Comparison of 30 THz impulsive burst time development to microwaves, H-alpha, EUV, and GOES soft X-rays

TL;DR

This study compares the timing and structure of a 30 THz impulsive solar burst with emissions in microwaves, H-alpha, EUV, and X-rays, revealing complex relationships and possible emission mechanisms.

Contribution

It provides the first detailed comparison of 30 THz burst timing with other wavelengths, highlighting discrepancies and suggesting a common lower chromospheric origin.

Findings

30 THz emission shows timing discrepancies with microwaves and X-rays.

Impulsive phase emissions likely originate from a common low chromospheric site.

30 THz burst may be due to nonthermal processes or rapid thermal response.

Abstract

The recent discovery of impulsive solar burst emission in the 30 THz band is raising new interpretation challenges. One event associated with a GOES M2 class flare has been observed simultaneously in microwaves, H-alpha, EUV, and soft X-ray bands. Although these new observations confirm some features found in the two prior known events, they exhibit time profile structure discrepancies between 30 THz, microwaves, and hard X-rays (as inferred from the Neupert effect). These results suggest a more complex relationship between 30 THz emission and radiation produced at other wavelength ranges. The multiple frequency emissions in the impulsive phase are likely to be produced at a common flaring site lower in the chromosphere. The 30 THz burst emission may be either part of a nonthermal radiation mechanism or due to the rapid thermal response to a beam of high-energy particles bombarding the dense solar atmosphere.