scholarly journals An extended source of GeV gamma rays coincident with the supernova remnant HB 21

2012 ◽  
Author(s):  
Ignasi Reichardt ◽  
Emma De Oña-Wilhelmi ◽  
Javier Rico ◽  
Rui-zhi Yang
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant ◽  
Extended Source

scholarly journals An extended source of GeV gamma rays coincident with the supernova remnant HB 21

2012 ◽  
Vol 546 ◽  
pp. A21 ◽  
Author(s):  
I. Reichardt ◽  
E. de Oña-Wilhelmi ◽  
J. Rico ◽  
R. Yang
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant ◽  
Extended Source

scholarly journals A source of gamma rays coincident with the shell of the supernova remnant CTB 80

2021 ◽  
Vol 502 (1) ◽  
pp. 472-477
Author(s):  
M Araya ◽  
C Herrera
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Large Area ◽  
Extended Source ◽  
X Ray ◽  
Extended Radio ◽  
High Energy Emission

ABSTRACT CTB 80 (G69.0+2.7) is a relatively old (50–80 kyr) supernova remnant (SNR) with a complex radio morphology showing three extended radio arms and a radio and X-ray nebula near the location of the pulsar PSR B1951+32. We report on a study of the GeV emission in the region of CTB 80 with Fermi-Large Area Telescope data. An extended source with a size of 1.3°, matching the size of the infrared shell associated to the SNR, was discovered. The GeV emission, detected up to an energy of ∼20 GeV, is more significant at the location of the northern radio arm where previous observations imply that the SNR shock is interacting with ambient material. Both hadronic and leptonic scenarios can reproduce the multiwavelength data reasonably well. The hadronic cosmic ray energy density required is considerably larger than the local Galactic value and the gamma-ray leptonic emission is mainly due to bremsstrahlung interactions. We conclude that GeV particles are still trapped or accelerated by the SNR producing the observed high-energy emission when interacting with ambient material.

scholarly journals G279.0+1.1: a new extended source of high-energy gamma-rays

2020 ◽  
Vol 492 (4) ◽  
pp. 5980-5986
Author(s):  
M Araya
Keyword(s):  
Spectral Index ◽  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
Particle Spectrum ◽  
Large Area ◽  
Extended Source ◽  
The North ◽  
Energy Gamma ◽  
High Energy Emission

ABSTRACT G279.0+1.1 is a supernova remnant (SNR) with poorly known parameters, first detected as a dim radio source and classified as an evolved system. An analysis of data from the Fermi-Large Area Telescope (LAT) revealing for the first time an extended source of gamma-rays in the region is presented. The diameter of the GeV region found is ${\sim} 2{^{\circ}_{.}}8$, larger than the latest estimate of the SNR size from radio data. The gamma-ray emission covers most of the known shell and extends further to the north and east of the bulk of the radio emission. The photon spectrum in the 0.5–500 GeV range can be described by a simple power law, $\frac{\mathrm{ d}N}{\mathrm{ d}E} \propto E^{-\Gamma }$, with a spectral index of Γ = 1.86 ± 0.03stat ± 0.06sys. In the leptonic scenario, a steep particle spectrum is required and a distance lower than the previously estimated value of 3 kpc is favoured. The possibility that the high-energy emission results from electrons that already escaped the SNR is also investigated. A hadronic scenario for the gamma-rays yields a particle spectral index of ∼2.0 and no significant constraints on the distance. The production of gamma-rays in old SNRs is discussed. More observations of this source are encouraged to probe the true extent of the shell and its age.

scholarly journals CANGAROO‐III Search for Gamma Rays from Kepler’s Supernova Remnant

2008 ◽  
Vol 683 (1) ◽  
pp. 383-388 ◽  
Author(s):  
R. Enomoto ◽  
Y. Higashi ◽  
T. Yoshida ◽  
T. Tanimori ◽  
G. V. Bicknell ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant

scholarly journals Radio Observations of the Supernova Remnant CTB109 (G109.2–1.0)

