Hercules A

Hercules A
Radio-Optical View of the Galaxy Hercules A - Many thanks to: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)

Monday, May 23, 2011

Correlation of type III, electron spike, and ultraviolet jet events on 100222

Klassen with Gomez-Herrero and Heber, 2011:
study STEREO A data from the WAVES radio telescope, the SEPT solar electron proton telescope, and SECCHI EUV images.

I quote from the abstract:
"...Each of the four events was associated with a type III radio burst and a narrow EUV jet. All the events show nearly symmetric "spike"-like time profiles with very short durations ~ 5 min. The estimated electron injection time for each individual event shows a small time delay between the electron spike and the corresponding type III radio emission and a close coincidence with an EUV jet. These observations reveal the existence of spike-like electron events showing nearly "scatter-free" propagation from the Sun to STEREO-A. From the time coincidence we infer that the mildly relativistic electrons are accelerated at the same time and at the same location as the accompanying type III emitting electrons and coronal EUV jets. The characteristics of the spikes reflect the injection and acceleration profiles in the corona rather than interplanetary propagation effects..."

This is the summary of their main results:

i) A sequence of four spikes occur during a short time interval of 100 min and show almost symmetric time profiles with durations below 5 min.

ii) All electron spikes were temporally coincident with type III radio bursts and very collimated recurrent EUV coronal jets, appearing at the same location and showing the same trajectory.

iii) The sharp spike-like profiles and the observed durations between three and five minutes set an upper limit on the duration of the electron injection into the interplanetary medium of ≤1 min, comparable with the durations of type III radio bursts.

The illustration shows figures 1 and 2 from the paper.