. Observation of dispersion indices close to their low density limit of $-2$ sets a…

High Energy Astrophysical Phenomena · Physics 2016-05-04 J. I. Katz

We report discovery of several energetic radio bursts at 34 MHz, using the Gauribidanur radio telescope. The radio bursts exhibit two important properties associated with the propagation of astronomical signals through the interstellar…

Solar and Stellar Astrophysics · Physics 2015-12-23 Yogesh Maan

Density fluctuations in the ionised interstellar medium have a profound effect on radio pulsar observations, through angular scattering, intensity scintillations, and small changes in time delays from dispersion. Here we show that it is…

High Energy Astrophysical Phenomena · Physics 2023-04-12 Daniel J. Reardon , William A. Coles

Stellar coronae have been invoked to explain the apparently extragalactic dispersion measures observed in fast radio bursts. This paper demonstrates that the suggested plasma densities would lead to deviations from the standard dispersion…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-10 Artem V. Tuntsov

Fast radio bursts (FRBs) probe the total column density of free electrons in the intergalactic medium (IGM) along the path of propagation though the dispersion measures (DMs) which depend on the baryon mass fraction in the IGM, i.e.,…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-20 Ji-Ping Dai , Jun-Qing Xia

The scattering of fast radio bursts (FRBs) by the intergalactic medium (IGM) is explored using cosmological hydrodynamical simulations. We confirm that the scattering by the clumpy IGM has significant line-of-sight variations. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 Weishan Zhu , Long-Long Feng , Fupeng Zhang

Fast radio bursts (FRBs) are increasingly being used for cosmological applications such as measuring the Hubble constant and baryon abundance. The increasing number of localized FRBs and precise measurement of dispersion measure (DM) make…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-20 Sandeep Kumar Acharya , Paz Beniamini

The dispersion measure(DM) of fast radio burst encodes important information such as its distance, properties of intervening medium. Based on simulations in the Illustris and IllustrisTNG projects, we analyze the DM of FRBs contributed by…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Jian-Feng Mo , Weishan Zhu , Yang Wang , Lin Tang , Long-Long Feng

The dispersion measure of fast radio bursts (FRBs), arising from the interactions of the pulses with free electrons along the propagation path, constitutes a unique probe of the cosmic baryon distribution. Their constraining power is…

We investigate the impact of noise processes on high-precision pulsar timing. Our analysis focuses on the measurability of the second spin frequency derivative $\ddot{\nu}$. This $\ddot{\nu}$ can be induced by several factors including the…

High Energy Astrophysical Phenomena · Physics 2019-07-09 X. J. Liu , M. J. Keith , C. Bassa , B. W. Stappers

The Macquart relation describes the correlation between the dispersion measure (DM) of fast radio bursts (FRBs) and the redshift $z$ of their host galaxies. The scatter of the Macquart relation is sensitive to the distribution of baryons in…

One of the keys to interpreting the character and evolution of interstellar matter in the galaxy is understanding the distribution of the low density hot (10^5 K -10^6 K) phase of the interstellar medium (ISM). This phase is much more…

Astrophysics · Physics 2009-10-30 Eric J. Korpela , Stuart Bowyer , Jerry Edelstein

High precision cosmology with weak gravitational lensing requires a precise measure of the Point Spread Function across the imaging data where the accuracy to which high spatial frequency variation can be modelled is limited by the stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Catherine Heymans , Barnaby Rowe , Henk Hoekstra , Lance Miller , Thomas Erben , Thomas Kitching , Ludovic Van Waerbeke

Stochastic temporal wandering of the spin frequency $\nu$ of a rotation-powered pulsar (i.e.~the achromatic component of timing noise unrelated to interstellar propagation) affects the accuracy with which the secular braking torque can be…

High Energy Astrophysical Phenomena · Physics 2023-05-17 Andrés F. Vargas , Andrew Melatos

Infrared variability is common among young stellar objects, with surveys finding daily to weekly fluctuations of a few tenths of a magnitude. Space-based observations can produce highly sampled infrared light curves, but are often limited…

We consider future cosmological tests based on observations of Fast Radio Bursts (FRBs). We use Illustris Simulation to realistically estimate the scatter in the dispersion measure (DM) of FRBs caused by the inhomogeneous distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-12 M. Jaroszynski