Results 31 to 40 of about 706 (178)

Gamma-ray emission from star-forming complexes observed by MAGIC: The cases of W51 and HESS J1857+026

open access: yesEPJ Web of Conferences, 2015
Massive star-forming regions assemble a large number of young stars with remnants of stellar evolution and a very dense environment. Therefore, particles accelerated in supernova remnants and pulsar wind nebulae encounter optimal conditions for ...
Reichardt I.   +5 more
doaj   +1 more source

Proton Acceleration with Relativistic Electromagnetic Shock

open access: yesAdvanced Science, Volume 12, Issue 30, August 14, 2025.
New Ion Acceleration Mechanism! A novel cosmic‐ray proton acceleration mechanism is proposed, where relativistic electromagnetic shocks accelerate protons transversely. Hamiltonian analysis yields a scaling law linking the proton energy to the minimum longitudinal thickness of the shock.
Ting Xiao   +5 more
wiley   +1 more source

Pulsar‐Driven Jets in Supernovae, Gamma‐Ray Bursts, and the Universe

open access: yesAdvances 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

Beyond Accretion Limits: The Rise of Pulsating Gems

open access: yesAstronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The discovery of several ultraluminous X‐ray sources exhibiting fast and rapidly evolving X‐ray pulsations unequivocally associates these sources with accreting neutron stars orbiting relatively massive companion stars (> 8M ⊙$$ {}_{\odot } $$).
Gian Luca Israel   +26 more
wiley   +1 more source

Focusing X‐Ray Optics for Astronomy

open access: yesX-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

Heavy Elements and Electromagnetic Transients from Neutron Star Mergers

open access: yesAnnalen der Physik, Volume 536, Issue 2, February 2024.
Astro‐(physics) has made major leaps forward through the combined information provided by both gravitational waves and electromagnetic emission from the first detected neutron star merger event. This review provides an up‐to‐date overview of today's understanding of neutron star mergers and their electromagnetic emission and it discusses possible ...
Stephan Rosswog, Oleg Korobkin
wiley   +1 more source

The Dark Matter Annihilation Signal from Dwarf Galaxies and Subhalos

open access: yesAdvances 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

Spatial Variations and Breaks in the Optical–Near-infrared Spectra of the Pulsar and Pulsar Wind Nebula in Supernova Remnant 0540–69.3

open access: yesThe Astrophysical Journal
The supernova remnant (SNR) 0540–69.3, twin of the Crab Nebula, offers an excellent opportunity to study the continuum emission from a young pulsar and pulsar wind nebula (PWN). We present observations taken with the Very Large Telescope instruments MUSE
L. Tenhu   +6 more
doaj   +1 more source

Laue Gamma‐Ray Lenses for Space Astrophysics: Status and Prospects

open access: yesX-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

HAWC, VERITAS, Fermi-LAT, and XMM-Newton Follow-up Observations of the Unidentified Ultra-high-energy Gamma-Ray Source LHAASO J2108+5157

open access: yesThe Astrophysical Journal
We report observations of the ultra-high-energy gamma-ray source LHAASO J2108+5157, utilizing VERITAS, HAWC, Fermi-LAT, and XMM-Newton. VERITAS has collected ∼40 hr of data that we used to set ULs to the emission above 200 GeV.
C. B. Adams   +145 more
doaj   +1 more source

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