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Related papers: Crab pulsar spectrum: a non-extensive approach

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We have measured the linear polarisation of hard X-ray emission from the Crab in a previously unexplored energy interval, 20-120 keV. The introduction of two new observational parameters, the polarisation fraction and angle stands to…

We present near-infrared observations obtained with ISAAC on the VLT of the Crab pulsar and its environment. Photometry of the pulsar in Js, H and Ks shows the pulsar spectrum to extend fairly smoothly from the UV/optical regime. PSF…

Astrophysics · Physics 2009-11-07 Jesper Sollerman

Our high-time-resolution observations reveal that individual main pulses from the Crab pulsar contain one or more short-lived microbursts. Both the energy and duration of bursts measured above 1 GHz can vary dramatically in less than a…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Jared H. Crossley , Jean A. Eilek , Timothy H. Hankins , Jeff S. Kern

We use a modified outer gap model to study the multi-frequency phase-resolved spectra of the Crab pulsar. The emissions from both poles contribute to the light curve and the phase-resolved spectra. Using the synchrotron self-Compton…

Astrophysics · Physics 2010-11-11 Anisia P. S. Tang , J. Takata , J. J. Jia , K. S. Cheng

We report the detection and observed characteristics of giant pulses from the Crab Nebula pulsar (B0531+21) in four frequency bands covering 20-84 MHz using the recently-completed Long Wavelength Array Station 1 (LWA1) radio telescope. In…

High Energy Astrophysical Phenomena · Physics 2015-06-15 S. W. Ellingson , T. E. Clarke , J. Craig , B. C. Hicks , T. J. W. Lazio , G. B. Taylor , T. L. Wilson , C. N. Wolfe

VLBI observations of the Crab pulsar with the 64-m radio telescope at Kalyazin (Russia) and the 46-m radio telescope of the Algonquin Radio Observatory (Canada) at 2.2 GHz and single-dish observations of the millisecond pulsar B1937+21 with…

We analytically examine the capabilities of rotation-powered pulsars as the sources of gamma-rays and show that their phase-averaged gamma-ray flux is proportional to the product of the spin-down flux and the gap trans-field thickness cubed…

Astrophysics · Physics 2009-11-13 Kouichi Hirotani

There are currently over 160 known gamma-ray pulsars. While most of them are detected only from space, at least two are now seen also from the ground. MAGIC and VERITAS have measured the gamma ray pulsed emission of the Crab pulsar up to…

High Energy Astrophysical Phenomena · Physics 2019-08-13 C. Alvarez Ochoa , P. M. Saz Parkinson , A. Belfiore , A. Carramiñana , C. Rivière , E. Moreno Barbosa

We show that the mysterious, rapidly variable emission at ~400 MeV observed from the Crab Nebula by the AGILE and Fermi experiments could be the result of a sudden drop in the mass-loading of the pulsar wind. The current required to…

High Energy Astrophysical Phenomena · Physics 2017-11-29 John G. Kirk , Gwenael Giacinti

In this paper we first provide a brief history of the handful of X-ray polarization measurements that have been accomplished to date. We then outline new technological developments that indicate more detailed polarization measurements in…

High Energy Astrophysical Phenomena · Physics 2009-08-19 Martin C. Weisskopf

We have investigated the pulse shape evolution of the Crab pulsar emission in the hard X-ray domain of the electromagnetic spectrum. In particular, we have studied the alignment of the Crab pulsar phase profiles measured in the hard X-rays…

High Energy Astrophysical Phenomena · Physics 2014-11-20 S. Molkov , E. Jourdain , J. P. Roques

We have converted the former solar electrical plant THEMIS (French Pyrenees) into an atmospheric Cherenkov detector called CELESTE, which records gamma rays above 30 GeV (7E24 Hz). Here we present the first sub-100 GeV detection by a ground…

Since 2009, several rapid and bright flares have been observed at high energies (>100 MeV) from the direction of the Crab Nebula. Several hypotheses have been put forward to explain this phenomenon, but the origin is still unclear. The…

High Energy Astrophysical Phenomena · Physics 2022-10-11 Enrique Mestre , Emma de Ona Wilhelmi , Dmitry Khangulyan , Roberta Zanin , Fabio Acero , Diego F. Torres

The Crab Nebula was discovered as the first very-high-energy gamma-ray source by the Whipple Observatory in 1989. Thirty years after its discovery it is still the reference source and the standard candle for Imaging Atmospheric Cherenkov…

Instrumentation and Methods for Astrophysics · Physics 2019-09-13 Michele Peresano , Razmik Mirzoyan , Ievgen Vovk , Petar Temnikov , Darko Zarić , Nikola Godinović , Juliane van Scherpenberg , Jüergen Besenrieder

In almost any scenario for 'cosmological' gamma-ray bursts (and in many models where they originate in our own Galaxy), the initial energy density is so large that the resulting relativistic plasma expands with $v\sim c$ producing a blast…

Astrophysics · Physics 2009-10-22 P. Meszaros , M. J. Rees

Recently the AGILE and Fermi/LAT detectors uncovered giant $\gamma$-ray flares from the Crab nebula. The duration of these flares is a few days. The Fermi/LAT data with monthly time binning further showed significant variability of the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Qiang Yuan , Peng-Fei Yin , Xue-Feng Wu , Xiao-Jun Bi , Siming Liu , Bing Zhang

We present a study of shape, spectra and polarization properties of giant pulses (GPs) from the Crab pulsar at the very high frequencies of 8.5 and 15.1 GHz. Studies at 15.1 GHz were performed for the first time. Observations were conducted…

We studied the evolution of the X-ray and gamma-ray spectra of the Crab pulsar utilizing the 11-year observations from the Rossi X-ray Timing Explorer (RXTE) and 9-year observations from the Fermi Gamma-ray Space Telescope (FGST). By…

High Energy Astrophysical Phenomena · Physics 2018-10-10 L. L. Yan , M. Y. Ge , F. J. Lu , S. J. Zheng , Y. L. Tuo , Z. J. Li , L. M. Song , J. L. Qu

The Crab pulsar has striking radio emission properties, with the two dominant pulse components -- the main pulse and the interpulse -- consisting entirely of giant pulses. The emission is scattered in both the Crab nebula and the…

Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar…

High Energy Astrophysical Phenomena · Physics 2015-06-16 D. J. Thompson