English
Related papers

Related papers: The dispersion in pulsar $\gamma$-ray efficiency

200 papers

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…

Instrumentation and Methods for Astrophysics · Physics 2016-01-21 J. M. Cordes , R. M. Shannon , D. R. Stinebring

The seven known gamma-ray pulsars represent a very small fraction of the more than 1000 presently known radio pulsars, yet they can give us valuable information about pulsar particle acceleration and energetics. Although the theory of…

Astrophysics · Physics 2007-05-23 Alice K. Harding

We continue our systematic statistical study on optical afterglow data of gamma-ray bursts (GRBs). We present the apparent magnitude distributions of early optical afterglows at different epochs (t= 10^2 s, t = 10^3 s, and 1 hour) for the…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Xiang-Gao Wang , En-Wei Liang , Liang Li , Rui-Jing Lu , Jian-Yan Wei , Bing Zhang

Cosmic ray electrons and positrons are tracers of particle propagation in the interstellar medium (ISM). A recent measurement performed using H.E.S.S. extends the all-electron (electron+positron) spectrum up to 20TeV, probing very local…

High Energy Astrophysical Phenomena · Physics 2019-01-08 R. López-Coto , R. D. Parsons , J. A. Hinton , G. Giacinti

In 1997 October daily monitoring observations of the Crab pulsar at 327 MHz and 610 MHz with an 85ft telescope in Green Bank, WV showed a jump in the dispersion measure by 0.1 cm$^{-3}$ pc. Pulses were seen simultaneously at both old and…

Astrophysics · Physics 2016-08-30 D. C. Backer , T. Wong , J. Valanju

A large sample of pulsars was observed as part of the Meterwavelength Single-pulse Polarimetric Emission Survey. We carried out a detailed fluctuation spectral analysis which revealed periodic features in 46% pulsars including 22 pulsars…

High Energy Astrophysical Phenomena · Physics 2016-12-14 Rahul Basu , Dipanjan Mitra , George I. Melikidze , Krzysztof Maciesiak , Anna Skrzypczak , Andrzej Szary

Propagation of radio emission in pulsar magnetosphere is reviewed. The effects of polarization transfer, induced scattering and reprocessing to high energies are analysed with an especial emphasis on the implications for the gamma-ray…

High Energy Astrophysical Phenomena · Physics 2016-04-22 S. A. Petrova

We analyze the transfer function of a three-dimensional atomic Bragg beamsplitter formed by two counterpropagating pulsed Gaussian laser beams. Even for ultracold atomic ensembles, the transfer efficiency depends significantly on the…

Quantum Gases · Physics 2021-04-07 Antje Neumann , Martina Gebbe , Reinhold Walser

Wave dispersion in a pulsar plasma (a 1D, strongly magnetized, pair plasma streaming highly relativistically with a large spread in Lorentz factors in its rest frame) is discussed, motivated by interest in beam-driven wave turbulence and…

Plasma Physics · Physics 2019-07-31 M. Z. Rafat , D. B. Melrose , A. Mastrano

We have measured variations in scattering time scales in the Crab Pulsar over a 30-year period, using observations made at 610 MHz with the 42-ft telescope at Jodrell Bank Observatory. Over more recent years, where regular Lovell Telescope…

High Energy Astrophysical Phenomena · Physics 2018-07-18 J. W. McKee , A. G. Lyne , B. W. Stappers , C. G. Bassa , C. A. Jordan

The population of $\gamma$-ray emitting millisecond pulsars (MSPs) is studied by using Monte-Carlo techniques. We simulate the Galactic distributions of the MSPs, and apply the outer gap model for the $\gamma$-ray emission from each…

High Energy Astrophysical Phenomena · Physics 2017-02-22 J. Takata , Y. Wang , K. S. Cheng

The scattering of fast radio bursts (FRBs) by the intergalactic medium (IGM) is explored using cosmological hydrodynamical simulations. We confirm that the scattering by the clumpy IGM has significant line-of-sight variations. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 Weishan Zhu , Long-Long Feng , Fupeng Zhang

Intensity scintillations of radio pulsars are known to originate from interference between waves scattered by the electron density irregularities of interstellar plasma, often leading to parabolic arcs in the two-dimensional power spectrum…

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

Timing of Geminga gamma-ray pulsar is done using data of COS B and EGRET. It is shown, that errors in angular coordinates of sources similar to Geminga strongly influence a determination of $\ddot \nu$, so that at angular precision less…

Astrophysics · Physics 2007-05-23 G. S. Bisnovatyi-Kogan , S. V. Repin

Modern radio interferometers sensitive to low frequencies will make use of wide-band detectors. For such wide bandwidths, dispersive atmospheric effects introduce variations in the fringe delay which change through the band of the…

Instrumentation and Methods for Astrophysics · Physics 2011-01-25 I. Marti-Vidal

We apply a theory of wave propagation through a turbulent medium to the scattering of radio waves in pulsar magnetospheres. We find that under conditions of strong density modulation the effects of magnetospheric scintillations in…

Astrophysics · Physics 2009-10-31 Maxim Lyutikov , Anuj Parikh

In order to examine the pulse profile from a pulsar, we derive the formula for describing the flux from antipodal hot spots with any static, spherically symmetric spacetime. We find that the pulse profiles are almost independent of the…

High Energy Astrophysical Phenomena · Physics 2017-11-17 Hajime Sotani , Umpei Miyamoto

Pulsars are highly magnetized rotating neutron stars with a very stable rotation speed. Irrespective of their stable rotation rate, many pulsars have been observed with the sudden jump in the rotation rate, which is known as pulsar glitch.…

High Energy Astrophysical Phenomena · Physics 2018-10-24 Avishek Basu , Prasanta Char , Rana Nandi , Bhal Chandra Joshi , Debades Bandyopadhyay

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…

High Energy Astrophysical Phenomena · Physics 2016-01-27 P. R. Brook , A. Karastergiou , S. Johnston , M. Kerr , R. M. Shannon , S. J. Roberts