Results 11 to 20 of about 12,273 (135)
Gamma-ray flux depressions of the Crab nebula in the high-energy range [PDF]
MNRAS 496 (2020) 5227-5232, 2020 The giant gamma-ray flares of the Crab nebula discovered by AGILE and Fermi observatories came as a surprise and have challenged the existing models of pulsar wind nebulae. We have carried out an analysis of 10.5 years of Fermi-LAT observations (Aug 2008 -- Feb 2019) and investigated variability of the Crab nebula in the 100-300 MeV range.
arxiv +1 more source
Gamma rays and neutrinos from the Crab Nebula produced by pulsar accelerated nuclei [PDF]
Phys.Rev.Lett.79:2616-2619,1997, 1997 We investigate the consequences of the acceleration of heavy nuclei (e.g. iron nuclei) by the Crab pulsar. Accelerated nuclei can photodisintegrate in collisions with soft photons produced in the pulsar's outer gap, injecting energetic neutrons which decay either inside or outside the Crab Nebula.
arxiv +1 more source
ChemPhysChem, Volume 19, Issue 15, Page 1866-1875, August 7, 2018., 2018 Time to scatter: Quantum scattering calculations are presented for rotational state‐changing cross sections and rates, up to about 50 K of ion translational temperatures, for the OH+ molecular ion in collision with He atoms as the buffer gas in the trap.
L. González‐Sánchez +2 more
wiley +1 more source
Observations of the Crab Nebula with the HEGRA system of IACTs in convergent mode using a topological trigger [PDF]
Astropart.Phys. 19 (2003) 339-350, 2002 Routine observations of the Crab Nebula for a total of about 250 hrs, performed with the HEGRA stereoscopic system of 5 imaging atmospheric Cerenkov telescopes in the standard operational mode, have proven the energy threshold of the system to be 500 GeV for small zenith angles (< 20 deg).
arxiv +1 more source
Advances in High Energy Physics, Volume 2012, Issue 1, 2012., 2012 Necessary condition for β‐decay suppression of a neutron in degenerate magnetized electron gas is formulated. Based on this, it is shown that, in superstrong magnetic field, equilibrium radius of a neutron star is approximately several times smaller than without the field influence. Therefore, we can make a prediction that in short‐period pulsars, such
Vladimir V. Skobelev, C. Q. Geng
wiley +1 more source
Magnetic dissipation in the Crab Nebula [PDF]
, 2012 Magnetic dissipation is frequently invoked as a way of powering the observed emission of relativistic flows in Gamma Ray Bursts and Active Galactic Nuclei. Pulsar Wind Nebulae provide closer to home cosmic laboratories which can be used to test the hypothesis.
arxiv +1 more source
Pulsar‐Driven Jets in Supernovae, Gamma‐Ray Bursts, and the Universe
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 The bipolarity of Supernova 1987A can be understood through its very early light curve from the CTIO 0.4 m telescope and IUE FES and following speckle observations of the “Mystery Spot”. These indicate a beam/jet of light/particles, with initial collimation factors >104 and velocities >0.95 c, involving up to 10−5 M⊙ interacting with circumstellar ...
John Middleditch +1 more
wiley +1 more source
The origin of peculiar jet-torus structure in the Crab nebula [PDF]
Mon.Not.Roy.Astron.Soc. 344 (2003) L93, 2003 Recent discoveries of the intriguing ``jet-torus'' structure in the Crab Nebula and other pulsar nebulae prompted calls for re-examining of their theory. The most radical proposals involve abolishing of the MHD approximation altogether and developing of purely electromagnetic models. However, the classical MHD models of the Crab Nebula were hampered by
arxiv +1 more source
International Scholarly Research Notices, Volume 2012, Issue 1, 2012., 2012 Air shower simulations with CORSIKA6.990 code using FLUKA 2011 and QGSJET II hadron generators are performed. The simulations are carried out at high mountain observation level, namely, Chacaltaya cosmic ray station. The lateral distribution of atmospheric Cherenkov light produced by various primary particles, namely, proton, helium, oxygen, and iron ...
Alexander Mishev +4 more
wiley +1 more source
Focusing X‐Ray Optics for Astronomy
X-Ray Optics and Instrumentation, Volume 2010, Issue 1, 2010., 2010 Focusing X‐ray telescopes have been the most important factor in X‐ray astronomy’s ascent to equality with optical and radio astronomy. They are the prime tool for studying thermal emission from very high temperature regions, non‐thermal synchrotron radiation from very high energy particles in magnetic fields and inverse Compton scattering of lower ...
Paul Gorenstein, Stephen L. O′Dell
wiley +1 more source