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Title: FAST INVERSION OF SOLAR Ca II SPECTRA

We present a fast (<<1 s per profile) inversion code for solar Ca II lines. The code uses an archive of spectra that are synthesized prior to the inversion under the assumption of local thermodynamic equilibrium (LTE). We show that it can be successfully applied to spectrograph data or more sparsely sampled spectra from two-dimensional spectrometers. From a comparison to a non-LTE inversion of the same set of spectra, we derive a first-order non-LTE correction to the temperature stratifications derived in the LTE approach. The correction factor is close to unity up to log τ ∼ –3 and increases to values of 2.5 and 4 at log τ = –6 in the quiet Sun and the umbra, respectively.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. National Solar Observatory (NSO), 3010 Coronal Loop, Sunspot, NM 88349 (United States)
  2. Department of Physics and Astronomy, California State University, Northridge (CSUN), CA 91330-8268 (United States)
  3. Kiepenheuer-Institut für Sonnenphysik (KIS), Schöneckstr. 6, D-79104 Freiburg (Germany)
  4. Leibniz-Institut für Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)
Publication Date:
OSTI Identifier:
22364643
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 798; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALCIUM IONS; CHROMOSPHERE; COMPARATIVE EVALUATIONS; CORRECTIONS; DATA ANALYSIS; EMISSION SPECTRA; LTE; PHOTOSPHERE; STRATIFICATION; SUN; TWO-DIMENSIONAL CALCULATIONS