Fermi-LAT Detects Gamma-Ray Emission from Supernova Remnant B0453-685 in Large Magellanic Cloud
Astronomers have detected faint gamma-ray emission from the composite supernova remnant B0453-685 in the Large Magellanic Cloud using the Fermi-LAT space telescope, identifying it as only the second extragalactic pulsar wind nebula (PWN) discovered in the MeV-GeV band. The emission, spanning 300 MeV to 2 TeV, is best explained by an evolved PWN approximately 14,000 years old that has been disrupted by the return of the supernova remnant's reverse shock. The finding has implications for understanding how PWNe contribute to the production of cosmic rays.
Using data from the Fermi Large Area Telescope (Fermi-LAT), researchers have identified point-like gamma-ray emission at the location of composite supernova remnant B0453-685 in the Large Magellanic Cloud, making it only the second extragalactic PWN detected in the MeV-GeV energy range. A multi-wavelength analysis ruled out the supernova remnant shell itself as the source of the gamma-ray emission, pointing instead to a pulsar wind nebula origin. Semi-analytic radiative evolutionary modeling suggests the PWN is highly evolved, with a characteristic age of roughly 14,000 years, and has been significantly affected by the reverse shock of the surrounding SNR. The models also indicate a possible substantial pulsar contribution to the emission below 5 GeV. The study highlights the importance of PWNe as potential sources of cosmic rays, though the authors note that better constraints on the synchrotron cut-off frequency are needed to fully characterize the underlying particle population and acceleration mechanisms. The results were published in the Proceedings of Science for the Multifrequency Behaviour of High Energy Cosmic Sources XIV conference in 2023.
What's missing
The study acknowledges that constraints on the synchrotron cut-off frequency are lacking, which limits the accuracy of the particle property characterization. The pulsar powering the PWN has not been directly detected or confirmed, leaving the pulsar component below 5 GeV as a model inference rather than an observational result.
What different sources said
- arXiv astro-phCenter
Fermi-LAT Gamma-ray Emission Discovered from the Composite Supernova Remnant B0453-685 in the Large Magellanic Cloud
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