Results 61 to 70 of about 198,015 (291)
Detection of the Characteristic Pion-Decay Signature in Supernova Remnants [PDF]
Accelerated Protons Although cosmic rays were first detected a hundred years ago, their origin is still not fully understood. Comic rays are high-energy particles, mostly protons, which bombard Earth from outer space.
M. Ackermann+198 more
semanticscholar +1 more source
PROBING X-RAY ABSORPTION AND OPTICAL EXTINCTION IN THE INTERSTELLAR MEDIUM USING CHANDRA OBSERVATIONS OF SUPERNOVA REMNANTS [PDF]
We present a comprehensive study of interstellar X-ray extinction using the extensive Chandra supernova remnant (SNR) archive and use our results to refine the empirical relation between the hydrogen column density and optical extinction. In our analysis,
Dillon R. Foight+3 more
semanticscholar +1 more source
AbstractThe present structure and recent changes in Cas A are discussed. On the deepest available exposures the optical remnant of this supernova is seen to consist of an almost complete shell. The southern part of this shell is outlined by knots that have developed during the last decade.
openaire +2 more sources
Particle propagation in clumpy supernova remnants [PDF]
The presence of dense clumps in the environment where a supernova remnant expands might have a strong impact in shaping the observed hadronic gamma-ray spectrum.
Celli Silvia
doaj +1 more source
Neutrinos from Supernovas and Supernova Remnants [PDF]
Supernovae (SN) and supernova remnants (SNR) have key roles in galaxies, but their physical descriptions is still incomplete. Thus, it is of interest to study neutrino radiation to understand SN and SNR better. We will discuss: (1) The ~10 MeV thermal neutrinos that arise from core collapse SN, that were observed for SN1987A, and can be seen with ...
M.L. Costantini, Francesco Vissani
openaire +3 more sources
Grammage of cosmic rays around Galactic supernova remnants [PDF]
The residence time of cosmic rays (CRs) in the Galaxy is usually inferred from the measurement of the ratio of secondary-to-primary nuclei, for instance the boron (B)/carbon (C) ratio, which provides an estimate of the amount of matter traversed by CRs ...
M. D’Angelo, P. Blasi, E. Amato
semanticscholar +1 more source
Abstract An almost perfect round hole of CO-line emission with a diameter of 3.7 pc was found in a molecular cloud (MC) centered on G35.75−0.25 (l = 35${{^{\circ}_{.}}}$75, b = −0${{^{\circ}_{.}}}$25) at radial velocity of 28 km s−1.
openaire +4 more sources
Gamma-ray emission from young supernova remnants: Hadronic or leptonic?
The debate on the nature of the gamma-ray emission from young supernova remnants is still open. Ascribing such emission to hadronic rather than leptonic processes would provide an evidence for the acceleration of protons and nuclei, and this fact would ...
Gabici Stefano, Aharonian Felix
doaj +1 more source
A Statistical Analysis of Galactic Radio Supernova Remnants
We present a revised table of 390 Galactic radio supernova remnants (SNRs) and their basic parameters. Statistical analyses are performed on SNR diameters, ages, spectral indices, Galactic heights, and spherical symmetries.
S. Ranasinghe, D. Leahy
doaj +1 more source
Shocks and Particle Acceleration in Supernova Remnants: Observational Features
The last ten years a number of observational advances have substantially increased our knowledge of shock phenomena in supernova remnants. This progress has mainly been made possible by the recent improvements in X-ray and Gamma-ray instrumentation.
Aharonian+63 more
core +2 more sources