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Evolution of temperature in granule and intergranular space
Author(s) -
Koza J.,
Bellot Rubio L.R.,
Kučera A.,
Hanslmeier A.,
Rybák J.,
Wöhl H.
Publication year - 2003
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200310122
Subject(s) - granule (geology) , intergranular corrosion , photosphere , astrophysics , physics , materials science , thermodynamics , microstructure , spectral line , composite material , astronomy
The temporal evolution of temperature in a dissolving granule and in an adjacent intergranular space is presented. The semi‐empirical evolutionary models have been calculated using an inversion method applied to 4‐min time series of Stokes I spectral line profiles. The models are presented in the form of the functional dependence of temperature T (log τ 5 , t ) on optical depth τ 5 at 500 nm and time t . The observed disappearance of the granule is accompanied with overall cooling of the granular photosphere. Temperature changes greater than 100 K have been found in deeper (log τ 5 ≥ 0) and upper layers (log τ 5 ≤ –2) whereas the intermediate layers are thermally stable. The intergranular space, which is 2 arcsec off the granule, keeps the temperature structure of the layers from log τ 5 = 0.5 to log τ 5 = –2 without global evolutionary changes except short‐term and spatially confined heating. Finally, the significant temperature changes in the upper layers (log τ 5 ≤ 2.5) observed during the time interval of 4 min are found to be typical for the granular and intergranular photosphere.