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Non-LTE radiating acoustic shocks and Ca II K2V bright pointsWe present, for the first time, a self-consistent solution of the time-dependent 1D equations of non-LTE radiation hydrodynamics in solar chromospheric conditions. The vertical propagation of sinusoidal acoustic waves with periods of 30, 180, and 300 s is calculated. We find that departures from LTE and ionization recombination determine the temperature profiles of the shocks that develop. In LTE almost all the thermal energy goes into ionization, so the temperature rise is very small. In non-LTE, the finite transition rates delay the ionization to behind the shock front. The compression thus goes into thermal energy at the shock front leading to a high temperature amplitude. Further behind the shock front, the delayed ionization removes energy from the thermal pool, which reduces the temperature, producing a temperature spike. The 180 s waves reproduce the observed temporal changes in the calcium K line profiles quite well. The observed wing brightening pattern, the violet/red peak asymmetry and the observed line center behavior are all well reproduced. The short-period waves and the 5 minute period waves fail especially in reproducing the observed behavior of the wings.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Carlsson, Mats (Inst. of Theoretical Astrophysics Oslo, Norway)
Stein, Robert F. (Michigan State Univ. East Lansing, United States)
Date Acquired
August 15, 2013
Publication Date
September 20, 1992
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 397
Issue: 1
ISSN: 0004-637X
Subject Category
Funding Number(s)
Distribution Limits