Results 31 to 40 of about 6,025 (156)
Asymmetry function of interstellar scintillations of pulsars
Astronomy Reports, 2005 A new method for separating intensity variations of a source's radio emission having various physical natures is proposed. The method is based on a joint analysis of the structure function of the intensity variations and the asymmetry function, which is a generalization of the asymmetry coefficient and characterizes the asymmetry of the distribution ...
Shishov, V. I., Smirnova, T. V.
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Scintillations and Levy Flights through the Interstellar Medium [PDF]
The Astrophysical Journal, 2003 Temporal broadening of pulsar signals results from electron density fluctuations in the interstellar medium that cause the radiation to travel along paths of different lengths. The Gaussian theory of fluctuations predicts that the pulse temporal broadening should scale with the wavelength as lambda^4, and with the dispersion measure (corresponding to ...
Boldyrev, Stanislav, Gwinn, Carl
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Angular Broadening of Intraday Variable AGN. II. Interstellar and Intergalactic Scattering [PDF]
, 2007 We analyze a sample of 58 multi-wavelength, Very Long Baseline Array observations of active galactic nuclei (AGN) to determine their scattering properties.
Alan L. Fey +8 more
core +1 more source
Magnetic Reconnection in the Space Sciences: Past, Present, and Future
Journal of Geophysical Research: Space Physics, Volume 125, Issue 2, February 2020., 2020 Abstract Magnetic reconnection converts, often explosively, stored magnetic energy to particle energy in space and in the laboratory. Through processes operating on length scales that are tiny, it facilitates energy conversion over dimensions of, in some cases, hundreds of Earth radii.
M. Hesse, P. A. Cassak
wiley +1 more source
Interstellar scintillation observations for PSR B0355+54 [PDF]
Monthly Notices of the Royal Astronomical Society, 2018 In this paper, we report our investigation of pulsar scintillation phenomena by monitoring PSR B0355$+$54 at 2.25 GHz for three successive months using \emph{Kunming 40-m radio telescope}. We have measured the dynamic spectrum, the two-dimensional correlation function, and the secondary spectrum.
Xu, Yonghua +12 more
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Scattering Delay Mitigation in High-accuracy Pulsar Timing: Cyclic Spectroscopy Techniques
The Astrophysical Journal, 2023 We simulate scattering delays from the interstellar medium to examine the effectiveness of three estimators in recovering these delays in pulsar timing data. Two of these estimators use the more traditional process of fitting autocorrelation functions to
Jacob E. Turner +5 more
doaj +1 more source
A new approach to generate a catalogue of potential historical novae
Astronomische Nachrichten, Volume 341, Issue 1, Page 79-98, January 2020., 2020 Abstract Ancient Chinese, Korean, and Vietnamese observers left us records of celestial sightings, the so‐called “guest stars” dated up to ∼2500 years ago. Their identification with modern observable targets could open interesting insights into the long‐term behavior of astronomical objects, as shown by the successful identification of eight galactic ...
Susanne M. Hoffmann +2 more
wiley +1 more source
Detecting pulsars with interstellar scintillation in variance images [PDF]
Monthly Notices of the Royal Astronomical Society, 2016 Pulsars are the only cosmic radio sources known to be sufficiently compact to show diffractive interstellar scintillations. Images of the variance of radio signals in both time and frequency can be used to detect pulsars in large-scale continuum surveys using the next generation of synthesis radio telescopes.
Dai, S +6 more
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Scintillation in the Circinus Galaxy water megamasers
, 2004 We present observations of the 22 GHz water vapor megamasers in the Circinus galaxy made with the Tidbinbilla 70m telescope. These observations confirm the rapid variability seen earlier by Greenhill et al (1997).
David L. Jauncey +6 more
core +1 more source
Interstellar Scintillation of Pulsar Radiation
The Astrophysical Journal, 1969 Time fluctuations in the intensity of pulsed radiation from CP 0834, CP 1133, AP 1237, and CP 1919 have been investigated. Power spectra, modulation indices, frequency distributions, and decorrelation frequencies are consistent with scintillation theory.
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