Common Astronomy Software Applications¶
CASA, the Common Astronomy Software Applications, is the primary data processing software for the Atacama Large Millimeter/submillimeter Array (ALMA) and Karl G. Jansky Very Large Array (VLA), and is often used also for other radio telescopes.
CASA 6.2.1 can now be downloaded for general use. CASA 6.2.1 includes a pipeline that has been validated for ALMA and VLA operations. CASA 6.2.1 and its included pipeline is functionally equivalent to CASA 6.2.0, and has the following added fixes and features:
Fixed known issue with channel averaging of a caltable in PlotMS. Resolved slow performance and crashes.
A significant slow down in the flagdata task present in 6.2 (up to 3-4x, especially in ‘summary’ mode) has now been fixed, bringing the CASA 6.2.1 flagdata task to a performance comparable with CASA 6.1.
Fix spw classification algorithm to correctly identify 256 channel (ACA correlator) spws with bandwidths of < 2 GHz as FDM windows and not (incorrectly) TDM.
Fix defects that prevented using the Splatalogue offline database with spectral profile tool in the CASA viewer.
Running tclean using a list of MeasurementSets which exhibit very large Doppler frequency changes between them (i.e., large TOPO offsets in channels) was found to result in crashes due to memory limits being crossed. A fix was implemented to switch to a different mode when such situations might occur (specifically, if the weight density grid is larger than 10% of the cube grid in memory usage). This different mode uses less memory but results in a longer runtime as tclean must make multiple passes through all MSs.
Minor bug fixes to plotbandpass and log messages upon startup to report measures table version.
For more details on these and other new features, see the CASA 6.2 Release Notes.
CASA is developed by an international consortium of scientists based at the National Radio Astronomical Observatory (NRAO), the European Southern Observatory (ESO), the National Astronomical Observatory of Japan (NAOJ), the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), CSIRO Astronomy and Space Science (CSIRO/CASS), and the Netherlands Institute for Radio Astronomy (ASTRON), under the guidance of NRAO.