GOBASIC: Global Optimization and Broadband Analysis Software for Interstellar Chemistry
GOBASIC is designed for multi-component, simultaneous fit of spectral transitions in a broadband observational line survey. It is based on the JPL/CDMS molecular catalog information, local thermaldynamic equilibrium (LTE) and low opacity assumptions, and MATLAB® Global Optmization Toolbox.
The details of the program design and test results can be find in Radhuber M. L., Zou L., Sanders J. L. and Widicus Weaver S. L., "Global Optimization and Broadband Analysis Software for Interstellar Chemistry (GOBASIC)." Astron. & Astrophys., 2016, 585, A23. (View Paper) The GOBASIC version used in the paper is v4.4.
Our group actively maintains the code. Several internal versions had been updated prior to the publication of the paper.
The most updated version is v5.0.
Updates from v4.5:
- Improve partition function extrapolation. General functional form Q(T) = a1*Ta2*[a3 + exp(a4/T)] is used. Coefficients are fit in advance and loaded into GOBASIC. GOBASIC does not internally fit Q(T) any more.
Updates from v4.4:
- Improve partition function extrapolation. Previous versions used Q(T) = a*T3/2 This function form is only valid when molecule is nonlinear and has no internal rotation or tunneling levels. Current version implements Q(T) = a*Tb where both a and b are fitting parameters.
- Fix a bug in displayresult.m, where the log10 values of column density, instead of column density, was displayed on Matlab Terminal.
- Refactorize a parameter
Update history is also included in the code package
Using GOBASIC, one can fit all these molecules simultaneously. Total fit includes the sum of the flux from other molecules that are not labeled in this sample plot