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Interstellar scintillation analysis of pulsars allows us to probe the small-scale distribution and inhomogeneities of the ionized interstellar medium. Our priority is to present the data set and the basic measurements of scintillation…

Compact radio sources such as pulsars and FRBs undergo scintillation in the interstellar medium (ISM) when scattered images interfere at the observer. ``Scintillometry'' refers to the range of techniques to extract astrometric information…

High Energy Astrophysical Phenomena · Physics 2026-01-30 Dylan L. Jow , Delon Shen

Compact radio sources exhibit scintillation, an interference pattern arising from propagation through inhomogeneous plasma, where scintillation patterns encode the relative distances and velocities of the source, scattering material, and…

High Energy Astrophysical Phenomena · Physics 2023-06-26 R. A. Main , S. Bethapudi , V. R. Marthi , M. L. Bause , D. Z. Li , H. -H. Lin , L. G. Spitler , R. S. Wharton

Fast radio bursts (FRBs) are millisecond-timescale radio transients, the origins of which are predominantly extragalactic and likely involve highly magnetized compact objects. FRBs undergo multipath propagation, or scattering, from electron…

High Energy Astrophysical Phenomena · Physics 2022-12-14 S. K. Ocker , J. M. Cordes , S. Chatterjee , D. Li , C. H. Niu , J. W. McKee , C. J. Law , R. Anna-Thomas

A strong case has been made that radio waves from sources within about half a degree of the Galactic Center undergo extreme diffractive scattering. However, problems arise when standard (``Kolmogorov'') models of electron density…

Astrophysics · Physics 2009-11-11 Peter Goldreich , S. Sridhar

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 aim to search for evidence of annual modulation in the time scales of the BL Lac object S5 0716+714. The intra-day variability (IDV) observations were carried out monthly from 2005 to 2009, with the Urumqi 25m radio telescope at 4.8 GHz.…

High Energy Astrophysical Phenomena · Physics 2012-07-12 X. Liu , H. -G. Song , N. Marchili , B. -R. Liu , J. Liu , T. P. Krichbaum , L. Fuhrmann , J. A. Zensus

We present results of the analysis of interstellar scintillation in PSR B0823+26. Observations were conducted at a frequency of 1.7 GHz using the 32-m Torun Centre for Astronomy radio telescope. More than 50 observing sessions, lasting on…

High Energy Astrophysical Phenomena · Physics 2013-10-31 M. Daszuta , W. Lewandowski , J. Kijak

Recent infrared (IR) observations of the center of our Galaxy indicate that the supermassive black hole source Sgr A* is strongly variable in the IR. The timescale for the variability, $\sim 30$ min, is comparable to that of the X-ray…

Astrophysics · Physics 2009-11-10 Feng Yuan , Eliot Quataert , Ramesh Narayan

Young stellar objects are known to exhibit strong radio variability on timescales of weeks to months, and a few reports have documented extreme radio flares, with at least an order of magnitude change in flux density on timescales of hours…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Jan Forbrich , Mark J. Reid , Karl M. Menten , Victor Rivilla , Scott J. Wolk , Urvashi Rau , Claire J. Chandler

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

The ionizing spectral energy distribution of quasars exhibits a steepening of the distribution shortward of ~ 1200 A. The change of the power-law index from approximately -1 (near-UV) to -2 (far-UV) has so far been interpreted as being…

Astrophysics · Physics 2009-11-07 Luc Binette , Mario Rodriguez-Martinez , Sinhue Haro-Corzo , Isidro Ballinas

We present the first large sample of scintillation arcs in millisecond pulsars, analysing 12 sources observed with the Large European Array for Pulsars (LEAP), and the Effelsberg 100\,m telescope. We estimate the delays from multipath…

The Interstellar Medium (ISM) is a complex, multi-phase system, where the history of the stars occurs. The processes of birth and death of stars are strongly coupled to the dynamics of the ISM. The observed chaotic and diffusive motions of…

Astrophysics of Galaxies · Physics 2011-02-02 D. Falceta-Goncalves

The search for compact components of strong ($S_{int} \ge 5$ Jy at 102.5 MHz) discrete radio sources from the Pushchino catalogue was carried out using the method of interplanetary scintillation. A total of 3620 sources were examined, and…

High Energy Astrophysical Phenomena · Physics 2022-07-18 S. A. Tyul'bashev , I. V. Chashei , I. A. Subaev , M. A. Kitaeva

Radio pulsars, as highly coherent point sources, serve as powerful probes of the ionized interstellar medium (IISM). Pulsar scintillation observations have revealed inverted arclets on the secondary spectrum, indicating quasilinearly…

Astrophysics of Galaxies · Physics 2026-04-14 Zhu Xu , Xun Shi

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…

We derive the distribution of interferometric visibility for a source exhibiting strong diffractive scintillation, with particular attention to spectral resolution at or near the Nyquist limit. We also account for arbitrary temporal…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Michael D. Johnson , Carl R. Gwinn

We compare signal and noise for observations of the scintillating pulsar B0834+06, using very-long baseline interferometry and a single-dish spectrometer. Comparisons between instruments and with models suggest that amplitude variations of…

Astrophysics of Galaxies · Physics 2015-05-27 C. R. Gwinn , M. D. Johnson , T. V. Smirnova , D. R. Stinebring

Variability in gravitationally lensed quasars can be due to intrinsic fluctuations of the quasar or due to ``microlensing'' by compact objects along the line of sight. If disentangled from each other, microlens-induced variability can be…

Astrophysics · Physics 2007-05-23 Joachim Wambsganss
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