LMC N132D: A mature supernova remnant with a power-law gamma-ray spectrum extending beyond 8 TeV

ABSTRACT We present the results from the Suzaku X-ray Imaging Spectrometer observation of the mixed-morphology supernova remnant (SNR) HB9 (G160.9+2.6). We discovered recombining plasma (RP) in the western Suzaku observation region and the spectra here are well described by a model having collisional ionization equilibrium (CIE) and RP components. On the other hand, the X-ray spectra from the eastern Suzaku observation region are best reproduced by the CIE and non-equilibrium ionization model. We discuss possible scenarios to explain the origin of the RP emission based on the observational properties and concluded that the rarefaction scenario is a possible explanation for the existence of RP. In addition, the gamma-ray emission morphology and spectrum within the energy range of 0.2–300 GeV are investigated using 10 yr of data from the Fermi Large Area Telescope (LAT). The gamma-ray morphology of HB9 is best described by the spatial template of radio continuum emission. The spectrum is well fit to a log-parabola function and its detection significance was found to be 25σ. Moreover, a new gamma-ray point source located just outside the south-east region of the SNR’s shell was detected with a significance of 6σ. We also investigated the archival H i and CO data and detected an expanding shell structure in the velocity range of $-10.5$ and $+1.8$ km s−1 that is coinciding with a region of gamma-ray enhancement at the southern rim of the HB9 shell.

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CTA 1 supernova remnant: A high energy gamma-ray source?

10.1063/1.54092 ◽

1997 ◽

Author(s):

D. Bhattacharya ◽

A. Akyüz ◽

G. Case ◽

D. Dixon ◽

A. Zych

Keyword(s):

Supernova Remnant ◽

Gamma Ray ◽

High Energy ◽

High Energy Gamma ◽

Energy Gamma

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Revealing G150.3+4.5 as a dynamically young supernova remnant with gamma-ray data

10.22323/1.395.0623 ◽

2021 ◽

Author(s):

Justine Devin

Keyword(s):

Supernova Remnant ◽

Gamma Ray ◽

Young Supernova Remnant

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Detection of the Geminga pulsar with MAGIC hints at a power-law tail emission beyond 15 GeV

Astronomy and Astrophysics ◽

10.1051/0004-6361/202039131 ◽

2020 ◽

Vol 643 ◽

pp. L14

Author(s):

◽

V. A. Acciari ◽

S. Ansoldi ◽

L. A. Antonelli ◽

A. Arbet Engels ◽

...

Keyword(s):

Energy Range ◽

Power Law ◽

Gamma Ray ◽

Low Energy ◽

Significance Level ◽

Inverse Compton Scattering ◽

Curvature Radiation ◽

Sensitivity Range ◽

Inverse Compton ◽

First Time

We report the detection of pulsed gamma-ray emission from the Geminga pulsar (PSR J0633+1746) between 15 GeV and 75 GeV. This is the first time a middle-aged pulsar has been detected up to these energies. Observations were carried out with the MAGIC telescopes between 2017 and 2019 using the low-energy threshold Sum-Trigger-II system. After quality selection cuts, ∼80 h of observational data were used for this analysis. To compare with the emission at lower energies below the sensitivity range of MAGIC, 11 years of Fermi-LAT data above 100 MeV were also analysed. From the two pulses per rotation seen by Fermi-LAT, only the second one, P2, is detected in the MAGIC energy range, with a significance of 6.3σ. The spectrum measured by MAGIC is well-represented by a simple power law of spectral index Γ = 5.62 ± 0.54, which smoothly extends the Fermi-LAT spectrum. A joint fit to MAGIC and Fermi-LAT data rules out the existence of a sub-exponential cut-off in the combined energy range at the 3.6σ significance level. The power-law tail emission detected by MAGIC is interpreted as the transition from curvature radiation to Inverse Compton Scattering of particles accelerated in the northern outer gap.

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Fermi-LAT and WMAP observations of the supernova remnant Puppis A

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313009617 ◽

2013 ◽

Vol 9 (S296) ◽

pp. 295-299

Author(s):

Marie-Hélène Grondin ◽

John W. Hewitt ◽

Marianne Lemoine-Goumard ◽

Thierry Reposeur ◽

Keyword(s):

Supernova Remnants ◽

Supernova Remnant ◽

Gamma Ray ◽

High Energy ◽

Radio Spectrum ◽

Wilkinson Microwave Anisotropy Probe ◽

Large Area ◽

X Ray ◽

Inverse Compton Scattering ◽

Γ Ray

AbstractThe supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in γ-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The γ-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its γ-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and γ-ray domains are described in detail, as well as the possible origins of the high energy γ-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).

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