rvfit is a code for fitting non-precessing keplerian radial velocity (RV) curves for double-line and single-line binary stars or exoplanets. It fits a simple keplerian model to the observed RV and compute the seven parameters (six for a single-line system) from the model. Some of the parameters can be fixed beforehand if they are known, for instance, if photometric observations are avaliable.

The fit is done using an Adaptive Simulated Annealing algorithm optimized for this specific task. Simulated Annealing methods are powerful heuristic algorithms to minimize functions in multiparametric spaces.

rvfit is provided with aditional procedures, instructions and a working example.

This code was developed in IDL 7.0.


To compute the uncertainties in the fitted parameters in a quick way rvfit implements the computation of the Fisher matrix in the minimum of the Chi squared found. If a more elaborate way is needed we implemented an Markov Chain Monte Carlo (MCMC) method which scans the chi squared distribution in the neighbourhood of the solution found.


This code needs some external procedures in IDL. In particular, you need to have installed the procedures from the The IDL Astronomy User's Library from Goddard Space Flight Center. Also you need the pxperfect.pro procedure from Craig T. Markwardt to do pretty Postscript plots and figures.


If you use this code for your publication, please, include this reference:

Iglesias-Marzoa, R., López-Morales, M., Arévalo-Morales, M.J., 'The rvfit Code: A Detailed Adaptive Simulated Annealing Code for Fitting Binaries and Exoplanets Radial Velocities', PASP, 2015, 127, 567.

You have here a link to the paper in NASA ADS and here a link to ASCL.