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Related papers: Associations Between Scattering Screens and Inters…

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The nature of irregularly spaced pulses of rotating radio transients (RRATs) complicates interstellar scintillation studies. In this letter, we report the primary scintillation parameters of a sample of RRATs using pairwise correlations of…

Extreme Scattering Events and pulsar secondary spectra have highlighted fundamental problems in our understanding of the dynamics of interstellar turbulence. We describe some of these problems in detail and present the theory behind the…

Astrophysics of Galaxies · Physics 2015-06-11 Jean-Pierre Macquart

Refraction of pulsar radiation by electron density irregularities in the interstellar medium sometimes produces multiple imaging of pulsars which can lead to periodic oscillations of intensity in pulsar dynamic spectra records. Such events…

Astrophysics · Physics 2007-05-23 Yashwant Gupta , N. D. Ramesh Bhat , A. Pramesh Rao

We comment on recent spectropolarimetric studies that compare the observed polarization position angles (PAs) of Seyfert 1 galaxies near H alpha with the observed orientations of their radio source axes on the sky. For a Seyfert galaxy in…

Sub-millimetre observations suggest that the filaments of interstellar clouds have rather uniform widths and can be described with the so-called Plummer profiles. The shapes of the filament profiles are linked to their physical state.…

Astrophysics of Galaxies · Physics 2015-06-05 M. Juvela , J. Malinen , T. Lunttila

We have used the University of Tasmania's 30 m radio telescope at Ceduna in South Australia to regularly monitor the flux density of a number of southern blazars. We report the detection of an annual cycle in the variability timescale of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Steven J. B. Carter , Simon P. Ellingsen , Jean-Pierre Macquart , James E. J. Lovell

(Abridged) We present in this paper a sample of 14 nearby clusters of galaxies observed with the ROSAT/PSPC. We only select clusters with low galactic nH in order to trace the X-ray emitting intra-cluster medium (ICM) out to large radii. We…

Astrophysics · Physics 2009-11-11 D. M. Neumann

The effect of interplanetary plasma on pulsed pulsar radiation passing through is considered. The pulses of two rotating radio transients (J0609+16, J1132+25) and a pulsar (B0320+39) detected on the Large Phased Array (Pushchino…

High Energy Astrophysical Phenomena · Physics 2023-05-24 S. A. Tyul'bashev , I. V. Chashei , M. A. Kitaeva

Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features…

Astrophysics · Physics 2009-11-10 James M. Cordes , Barney J. Rickett , Daniel R. Stinebring , William A. Coles

In order to investigate the contribution of diffuse components to their total HI emission, we have obtained high precision HI line flux densities with the 100m Green Bank Telescope for a sample of 100 isolated spiral and irregular galaxies…

Astrophysics · Physics 2008-11-26 David E. Hogg , Morton S. Roberts , Martha P. Haynes , Ronald J. Maddalena

This article describes simulations of scattering of annihilation gamma quanta in a strip of plastic scintillator. Such strips constitute basic detection modules in a newly proposed Positron Emission Tomography which utilizes plastic…

Debris disks or belts are important signposts for the presence of colliding planetesimals and, therefore, for ongoing planet formation and evolution processes in young planetary systems. Imaging of debris material at small separations from…

Earth and Planetary Astrophysics · Physics 2018-10-24 N. Engler , H. M. Schmid , S. P. Quanz , H. Avenhaus , A. Bazzon

We investigate the feasibility of detecting and probing various components of the ionized intergalactic medium (IGM) and their turbulent properties at radio frequencies through observations of scatter broadening of compact sources. There is…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-01 J. Y. Koay , J. -P. Macquart

The properties of filamentary interstellar clouds observed at sub-millimetre wavelengths, especially by the Herschel Space Observatory, are analysed with polytropic models in cylindrical symmetry. The observed radial density profiles are…

Solar and Stellar Astrophysics · Physics 2015-06-23 Claudia Toci , Daniele Galli

Most galaxies are hosted by massive, invisible dark matter haloes, yet little is known about the scatter in the stellar mass--halo mass relation for galaxies with host halo masses $M_{h}\le 10^{11}M_{\odot}$. Using mock catalogues based on…

Astrophysics of Galaxies · Physics 2019-08-14 Magdelena Allen , Peter Behroozi , Chung-Pei Ma

We investigate the linear polarization produced by interstellar dust aligned by the magnetic field in the solar neighborhood (d< 50 pc). We also look for intrinsic effects from circumstellar processes, specifically in terms of polarization…

Astrophysics of Galaxies · Physics 2020-03-11 V. Piirola , A. Berdyugin , P. C. Frisch , M. Kagitani , T. Sakanoi , S. Berdyugina , A. A. Cole , C. Harlingten , K. Hill

Plastic scintillation detectors are increasingly used to measure dose distributions in the context of radiotherapy treatments. Their water-equivalence, real-time response and high spatial resolution distinguish them from traditional…

Medical Physics · Physics 2021-09-22 Emily Cloutier , Louis Archambault , Luc Beaulieu

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

We performed observations of the Sco-Cen F star HD 117214 aiming at a search for planetary companions and the characterization of the debris disk structure. HD 117214 was observed with the SPHERE subsystems IRDIS, IFS and ZIMPOL at optical…

Extreme scattering events (ESEs) are distinctive fluctuations in the brightness of astronomical radio sources caused by occulting plasma lenses in the interstellar medium. The inferred plasma pressures of the lenses are $\sim 10^3$ times…