mountain profile Institute for Astronomy University of Hawaii

Clumpfind

 

Clumpfind is a rather goofy name to describe a procedure that I developed during the course of my thesis work at the University of California at Berkeley in collaboration with Eugene de Geus and Leo Blitz. See our ApJ paper for a description of it's application and testing.

Primarily designed for analyzing radio observations of molecular clouds, it works on 3d (position-position-velocity) data cubes, searches for local peaks of emission, and follows them down to lower intensity levels. The end result is a decomposition of the data cube into a set of structural units ("clumps") in which the emission is concentrated.

Clumpfind has been coded into IDL and is available as a tar package. You can also look at some instructions on how to use it and an example of how it works. The code was made more efficient using the SEARCH3D function in IDL by Mordecai-Mark Mac Low and I have since (June 2004) done a complete rewrite to make it simpler, quicker, and easier to follow.

A 2-d version is also available by popular request. Also completely rewritten as of June 2004.

Clumpfind has also been made a part of the MIRIAD data reduction package for the BIMA interferometer. A memo describing its use is available. The MIRIAD version is written in FORTRAN and dates back to the dark ages when I was a graduate student. It is probably very slow and I haven't used it in over a decade. I recommend working with the IDL version. Nevertheless, the memo may prove helpful in visualizing how the algorithm works.

If you have any problems with setting up or running these programs please contact me by email or phone. If your analysis results in a publication, please cite the original paper. Happy clump-finding!