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Title: SUB-THz RADIATION MECHANISMS IN SOLAR FLARES

Journal Article · · Astrophysical Journal Letters
 [1]
  1. Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States)

Observations in the sub-THz range of large solar flares have revealed a mysterious spectral component increasing with frequency and hence distinct from the microwave component commonly accepted to be produced by gyrosynchrotron (GS) emission from accelerated electrons. Evidently, having a distinct sub-THz component requires either a distinct emission mechanism (compared to the GS one), or different properties of electrons and location, or both. We find, however, that the list of possible emission mechanisms is incomplete. This Letter proposes a more complete list of emission mechanisms, capable of producing a sub-THz component, both well known and new in this context, and calculates a representative set of their spectra produced by (1) free-free emission, (2) GS emission, (3) synchrotron emission from relativistic positrons/electrons, (4) diffusive radiation, and (5) Cherenkov emission. We discuss the possible role of the mechanisms in forming the sub-THz emission and emphasize their diagnostics potential for flares.

OSTI ID:
21301364
Journal Information:
Astrophysical Journal Letters, Vol. 709, Issue 2; Other Information: DOI: 10.1088/2041-8205/709/2/L127; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English