FIRST THREE-DIMENSIONAL RECONSTRUCTIONS OF CORONAL LOOPS WITH THE STEREO A+B SPACECRAFT. III. INSTANT STEREOSCOPIC TOMOGRAPHY OF ACTIVE REGIONS

Journal Article · Fri Apr 10 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/695/1/12; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21296272

Aschwanden, Markus J; Wuelser, Jean-Pierre; Nitta, Nariaki V; Lemen, James R; Sandman, Anne ^[1]

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1. Lockheed Martin Advanced Technology Center, Solar and Astrophysics Laboratory, Org. ADBS, Bldg.252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)

Here we develop a novel three-dimensional (3D) reconstruction method of the coronal plasma of an active region by combining stereoscopic triangulation of loops with density and temperature modeling of coronal loops with a filling factor equivalent to tomographic volume rendering. Because this method requires only a stereoscopic image pair in multiple temperature filters, which are sampled within {approx}1 minute with the recent STEREO/EUVI instrument, this method is about four orders of magnitude faster than conventional solar rotation-based tomography. We reconstruct the 3D density and temperature distribution of active region NOAA 10955 by stereoscopic triangulation of 70 loops, which are used as a skeleton for a 3D field interpolation of some 7000 loop components, leading to a 3D model that reproduces the observed fluxes in each stereoscopic image pair with an accuracy of a few percents (of the average flux) in each pixel. With the stereoscopic tomography we infer also a differential emission measure distribution over the entire temperature range of T {approx} 10{sup 4}-10{sup 7}, with predictions for the transition region and hotter corona in soft X-rays. The tomographic 3D model provides also large statistics of physical parameters. We find that the extreme-ultraviolet loops with apex temperatures of T{sub m} {approx}< 3.0 MK tend to be super-hydrostatic, while hotter loops with T{sub m} {approx} 4-7 MK are near-hydrostatic. The new 3D reconstruction model is fully independent of any magnetic field data and is promising for future tests of theoretical magnetic field models and coronal heating models.

• OSTI ID: 21296272
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 695; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
EXTREME ULTRAVIOLET RADIATION
INTERPOLATION
MAGNETIC FIELDS
ROTATION
SOFT X RADIATION
SUN
TEMPERATURE DISTRIBUTION
THREE-DIMENSIONAL CALCULATIONS
TOMOGRAPHY