Solar Radiation Physical Modeling (SRPM)
This dataset represents the entire solar spectra between 200 nm and 100 microns as computed by the Solar Radiation Physical Modeling version 2 system (SRPMv2), using the model 1001 for feature B shown in the paper:
- Fontenla, J.M., Curdt, W., Haberreiter, M., Harder, J., and Tian H., Semiempirical models of the solar atmosphere. III. Set of Non-LTE Models for Far-Ultraviolet/Extreme-Ultraviolet Irradiance Computation, ApJ, 707, 482-502, doi: 10.1088/0004-637X/707/1/482, 2009.
This dataset and other related information is also available at http://www.digidyna.com.
The computed spectrum has been created by:
Laboratory for Atmospheric and Space Physics (LASP)
E-mail: Juan Fontenla
The dataset consists of several FITS files containing the various spectral ranges and either the irradiance (i.e. full disk flux at 1 AU) or the disk center intensity spectra depending on the file. The units are indicated in the FITS header and the data are stored as a 2D array consisting of two rows, one of which holds wavelengths and the other contains either the irradiance or the intensity.
Please be aware that the points are not evenly spaced but they are snapshots (not bins) at a resolution that tracks the spectral lines and is coarser where lines are absent. If you need evenly spaced data please contact us and we can perform a convolution with a fictitious or real instrument profile.
These data correspond to an extreme quiet-Sun case, i.e. the inter-network solar surface feature labeled B and the current physical model for that feature labeled 1001. These calculations contain a number of species, presently 50, in which NLTE was computed. NLTE is quite important for deep lines even in the visible and IR ranges.
The near-UV (NUV) files contain the preliminary spectrum for the 200-300 nm range. These spectra fit the observed irradiance and intensity fairly well overall, but there are the following known issues:
- The continuum opacity in that range is still being evaluated by quantum-mechanical calculations and what was used here is only preliminary.
- There are known missing lines in the calculations and work is being done to include a number of them. Unfortunately reliable atomic data is scarce on these.
- The lines from the Fe I quintet are currently too saturated. We are assessing whether this is caused by incorrect collisional rates or otherwise. At some wavelengths these produce lines that are deeper than the observed.
- The edge at 200 nm (often called Al I edge but is indeed due to several species and only partially due to Al I) seems insufficiently deep. Perhaps this is due to incorrect cross-section in some of the several overlapping continua. A paper describing these calculations and test results is in preparation.