Formation of the CII line at 1335 Ångström
Background
One of the strongest lines in the solar UV spectrum comes from singly ionized carbon, at a wavelength of 1335 Å. The line is observed not only in the solar spectrum but also from other stars. C II 1335 will be a central observable with the NASA/SMEX mission Interface Region Imaging Spectrograph (IRIS).Goal
The goal of the project is to show how the C II 1335 line is formed and how it can be used as diagnostics of the solar atmosphere.The line formation should be studied both in static model atmospheres, many-component atmospheres and in dynamic situations.
Method
MULTI is used to solve the equations of statistical equilibrium for a given model atom and model atmosphere.Procedure
As a first step you should study the formation in the semi-empirical atmosphere VAL3C. Use the following files from the directory ~matsc/multi/input:
atom.c22_r8
dscale.c22_r8_val3c
input.c22_r8
input.c22_r8_restart
absdat.c22_r8
These files should be placed in your input directory with the same names as above with the exception of absdat.c22_r8 that should have the name absdat in your local input directory.
Use the run script runc22.csh from ~matsc/multi/run.
You may have to modify some parameters in the files PARAM and PARAMW in the source_dp directory.
Compile and run MULTI.
Study the line at 1335 A and explain how it is formed. Look at the center-to-limb variation of the intensity and look at contribution functions.
As a second step we will look at the lineformation in other atmospheres.