Institute of Astronomy  

 Bob Carswell's page


Bob Carswell
Institute of Astronomy

Madingley Road
Cambridge   CB3 0HA
Office: Hoyle 16

Phone:            +44.1223.337514
Switchboard: +44.1223.337548
Email:  rfc (at

The main use for this page is to provide links various versions of a Voigt profile fitting program. The code is now fairly stable, though there are probably bugs in the more obscure corners of it. The downloadable gzipped tarfile also includes another program, rdgen, which may be used to set up files for vpfit, and generally looking at spectroscopic data.

VPFIT 11.2 VPFIT11.1 (here as a gzipped tarfile) has passed the standard tests so should generally be OK. The documentation is included in the tarfile.

For those using Overleaf the most up-to-date version of the VPFIT documentation may be found at

A later fairly stable version VPFIT12.0 (also a gzipped tarfile) should also generally be OK. This is now the version which will be modified if somebody reports a possible bug, or ambiguity in the documentation.

If you want older versions (vpfit11.1, 11.0, 10.4, 9.5) then these are still available. Please ask, or, for now, look at vpfit.html.

A somewhat dated collection of data showing the redshift evolution of the Lyman alpha forest, covering redshifts up to z=6.3.

Other links

Last update: 24 October 2019
by rfc