SPECTROSCOPIC OBSERVATIONS OF AN EVOLVING FLARE RIBBON SUBSTRUCTURE SUGGESTING ORIGIN IN CURRENT SHEET WAVES

Journal Article · Tue Sep 01 00:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/810/1/4· OSTI ID:22525539

Brannon, S. R.; Longcope, D. W.; Qiu, J. ^[1]

---

1. Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

We present imaging and spectroscopic observations from the Interface Region Imaging Spectrograph of the evolution of the flare ribbon in the SOL2014-04-18T13:03 M-class flare event, at high spatial resolution and time cadence. These observations reveal small-scale substructure within the ribbon, which manifests as coherent quasi-periodic oscillations in both position and Doppler velocities. We consider various alternative explanations for these oscillations, including modulation of chromospheric evaporation flows. Among these, we find the best support for some form of wave localized to the coronal current sheet, such as a tearing mode or Kelvin–Helmholtz instability.

• OSTI ID: 22525539
• Journal Information: Astrophysical Journal, Vol. 810, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CHROMOSPHERE
EVAPORATION
HELMHOLTZ INSTABILITY
MODULATION
OSCILLATIONS
PERIODICITY
SHEETS
SOLAR CORONA
SPATIAL RESOLUTION
STAR EVOLUTION
SUN
TEARING INSTABILITY
VELOCITY