English
Related papers

Related papers: Scattering study of Pulsars below 100 MHz using LW…

200 papers

We present here the results from an extensive scintillation study of twenty pulsars in the dispersion measure (DM) range 3 - 35 pc cm^-3 carried out using the Ooty Radio Telescope, to investigate the distribution of ionized material in the…

Astrophysics · Physics 2009-10-30 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

We present here the results from an extensive scintillation study of twenty pulsars in the dispersion measure (DM) range 3 - 35 pc cm^-3 caried out using the Ooty Radio Telescope (ORT) at 327 MHz, to investigate the distribution of ionized…

Astrophysics · Physics 2009-10-30 N. D. Ramesh Bhat , Yashwant Gupta , A. Pramesh Rao

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

The observing signals from pulsar are always influenced by the interstellar medium (ISM) scattering. In the lower frequency observation, the intensity profiles are broadened and the plane of polarization angle (PPA) curves are flattened by…

Solar and Stellar Astrophysics · Physics 2015-06-16 Abdujappar Rusul , Ali Esamdin , Xiao-Ping Zheng , Jian-Ping Yuan

Pulsar dispersion measures (DMs) have been used to model the electron density of the interstellar medium (ISM) in the Galactic disk as a plane-parallel medium, despite significant scatter in the DM-distance distribution and strong evidence…

Astrophysics of Galaxies · Physics 2020-07-10 Stella Koch Ocker , James M. Cordes , Shami Chatterjee

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…

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 the 305-m Arecibo telescope at four radio frequencies…

Pulsar scintillation can be used to measure small scale structure in the Galaxy, but little is known about the specific interstellar medium features that cause scintillation. We searched for interstellar medium counterparts to all…

High Energy Astrophysical Phenomena · Physics 2025-06-04 Ashley M. Stock , Marten H. van Kerkwijk

We present multi-wavelength scatter broadening observations of 47 pulsars, made with the Giant Metre-wave Radio Telescope (GMRT), Ooty Radio Telescope (ORT) and Long Wavelength Array (LWA). The GMRT observations have been made in the phased…

High Energy Astrophysical Phenomena · Physics 2017-09-13 M. A. Krishnakumar , Bhal Chandra Joshi , P. K. Manoharan

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

Weak interstellar scintillations of pulsar B0809+74 were observed at two epochs using a 30m EISCAT antenna at 933 MHz. These have been used to constrain the spectrum, the distribution and the transverse velocity of the scattering plasma…

Astrophysics · Physics 2015-06-24 Barney Rickett , Bill Coles , Jussi Markkanen

Interstellar scattering is known to broaden distant objects spatially and temporally. The latter aspect is difficult to analyse, unless the signals carry their own time stamps. Pulsars are so kind to do us this favour. Typically the…

Astrophysics of Galaxies · Physics 2019-04-26 Olaf Wucknitz

We use VLBA+VLA observations to measure the sizes of the scatter-broadened images of 6 of the most heavily scattered known pulsars: 3 within the Galactic Centre (GC) and 3 elsewhere in the inner Galactic plane. By combining the measured…

Astrophysics of Galaxies · Physics 2017-08-30 J. Dexter , A. Deller , G. C. Bower , P. Demorest , M. Kramer , B. W. Stappers , A. G. Lyne , M. Kerr , L. G. Spitler , D. Psaltis , M. Johnson , R. Narayan

We report on an effort to extract and monitor interstellar scintillation parameters in regular timing observations collected for the NANOGrav pulsar timing array. Scattering delays are measured by creating dynamic spectra for each pulsar…

We show that surface waves along interstellar current sheets closely aligned with the line of sight lead to pulsar scintillation properties consistent with those observed. This mechanism naturally produces the length and density scales of…

Astrophysics of Galaxies · Physics 2015-06-15 Ue-Li Pen , Yuri Levin

This paper considers scattering screens that have arbitrary spatial variations of scattering strength transverse to the line of sight, including screens that are spatially well confined, such as disks and filaments. We calculate the…

Astrophysics · Physics 2009-10-31 J. M. Cordes , T. Joseph W. Lazio

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 present initial pulsar results from the first station of the Long Wavelength Array (LWA1) obtained during the commissioning period of LWA1 and early science results. We present detections of periodic emission from 44 previously known…

Instrumentation and Methods for Astrophysics · Physics 2015-08-06 K. Stovall , P. S. Ray , J. Blythe , J. Dowell , T. Eftekhari , A. Garcia , T. J. W. Lazio , M. McCrackan , F. K. Schinzel , G. B. Taylor

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…

High Energy Astrophysical Phenomena · Physics 2016-09-29 Michael T. Lam , James M. Cordes , Shami Chatterjee , Megan L. Jones , Maura A. McLaughlin , John W. Armstrong

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…