109 research outputs found
Study of flare energy release using events with numerous type III-like bursts in microwaves
The analysis of narrowband drifting of type III-like structures in radio
bursts dynamic spectra allows to obtain unique information about primary energy
release mechanisms in solar flares. The SSRT spatially resolved images and a
high spectral and temporal resolution allow direct determination not only the
positions of its sources but also the exciter velocities along the flare loop.
Practically, such measurements are possible during some special time intervals
when the SSRT (about 5.7 GHz) is observing the flare region in two high-order
fringes; thus, two 1D scans are recorded simultaneously at two frequency bands.
The analysis of type III-like bursts recorded during the flare 14 Apr 2002 is
presented. Using-muliwavelength radio observations recorded by SSRT, SBRS,
NoRP, RSTN we study an event with series of several tens of drifting microwave
pulses with drift rates in the range from -7 to 13 GHz/s. The sources of the
fast-drifting bursts were located near the top of the flare loop in a volume of
a few Mm in size. The slow drift of the exciters along the flare loop suggests
a high pitch-anisotropy of the emitting electrons.Comment: 16 pages, 6 figures, Solar Physics, in press, 201
An Observational Overview of Solar Flares
We present an overview of solar flares and associated phenomena, drawing upon
a wide range of observational data primarily from the RHESSI era. Following an
introductory discussion and overview of the status of observational
capabilities, the article is split into topical sections which deal with
different areas of flare phenomena (footpoints and ribbons, coronal sources,
relationship to coronal mass ejections) and their interconnections. We also
discuss flare soft X-ray spectroscopy and the energetics of the process. The
emphasis is to describe the observations from multiple points of view, while
bearing in mind the models that link them to each other and to theory. The
present theoretical and observational understanding of solar flares is far from
complete, so we conclude with a brief discussion of models, and a list of
missing but important observations.Comment: This is an article for a monograph on the physics of solar flares,
inspired by RHESSI observations. The individual articles are to appear in
Space Science Reviews (2011
- …