AAS 203rd Meeting, January 2004
Session 4 Computation, Data Handling and Image Analysis
Poster, Monday, January 5, 2004, 9:20am-6:30pm, Grand Hall

[Previous] | [Session 4] | [Next]

[4.01] QLWFPC2: Parallel-Processing Quick-Look WFPC2 Stellar Photometry based on the Message Passing Interface

K. J. Mighell (National Optical Astronomy Observatory)

I describe a new parallel-processing stellar photometry code called QLWFPC2 which is designed to do quick-look analysis of two entire WFPC2 observations from the Hubble Space Telescope in under 5 seconds using a fast Beowulf cluster with a Gigabit Ethernet local network. This program is written in ANSI/ISO C and uses the MPICH implementation of the Message Passing Interface from the Argonne National Laboratory for the parallel-processing communications, the CFITSIO library (from HEASARC at NASA's GSFC) for reading the standard FITS files from the HST Data Archive and the Parameter Interface Library (from the INTEGRAL Science Data Center) for the IRAF parameter-file user interface. QLWFPC2 running on 4 processors takes about 2.4 seconds to analyze WFPC2 archive datasets u37ga407r.c0.fits (F555W; 300 s) and u37ga401r.c0.fits (F814W; 300 s) of M54 (NGC 6715) which is the bright massive globular cluster near the center of the nearby Sagittarius dwarf spheroidal galaxy. The analysis of these HST observations of M54 lead to the serendipitous discovery of more than 50 new bright variable stars in the central region of M54. Most of the candidate variables stars are found on the PC1 images of the cluster center --- a region where no variables have been reported by previous ground-based studies of variables in M54. This discovery is an example of how QLWFPC2 can be used to quickly explore the time domain of observations in the HST Data Archive. This work is supported by a grant from the National Aeronautics and Space Administration (NASA), Order No. S-13811-G, which was awarded by the Applied Information Systems Research Program (AISRP) of NASA's Office of Space Science (NRA 01-OSS-01).

If you would like more information about this abstract, please follow the link to http://www.noao.edu/staff/mighell/qlwfpc2. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

[Previous] | [Session 4] | [Next]

Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.