UK ALMA 2025 Hybrid Workshop (20-22 January 2025)

Nancy Rothwell Building 3A.016
The University of Manchester
Manchester, United Kingdom

 

Overview

This workshop will provide an introduction to ALMA and instructions on how to work with data from the observatory and will include sessions on preparing proposals, downloading data from the ALMA archive, calibrating and imaging ALMA data. At the end of the workshop, participants may optionally request tutorials on using advanced ALMA-related tools or request assistance with data calibration, imaging, and analysis for their own projects. While the workshop is aimed primarily at novice ALMA users, particularly from the United Kingdom, other users with higher levels of experience or from other locations are also invited to attend.

The workshop is scheduled from Monday, 20 January, to Wednesday, 22 January in room 3A.016 of the Nancy Rothwell Building (also known as the Manchester Engineering Campus Development), which is located at the north end of the main campus. However, participants may also join remotely if needed. Please contact us if you need any additional information about the workshop.

 

Schedule

(All times are given in GMT.)

 

Monday, 20 January

10:00 Welcome and Introductions
10:30 Introduction to ALMA
11:00 Break
11:30 Introduction to Interferometry
12:00 The Observing Support Tool (the online ALMA simulation tool)
12:30 Lunch
14:00 The Observing Tool (the GUI used for preparing observing proposals)
15:00 The Proposal Review and Observing Process
15:30 Break
16:00 Introduction to CASA
17:00 End

 

Tuesday, 21 January

10:00 The ALMA Science Archive
11:00 Break
11:30 Notes about Downloaded Data
11:45 CARTA (the image viewer designed for interferometric data)
12:30 Lunch
14:00 ALMA WebLog Review
15:00 Imaging Tutorial: Preparation
15:30 Break
16:00 Imaging Tutorial: Continuum Imaging
17:00 End

 

Wednesday, 22 January

10:00 Imaging Tutorial: Spectral Line Imaging
11:00 Break
11:30 Imaging Tutorial: Spectral Line Imaging (continued)
12:30 Lunch
14:00 Advanced Imaging Techniques or One-On-One Support
15:30 Break
16:00 Advanced Imaging Techniques or One-On-One Support (continued)
17:00 End

 

Pre-Workshop Downloads

UK ARC Node staff are available to help with the installation of CASA and any other software needed for the workshop. We will be contacting participants before the workshop to set up Zoom calls to help with the software installation.

 

CASA (ALMA Pipeline Version)

To work on the data calibration, imaging, and analysis activities, the ALMA pipeline version of CASA is required, as this contains many tools and tasks that are not packaged in the non-pipeline version but that are needed for the tutorials in the workshop. We strongly recommend that you install CASA 6.6.1, as we have verified that this works with the example dataset that we will use for the workshop.

CASA is available for both Linux and Mac OS. While it is not supported for Windows, it will work in WSL.

We encourage participants to test that CASA runs correctly in pipeline mode ahead of the workshop. This can be done as follows (please ensure that the appropriate path to CASA is given in each case):

  • Linux (including WSL in Windows):: On the command line, run ~/casa-6.6.1-17-pipeline-2024.1.0.8/bin/casa --pipeline
  • Mac:: On the command line, run ~/CASA_PL_6.6.1.app/Contents/MacOS/casa --pipeline

If successful, a CASA IPython session should open with some print statements including:

INFO: Loaded Pipeline commands from package: h
INFO: Loaded Pipeline commands from package: hif
INFO: Loaded Pipeline commands from package: hifa

If these statements are not visible or an error message is displayed saying that pipeline mode could not be initialised, please ask us for assistance.

A note for Mac OS users

When opening CASA for the first time, the system may indicate that it cannot verify the software and will block it. A workaround is to go into System settings > Privacy & Security > Security, where there will be a warning that CASA was blocked > Click ‘Open Anyway’. This is only required once, and CASA should open as normal in future.

Additionally, the CASA Viewer no longer launches on Mac OS 13 and 14 machines that run on ARM (i.e. M1, M2, etc.) chips (see here for more details). This is not a problem for image visualisation (see CARTA details below), but it does mean that interactive image cleaning is not possible on these systems. The CASA team has been working an a standalone package for interactive cleaning, which resolves this issue. Please see here for more details, but note that this is currently a beta version.

 

CARTA

CARTA is a new image viewer created for use with CASA images, and this viewer will be used frequently during the workshop. The downloads are available from the CARTA Installation page. In general, participants should just use one of the versions of the stand-alone package for this workshop.

  • Linux: Most users should select the x86_64 version of the stand-alone package (which should work on most systems), although an AArch64 version of the package is also available. People working with WSL may want to try version 4.0 (available via this link) if they have problerms with using 4.1.0.
  • Mac: Users should select either the Intel Mac or Apple Silicon Mac stand-alone packages.
  • Windows: CARTA is unavailable for Windows, although the Linux version will work in WSL.

 

ALMA Observing Tool (OT)

One of the workshop sessions is based on using the ALMA Observing Tool, which is used to submit proposals but which is also useful for understanding how ALMA observations are configured. This can be installed on either Windows, Mac, or Linux computers. The installer for the different versions can be download from the Installer Page.

If using the installer is probelmatic, it is also possible to download a tar file from the Tarball Download Page.

 

Example Datasets

The example dataset, which feature a planetary nebula, can be downloaded from the links below. The calibrated visibility data are optional downloads and are only necessary for situations where it is not possible to calibrate the archival data or perform some of the steps in the imaging script.

Archival Data

Optional Pre-Processed Data