2014年3月5日 · The hadronic interpretation of the gamma-ray spectrum of W44 is viable, and supported by strong evidence. It implies a relatively large value for the average magnetic field (B > 10^2 microG) in the SNR surroundings, sign of field amplification by shock-driven turbulence.

2010年1月7日 · Our results for W44 demonstrate the capability of the Fermi LAT for morphological and spectral studies of GeV emission from Galactic SNRs, which allow us to study the escape of energetic particles from SNR shells into interstellar space, the evolution of SNR shocks during the age of the SNR, and the impact of a dense environment.

4 天之前 · W44 is a exemplar case of a sedov phase SNR emitting in gamma-rays via hadronic interactions. The presence of a cutoff below TeV energies points to questions about the acceleration mechanism and propagation models that suggest SNRs are able to produce cosmic rays with energies up to the knee of the locally observed cosmic ray spectrum.

2012年11月14日 · The remnant of the supernova explosion, which goes by the name of “SNR W44”, comprises an expanding shell of warm dust and a bubble of extremely hot gas. The dense network of filaments and clumps is part of a larger region of gas and dust, and stars are currently forming there today.

2012年10月1日 · W44 (G34.7-0.4) is one of the most studied Supernova Remnants (SNRs) because it is an ideal system to study Cosmic-Ray (CR) production, acceleration and propagation.

6 天之前 · Observations of GeV gamma-ray emission from the well-studied mixed-morphology supernova remnant (SNR) W44 by Fermi-LAT and AGILE imply that it is a site of significant cosmic ray acceleration. The spectral energy distribution (SED) derived from the GeV data suggest that the gamma-ray emission likely originates from the decay of neutral pions generated by cosmic-ray interactions. It is ...

The SNR W44 is one of the most interesting SNRs observed so far; it is a middle-aged SNR, bright at gamma-ray energies, and quite close to us. Its gamma-ray spectral index (indicative of the underlying proton/ion distribution in the hadronic model) is p ~ 3, which is in apparent contradiction with DSA models. The SNR W44 is therefore an ideal ...

1993年12月1日 · We analyze EXOSAT and Einstein Observatory X-ray spectra, an Einstein X-ray image, and a detailed VLA radio map of the SNR W44. The diffuse soft X-ray emission, which is only observed from the interior of the SNR, is shown to be largely of thermal origin.

The middle-aged supernova remnant (SNR) W44 has recently attracted attention because of its relevance regarding the origin of Galactic cosmic-rays. For the first time for a SNR, the gamma-ray missions AGILE and Fermi have established the spectral continuum below 200 MeV, which can be attributed to a neutral pion emission.

W44 (G34.7-0.4) is one of the most studied Supernova Remnants (SNRs) because it is an ideal system to study Cosmic-Ray (CR) production, acceleration and propagation.