کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6906079 862892 2016 19 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Time-dependent tomographic reconstruction of the solar corona
ترجمه فارسی عنوان
بازسازی توموگرافی وابسته به زمان وابسته به خورشید
کلمات کلیدی
خورشید: کرونا، خورشید: ساختارهای کرونالی، توموگرافی،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی کامپیوتر نرم افزارهای علوم کامپیوتر
چکیده انگلیسی
Solar rotational tomography (SRT) applied to white-light coronal images observed at multiple aspect angles has been the preferred approach for determining the three-dimensional (3D) electron density structure of the solar corona. However, it is seriously hampered by the restrictive assumption that the corona is time-invariant which introduces significant errors in the reconstruction. We first explore several methods to mitigate the temporal variation of the corona by decoupling the “fast-varying” inner corona from the “slow-moving” outer corona using multiple masking (either by juxtaposition or recursive combination) and radial weighting. Weighting with a radial exponential profile provides some improvement over a classical reconstruction but only beyond ≈3R⊙. We next consider a full time-dependent tomographic reconstruction involving spatio-temporal regularization and further introduce a co-rotating regularization aimed at preventing concentration of reconstructed density in the plane of the sky. Crucial to testing our procedure and properly tuning the regularization parameters is the introduction of a time-dependent MHD model of the corona based on observed magnetograms to build a time-series of synthetic images of the corona. Our procedure, which successfully reproduces the time-varying model corona, is finally applied to a set of 53 LASCO-C2 pB images roughly evenly spaced in time from 15 to 29 March 2009. Our procedure paves the way to a time-dependent tomographic reconstruction of the coronal electron density to the whole set of LASCO-C2 images presently spanning 20 years.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Astronomy and Computing - Volume 17, October 2016, Pages 144-162
نویسندگان
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