Results 21 to 30 of about 12,273 (135)
The effects of magnetic field, age, and intrinsic luminosity on Crab-like pulsar wind nebulae [PDF]
, 2013 We investigate the time-dependent behavior of Crab-like pulsar wind nebulae (PWNe) generating a set of models using 4 different initial spin-down luminosities ($L_0 =\{1,0.1,0.01,0.001\} \times L_{0, {\rm Crab}}$), 8 values of magnetic fraction ($\eta =$ 0.001, 0.01, 0.03, 0.1, 0.5, 0.9, 0.99, and 0.999, i.e., from fully particle dominated to fully ...
arxiv +1 more source
The Dark Matter Annihilation Signal from Dwarf Galaxies and Subhalos
Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 Dark Matter annihilation holds great potential for directly probing the clumpiness of the Galactic halo that is one of the key predictions of the Cold Dark Matter paradigm of hierarchical structure formation. Here we review the γ‐ray signal arising from dark matter annihilation in the centers of Galactic subhalos.
Michael Kuhlen, Andrey V. Kravtsov
wiley +1 more source
Laue Gamma‐Ray Lenses for Space Astrophysics: Status and Prospects
X-Ray Optics and Instrumentation, Volume 2010, Issue 1, 2010., 2010 We review feasibility studies, technological developments, and the astrophysical prospects for Laue lenses devoted to hard X‐/gamma‐ray astronomy observations.
Filippo Frontera +2 more
wiley +1 more source
On the origin of the torus and jet-like structures in the centre of Crab Nebula [PDF]
Mon.Not.Roy.Astron.Soc. 336 (2002) L53, 2002 The formation of the toroidal and jet-like structures in the central part of the Crab Nebula is explained in the framework of Kennel & Coroniti theory. The only new element introduced by us in this theory is the initial anisotropy of the energy flux in the wind.
arxiv +1 more source
Geophysical Research Letters, Volume 51, Issue 20, 28 October 2024.Abstract We present X‐ray observations of the upper atmospheric density disturbance caused by the explosive eruption of the Hunga Tonga‐Hunga Ha'apai (HTHH) volcano on 15 January 2022. From 14 January to 16 January, the Chinese X‐ray astronomy satellite, Insight‐HXMT, was observing the supernova remnant Cassiopeia A.
Satoru Katsuda +16 more
wiley +1 more source
High Energy emission from Crab Nebula [PDF]
arXiv, 2020 Flaring episodes from Crab Nebula have been observed. A new mechanism of emission is explored. Particles in Crab pulsar are accelerated to multiple Tev energies, by some mechanisms, described in the paper and they are the reason of observed emission. We argue, that after accelerating to high energies, they may maintain the force-free regime - moving ...
arxiv
The Radio Spectral Index of the Crab Nebula [PDF]
, 1997 We present the results of a new, comprehensive investigation of the radio spectral index of the Crab Nebula supernova remnant. New data at 74 MHz are combined with data at 327 MHz, 1.5 GHz and 5 GHz. In contrast to previous claims, little spatial variation in the spectral index is seen.
arxiv +1 more source
On the variability of the GeV and multi-TeV gamma-ray emission from the Crab Nebula [PDF]
2011 MNRAS.414.2229B, 2010 Recently the AGILE $\gamma$-ray telescope has reported the enhanced $\gamma$-ray emission above 100 MeV from the direction of the Crab Nebula during a period of a few days. This intriguing observation has been confirmed by the Fermi-LAT telescope. This emission does not show evidences of pulsations with the Crab pulsar.
arxiv +1 more source
The variable Crab Nebula [PDF]
arXiv, 2011 The remarkable Crab Nebula is powered by an energetic pulsar whose relativistic wind interacts with the inner parts of the Supernova Remnant SN1054. Despite low-intensity optical and X-ray variations in the inner Nebula, the Crab has been considered until now substantially stable at X-ray and gamma-ray energies.
arxiv
I. Inverse Compton origin of pulsar γ-ray emission. II. Reconnection model of Crab flares [PDF]
, 2013 I. There is growing evidence that pulsars' high energy emission is generated via Inverse Compton mechanism. II. The particles producing Crab flares, and possibly most of the Crab Nebula's high energy emission, are accelerated via reconnection events, and not at shock via Fermi mechanisms.
arxiv +1 more source