Latest version: CASA 6.6

The Release Notes and Known Issues of the 6.6 release are available in

CASA 6.6 is based on Python 3, and available either as a downloadable tar-file distribution with Python environment included, or as a modular version that can be installed with pip-wheels.

Manual processing can be done with any CASA version, but ALMA and VLA pipelines may differ and are not always included, so download the correct CASA version for pipeline use.

(RedHat 7, 8)
(OS 11, 12)
General Use
CASA 6.6.4 (RH7/Py3.8)
CASA 6.6.4 (RH8/Py3.8)
. CASA 6.6.4 (RH8/Py3.10) [a]
CASA 6.6.4 (OS12+/Py3.8/Intel) [b]
CASA 6.6.4 (OS13/Py3.10/ARM) [a,b]
CASA 6.6.4 (OS14/Py3.10/ARM) [a,b]
ALMA Pipeline

(Notes) ALMA: Version CASA, includes a pipeline validated for ALMA (pipeline version 2023.1.0.125).

For more information, see the ALMA Science Pipeline website.
CASA 6.5.4 (RH7/8) CASA 6.5.4 (OS11)*
VLA Pipeline

(Notes) VLA: Version CASA, includes a pipeline validated for VLA (pipeline version 2023.1.0.125).

For more information, see the VLA Science Pipeline website.
CASA 6.5.4 (RH7/8) CASA 6.5.4 (OS11)*
[a] The Python 3.10 versions on Linux and Mac do not include task wvrgcal.

[b] The ARM OS 13 and 14 versions do not include the CASA Viewer. Users of ARM Mac OS 13 may also access the Viewer by using the Intel build for OS12+, but the Viewer has a known incompatibility when the Intel Mac OS 12+ build is run on Mac OS 14. Please use CARTA for image viewing on these platforms. See the Know Issues in CASA Docs for details.

Pipelines: a patch version with a new pipeline (version 2023.1.0.125) was made available on 22 Feb 2024. The only difference with version 2023.1.0.124 is a change to allow ALMA data processed with PL2021 and PL2022 to successfully be restored using PL2023.
The above CASA versions can also be downloaded from our NAOJ CASA mirror site and NAOJ CASA-pipeline mirror site, or via Google Drive.

CASA is only fully validated against the operational configuration of NRAO instruments (currently RHEL8/Python 3.8).

The CASA versions listed above are built on specific versions of Linux RedHat and Mac OS, but they are expected to work for multiple LINUX and Mac computer operating systems, certain Ubuntu versions. See the OS compatibility matrix in CASA Docs, or see 'Version Support' below for more details.

*Note for pipelines: Pipelines are only tested and validated on Linux RedHat, and are not supported for Mac OS. For more information, see the ALMA Science Pipeline website and the VLA Science Pipeline website.

*Note for VLBA: VLBI functionality has been implemented in CASA for the processing of VLBI continuum and spectral line observations, based on development by the CASA-VLBI group at JIVE (see this article). For the NRAO Very Long Baseline Array (VLBA), CASA may be used for calibrating and imaging relatively simple VLBA data sets. Do not use CASA if your VLBA project involves polarimetry, astrometry, low frequencies (< 4 GHz), or data from before December 2009. Also, do not use CASA if your project requires fringe-rate mapping or the use of antab files. See the CASA VLBA Calibration and Imaging page for more details.

CASA 6: pip-wheel installation

CASA 6 can optionally be installed through modular pip-wheels, with the flexibility to build CASA tools and tasks into a customized Python environment. Instructions on how to install the pip-wheel version of CASA 6 can be found in CASA Docs: CASA 6 Installation

The modular pip-wheel version is not yet used in production by ALMA and VLA, and does not include any pipelines.

Pre-release versions of CASA can be found here (see also this download through Google Drive). Pre-release versions reflect ongoing CASA development and are not supported. Use at your own discretion.

CASA 6.6 is fully validated against the operational configuration of NRAO instruments, which currently is Linux RHEL8/Python 3.8.

Automated verification tests have been performed for a number of Operating Systems and Python versions. The following table in CASA Docs gives an overview of the automated testing done for CASA.

Manual package testing has been performed for the OS version that are included in the download table at the top of this page.

Other systems on which we expect CASA to work, including certain versions of Ubuntu, are listed in the compatibility matrix on CASA Docs. CASA accepts bug reports for all combinations of OS and Python that are listed there. CASA may also work on other flavors of Linux, but this is at the discretion of users. Some tips from the community can be found here.

NRAO has installed a suite of CASA and pipeline versions for local users, visitors, and users who request remote access to NRAO machines. More information on running CASA locally at NRAO can be found here.

To efficiently run CASA, a balanced hardware configuration regarding memory, processing power and file I/O may be required. Recommendations on the CASA hardware requirements for VLA and ALMA data can be found on this 'Hardware Requirements' page.

DISCLAIMER: CASA now collects usage statistics including task execution timings and crash reports. This data will be periodically sent back to NRAO to guide future priorities and decision making. All collection is anonymous and contains no scientific or personal data. For more information, or instructions on how to disable telemetry recording, see CASA Docs