Planck intermediate results: XXXI. Microwave survey of Galactic supernova remnants

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2016-02-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
1-21
Series
ASTRONOMY AND ASTROPHYSICS, Volume 586
Abstract
The all-sky Planck survey in 9 frequency bands was used to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for microwave emission. In only one case, IC 443, is there high-frequency emission clearly from dust associated with the supernova remnant. In all cases, the low-frequency emission is from synchrotron radiation. As predicted for a population of relativistic particles with energy distribution that extends continuously to high energies, a single power law is evident for many sources, including the Crab and PKS 1209-51/52. A decrease in flux density relative to the extrapolation of radio emission is evident in several sources. Their spectral energy distributions can be approximated as broken power laws, Sν ∝ ν-α, with the spectral index, α, increasing by 0.5-1 above a break frequency in the range 10-60 GHz. The break could be due to synchrotron losses.
Description
Keywords
cosmic rays, ISM: supernova remnants, radio continuum: ISM
Other note
Citation
Planck Collaboration 2016, ' Planck intermediate results : XXXI. Microwave survey of Galactic supernova remnants ', Astronomy and Astrophysics, vol. 586, A134, pp. 1-21 . https://doi.org/10.1051/0004-6361/201425022