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Fast acceleration of a CME‐related X‐ray structure in the low solar corona
Author(s) -
Alexander David,
Metcalf Thomas R.,
Nitta Nariaki V.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl013670
Subject(s) - physics , acceleration , coronal mass ejection , astrophysics , interplanetary spaceflight , solar flare , corona (planetary geology) , particle acceleration , flare , astronomy , solar wind , plasma , nuclear physics , classical mechanics , astrobiology , venus
We report on a unique observation of the early and rapid acceleration of a fast CME in the low solar corona. The coronal disturbance associated with a LASCO CME and concurrent X1.2 flare on 1998 April 23 was well‐observed by the Yohkoh Soft X‐ray Telescope. The X‐ray observations clearly show an accelerating structure, reaching 800–1100 km/s in ∼500s at a de‐projected height of only 280 Mm, indicating an acceleration well in excess of 1700 m/s 2 . The soft X‐ray observations are coincident with the onset of the CME, which ultimately attained a velocity of 1390 km/s and generated a number of interplanetary radio signatures, frequently associated with fast events. Assuming a constant acceleration, a 0 , throughout the duration of the X‐ray observations, we determine a best‐fit value of a 0 = 1756 m/s 2 , while application of a power‐law acceleration model yields a better fit to the data with a peak acceleration of ∼4865 m/s 2 within the first 280 Mm of the solar corona.