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Title: HARD X-RAY IMAGING OF INDIVIDUAL SPECTRAL COMPONENTS IN SOLAR FLARES

We present a new analytical technique, combining Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) high-resolution imaging and spectroscopic observations, to visualize solar flare emission as a function of spectral component (e.g., isothermal temperature) rather than energy. This computationally inexpensive technique is applicable to all spatially invariant spectral forms and is useful for visualizing spectroscopically determined individual sources and placing them in context, e.g., comparing multiple isothermal sources with nonthermal emission locations. For example, while extreme ultraviolet images can usually be closely identified with narrow temperature ranges, due to the emission being primarily from spectral lines of specific ion species, X-ray images are dominated by continuum emission and therefore have a broad temperature response, making it difficult to identify sources of specific temperatures regardless of the energy band of the image. We combine RHESSI calibrated X-ray visibilities with spatially integrated spectral models including multiple isothermal components to effectively isolate the individual thermal sources from the combined emission and image them separately. We apply this technique to the 2002 July 23 X4.8 event studied in prior works, and image for the first time the super-hot and cooler thermal sources independently. The super-hot source is farther from the footpoints and more elongatedmore » throughout the impulsive phase, consistent with an in situ heating mechanism for the super-hot plasma.« less
Authors:
 [1] ;  [2] ; ;  [3]
  1. Southwest Research Institute, Boulder, CO 80302 (United States)
  2. Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  3. Space Sciences Laboratory University of California, Berkeley, CA 94720 (United States)
Publication Date:
OSTI Identifier:
22518889
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 811; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; DATA ANALYSIS; EXTREME ULTRAVIOLET RADIATION; GAMMA RADIATION; HARD X RADIATION; HEATING; HOT PLASMA; IMAGES; RESOLUTION; SOLAR FLARES; SUN