Common Astronomy Software Applications Update


Figure 1

Figure 1: Screen capture of the new Qt based plotter showing EVLA WIDAR correlator data over a 200 MHz bandpass centered at 1.23 GHz. While still under development, this new plotter is at least an order of magnitude faster than the older matplotlib plotter (plotxy). Expanded capability will be available for release 3.0.0.


Figure 2

Figure 2: Australia Telescope Compact Array + Parkes image of Centaurus A comprised of 406 individual pointings. The image was created in CASA with multiscale clean. Image courtesy Ilana Feain, Tim Cornwell, & Ron Ekers (CSIRO/ATNF), R. Morganti (ASTRON), N. Junkes (MPIfR). See


The Common Astronomy Software Applications (CASA) package being developed by NRAO and ALMA will be used for offline reduction and analysis of both ALMA and EVLA data. CASA is fully scriptable and offers a growing suite of data reduction tasks written in C++ with a Python interface, plotting through matplotlib, and a Qt-based Viewer and new experimental plotter (plotms, see Figure 1).

CASA is now being used regularly for ALMA commissioning in Chile, and to fill and inspect data from the new EVLA correlator. Over the last year, CASA tutorials have been held in Santiago, Chile; Socorro, NM; Garching, Germany; Mitaka, Japan; Hamilton, Canada; and Paris, France; reaching ~ 200 participants. Additional tutorials are planned for 2010 and beyond. CASA supports direct import of data in ALMA, VLA, and EVLA formats, and almost any data that can be written to uv-fits can also be imported and reduced (e.g., BIMA, CARMA, SMA, ATCA [see Figure 2]).

The CASA package is currently on Beta release version 2.4.0, and is available to the astronomical community for download from the website, after registration. A CASA helpdesk is also available from the same site. Please try CASA on your own data and join us in our efforts to improve and expand its capabilities. More information on the status of CASA, and its current capabilities can be found at Example scripts and data to get you started can also be found at this website.

The next release of CASA (release 3.0.0), expected shortly before January 2010, will be used to process early science data from the new EVLA WIDAR correlator, and will be the first non-beta release.