Solar Type Examples

Reid Vilmer Kontar 2014 - Type III starting frequencies and hard X-rays

I take note of Reid, Hamish A. S.; Vilmer, Nicole; Kontar, Eduard P., 2014
   
"The Low-High-Low Trend of Type III Radio Burst Starting Frequencies and Solar Flare Hard X-rays"

http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1403.1839

Abstract: "Using simultaneous X-ray and radio observations from solar flares, we investigate the link between the type III radio burst starting frequency and hard X-ray spectral index. For a proportion of events the relation derived between the starting height (frequency) of type III radio bursts and the electron beam velocity spectral index (deduced from X-rays) is used to infer the spatial properties (height and size) of the electron beam acceleration region. Both quantities can be related to the distance travelled before an electron beam becomes unstable to Langmuir waves. To obtain a list of suitable events we considered the RHESSI catalogue of X-ray flares and the Phoenix 2 catalogue of type III radio bursts. From the 200 events that showed both type III and X-ray signatures, we selected 30 events which had simultaneous emission in both wavelengths, good signal to noise in the X-ray domain and > 20 seconds duration. We find that > 50 % of the selected events show a good correlation between the starting frequencies of the groups of type III bursts and the hard X-ray spectral indices. A low-high-low trend for the starting frequency of type III bursts is frequently observed. Assuming a background electron density model and the thick target approximation for X-ray observations, this leads to a correlation between starting heights of the type III emission and the beam electron spectral index. Using this correlation we infer the altitude and vertical extents of the flare acceleration regions. We find heights from 183 Mm down to 25 Mm while the sizes range from 13 Mm to 2 Mm. These values agree with previous work that places an extended flare acceleration region high in the corona. We analyse the assumptions required and explore possible extensions to our assumed model. We discuss these results with respect to the acceleration heights and sizes derived from X-ray observations alone."

Li Sun Wang Dai 2013, "Coronal magnetic topology and the production of solar impulsive energetic electrons"

I refer to: Li Sun Wang Dai 2013, "Coronal magnetic topology and the production of solar impulsive energetic electrons"

http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1307.4494

Abstract
"We investigate two candidate solar sources or active regions (ARs) in association with a solar impulsive energetic electron (SIEE) event on 2002 October 20. The solar particle release (SPR) times of SIEEs are derived by using their velocity dispersion with consideration of the instrumental effect. It is found that there are double electron injections at the Sun. The low-energy (< 13 keV) electron injection coincides with a C6.6 flare in AR10154 and is accompanied with prominent type III radio bursts rather than a stronger M1.8 flare in AR10160. The M1.8 flare produces, however, faint type III radio bursts. Electrons of ~25 to ~300 keV are released ~9 min later when a jet-like CME travels to ~2.6 solar radii. We further examine the coronal magnetic configurations above the two ARs based on the potential field source surface (PFSS) model. It is found that open field lines, rooted in AR10154 and well connected to the Earth, provide escaping channels for energetic electrons. Only a small portion of magnetic fields are opened above AR10160, being responsible for the faint type III radio bursts. These lines are, however, not well connected, making it impossible for SIEEs detection by near-Earth spacecraft. The results appear to establish a physical link between coronal magnetic topology, formation of type III radio bursts, and production of SIEEs."

Sun 131230, M3.1 and 10 C flares in AR 11936, 10 selected events

Many thanks to the Taxpayers of France, the Nancay Decametric Array Team at the Nancay Radio Astronomy Station of Paris Observatory, Trinity College Dublin Astrophysics Group, and NASA SDO HMI Magnetograph Team.

Stereo triangulation and beaming characteristics of Solar Type III Radio Bursts

A refer to Reiner et al. 2007:

http://adsabs.harvard.edu/abs/2007AGUFMSH42A..02R

Below, I copy figures 1 and 4 from the paper. The authors discus the "intrinsic physical characteristics of these radio sources, such as the brightness temperatures and beaming characteristics, at different observing radio frequencies".

A discussion of type III radiation associated with the X3.9 flare on 031103

I refer to:

Chen, Qingrong; Petrosian, Vahé 2012, Stanford University:


http://adsabs.harvard.edu/abs/2012ApJ...748...33C

The authors briefly discuss Type III radiation associated with the flare.

Abstract: "...Finally, we show that the electrons producing the upper coronal HXR source may very likely be responsible for the type III radio bursts at the decimetric/metric wavelength observed during the impulsive phase of this flare..."

Extreme Ultra Violet jets, type III bursts, and sunspot waves

I refer to:
Innes Cameron Solanki 2011, Max-Planck Institut für Sonnensystemforschung:

http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1106.3417

The authors discuss a correlation of quasi periodic EUV jets observed on 100803 on Solar Dynamics Observatory 211 angstrom images and type III bursts observed in WIND WAVES dynamic spectra, 20 kHz to 13.6 MHz band. The EUV jets correlate with brightening at a small site on the edge of the sunspot umbra, and the brightening with 3-min sunspot intensity oscillations.

"...Conclusions: Active region EUV/X-ray jets and interplanetary electron streams originate on the edge of the sunspot umbra. They form along a current sheet between the sunspot open field and closed field connecting to underlying satellite flux. Sunspot running penumbral waves cause roughly 3-min jet footpoint brightening. The relationship between the waves and jets is less clear..."

Brief review of Li Cairns Robinson 2010, "Imprints of coronal temperature disturbances on type III bursts", University of Sydney School of Physics

I refer to:
http://adsabs.harvard.edu/abs/2010A%26A...510L...6L

and references at:
http://adsabs.harvard.edu/cgi-bin/nph-ref_query?bibcode=2010A%26A...510L...6L&refs=REFERENCES&db_key=AST

This paper describes the first simulations to study the effects on coronal type IIIs of spatially localized disturbances in electron or ion temperatures.