Temporal Evolution of Multiple Evaporating Ribbon Sources in a Solar Flare

Journal
Date Issued
2015
Author(s)
Graham, D. R.
•
DOI
Description
This research has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 606862 (F-CHROMA).
Abstract
We present new results from the Interface Region Imaging Spectrograph (IRIS) showing the dynamic evolution of chromospheric evaporation and condensation in a flare ribbon, with the highest temporal and spatial resolution to date. IRIS observed the entire impulsive phase of the X-class flare SOL2014-09-10T17:45 using a 9.4 s cadence “sit-and-stare” mode. As the ribbon brightened successively at new positions along the slit, a unique impulsive phase evolution was observed for many tens of individual pixels in both coronal and chromospheric lines. Each activation of a new footpoint displays the same initial coronal upflows of up to ∼300 km s-1 and chromospheric downflows up to 40 km s-1. Although the coronal flows can be delayed by over 1 minute with respect to those in the chromosphere, the temporal evolution of flows is strikingly similar between all pixels and consistent with predictions from hydrodynamic flare models. Given the large sample of independent footpoints, we conclude that each flaring pixel can be considered a prototypical, “elementary” flare kernel.
Volume
807
Issue
2
Start page
L22
Uri
Url
Issn Identifier
2041-8205
Ads BibCode
2015ApJ...807L..22G
Rights
open.access
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