1983 ◽  
Vol 101 ◽  
pp. 455-458
Author(s):  
V. A. Hughes ◽  
R. H. Harten ◽  
C. Costain ◽  
L. Nelson ◽  
M. R. Viner
Keyword(s):  
Antenna Arrays ◽  
Supernova Remnant ◽  
Galactic Plane ◽  
Radio Observations ◽  
Extended Source ◽  
Radio Observatory ◽  
X Ray ◽  
Close Proximity ◽  
Strong Source ◽  
Cas A

The supernova remnant G109.2–1.0 was discovered at λ49cm by Hughes, Harten and van den Bergh (1981) during a survey of part of the Galactic plane. The northern part of it had been detected previously as the non-thermal radio source CTB109 by Wilson and Bolton (1960), and by Raghava Roa et al (1965), but the extended low brightness of the source and its close proximity to the very strong source Cas A, from which it is separated by ∼5′, excluded it from any further detailed study. It was discovered independently at X-ray wavelengths by Gregory and Fahlman (1980). Recently, the original WSRT radio observations have been found to be in error as a result of applying the CLEAN procedure to an extended source, and since the object appears to contain an X-ray pulsar (Fahlman and Gregory, 1981), it was decided to carry out a more detailed and extensive mapping of the remmant using different antenna arrays and frequencies. This paper describes the results obtained at λ49cm and λ21cm using the Westerbork Synthesis Radio Telescope (WSRT), at λ21cm using the aperture synthesis array at the Dominion Radio Astrophysical Observatory (DRAO) and at λ4.6cm using the 46m telescope of the Algonquin Radio Observatory (ARO). Thus, data has been obtained from three completely independent telescopes, using completely independent data reduction systems. Of importance is the fact that not only have wavelengths been chosen such that the larger dimensions of the array give a reasonable angular resolution of ≤1′, but also that the smallest spacing enables the larger angular dimensions of the remnant to be observed. This paper presents some of the results and a brief interpretation.

scholarly journals Particle propagation in clumpy supernova remnants

2019 ◽  
Vol 209 ◽  
pp. 01033
Author(s):  
Silvia Celli
Keyword(s):  
Gamma Rays ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
Numerical Study ◽  
Background Plasma ◽  
Strong Impact ◽  
Propagation Effects ◽  
Particle Propagation

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. A detailed numerical study about the penetration of relativistic protons into clumps which are engulfed by a supernova remnant shock is here presented, taking into account the magneto-hydrodynamical properties of the background plasma. This has strong implications for the formation of the spectrum of hadronic gamma rays, which does not reflect anymore the acceleration spectrum of protons, resulting substantially modified by propagation effects. A hadronic scenario including dense clumps inside the remnant shell is shown to adequately reproduce the broadband gamma-ray spectrum of the Galactic supernova remnant RX J1713-3946.7 from GeV to TeV energies.

scholarly journals Predictions for gamma-rays from clouds associated with supernova remnant PeVatrons

2021 ◽  
Author(s):  
Alison Mitchell ◽  
Gavin Rowell ◽  
Silvia Celli ◽  
Sabrina Einecke
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant

scholarly journals The X-ray synchrotron nebula around PSR 1509-58

1996 ◽  
Vol 160 ◽  
pp. 351-352
Author(s):  
K.T.S. Brazier
Keyword(s):  
Gamma Rays ◽  
Supernova Remnant ◽  
X Rays ◽  
X Ray ◽  
Synchrotron Nebula

PSR 1509-58 is one of the youngest and most powerful pulsars known and is visible not only in soft X-rays, but in gamma-rays. Observations of its supernova remnant (MSH 15-52) offer a rare chance to study such a young pulsar and to explore its surroundings, which in X-rays include the pulsar’s 10×6 arcmin X-ray synchrotron nebula and the peculiar, filamentary optical nebula, RCW 89, that sits on the limb of MSH 15-52 (Seward & Harnden 1982, Seward et al. 1983). This paper will concentrate on the morphology of the synchrotron nebula.

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