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相关论文: The effect of Pulse profile evolution on Pulsar Di…

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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…

天体物理学 · 物理学 2009-11-10 A. L. Ahuja , Y. Gupta , D. Mitra , A. K. Kembhavi

Aims. We explore frequency-dependent changes in pulsar radio emission by analyzing their profile widths and emission heights, assessing whether the simple radius-to-frequency mapping (RFM) or the fan beam model can describe the data.…

高能天体物理现象 · 物理学 2026-01-14 P. Jaroenjittichai , S. Johnston , S. Dai , M. Kerr , M. E. Lower , R. N. Manchester , L. S. Oswald , R. M. Shannon , C. Sobey , P. Weltevrede

We extend profile domain pulsar timing to incorporate wide-band effects such as frequency-dependent profile evolution and broadband shape variation in the pulse profile. We also incorporate models for temporal variations in both pulse width…

We analyze the frequency dependence of the dispersion measure (DM), the column density of free electrons to a pulsar, caused by multipath scattering from small scale electron-density fluctuations. The DM is slightly different along each…

天体物理仪器与方法 · 物理学 2016-01-21 J. M. Cordes , R. M. Shannon , D. R. Stinebring

Propagation effects in the interstellar medium and intrinsic profile changes can cause variability in the timing of pulsars, which limits the accuracy of fundamental science done via pulsar timing. One of the best timing pulsars, PSR…

高能天体物理现象 · 物理学 2021-10-07 Fang Xi Lin , Hsiu-Hsien Lin , Jing Luo , Robert Main , James McKee , Ue-Li Pen , Dana Simard , Marten H. van Kerkwijk

A pulsar's pulse profile gets broadened at low frequencies due to dispersion along the line of sight or due to multi-path propagation. The dynamic nature of the interstellar medium makes both of these effects time-dependent and introduces…

Making precise measurements of pulsar dispersion measures (DMs) and applying suitable corrections for them is amongst the major challenges in high-precision timing programmes such as pulsar timing arrays (PTAs). While the advent of…

高能天体物理现象 · 物理学 2022-05-25 Dilpreet Kaur , N. D. Ramesh Bhat , Shi Dai , Samuel J. McSweeney , Ryan M. Shannon , Sanjay Kudale , Willem van Straten

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…

天体物理学 · 物理学 2009-11-10 O. Loehmer , D. Mitra , Y. Gupta , M. Kramer , A. Ahuja

We present an analysis of the variations seen in the dispersion measures (DMs) of 20 millisecond pulsars observed as part of the Parkes Pulsar Timing Array project. We carry out a statistically rigorous structure function analysis for each…

We present the results from nearly three years of monitoring of the variations in dispersion measure (DM) along the line-of-sight to 11 millisecond pulsars using the Giant Metrewave Radio Telescope (GMRT). These results demonstrate…

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,…

太阳与恒星天体物理 · 物理学 2015-06-23 Wojciech Lewandowski , Magdalena Kowalinska , Jaroslaw Kijak

Pulsar radio emission undergoes dispersion due to the presence of free electrons in the interstellar medium (ISM). The dispersive delay in the arrival time of pulsar signal changes over time due to the varying ISM electron column density…

We analyze deterministic and random temporal variations in dispersion measure (DM) from the full three-dimensional velocities of pulsars with respect to the solar system, combined with electron-density variations on a wide range of length…

高能天体物理现象 · 物理学 2016-09-29 Michael T. Lam , James M. Cordes , Shami Chatterjee , Megan L. Jones , Maura A. McLaughlin , John W. Armstrong

Radio pulses from pulsars are affected by plasma dispersion, which results in a frequency-dependent propagation delay. Variations in the magnitude of this effect lead to an additional source of red noise in pulsar timing experiments,…

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…

星系天体物理 · 物理学 2015-06-16 E. Petroff , M. J. Keith , S. Johnston , W. van Straten , R. M. Shannon

We present high signal-to-noise ratio, multi-frequency polarization pulse profiles for 24 millisecond pulsars that are being observed as part of the Parkes Pulsar Timing Array (PPTA) project. The pulsars are observed in three bands, centred…

Pulsars are known to display short-term variability. Recently, examples of longer-term emission variability have emerged that are often correlated with changes in the rotational properties of the pulsar. To further illuminate this…

高能天体物理现象 · 物理学 2016-01-27 P. R. Brook , A. Karastergiou , S. Johnston , M. Kerr , R. M. Shannon , S. J. Roberts

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…

天体物理仪器与方法 · 物理学 2017-04-12 L. Lentati , M. Kerr , S. Dai , R. M. Shannon , G. Hobbs , S. Oslowski

Many models for the pulsar radio and $\gamma$-ray emissions have been developed. The tests for these models using observational data are very important. Tests for the pulsar radio emission models using frequency-altitude relation are…

天体物理学 · 物理学 2008-11-26 G. J. Qiao , K. J. Lee , H. G. Wang , R. X. Xu , B. Zhang

Context. High-precision pulsar-timing experiments are affected by temporal variations of the Dispersion Measure (DM), which are related to spatial variations in the interstellar electron content. Correcting for DM variations relies on the…

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