Author: Emmanuel Di Folco

2025-05: New demo scripts

New interactive demo scripts are available.

This includes the following possibilities:

  • simulate (setting up an ALMA simulation)
  • polar (handling polarization data)
  • advanced (spectral line cases: imaging with continuum and multi-scale spectral clean)
  • selfmosaic (selfcal demonstration on a spectral line case for a Mosaic)
  • restart (continuum + spectral line case using CLEAN /RESTART option)

Just type @gag_demo:demo to start with, and enter your preferred demo name at MYDEMO = to get it running.

2025-05-15: New Major Release (4.5)

The new version (4.5-01, April 2025) is now fully available for installation on Linux, Windows and MacOs (including a MacPorts package).

Version 4.5 is a critical release. The major improvements include:

  • Self-calibration of Mosaics for multiple channels
  • More robust PIPELINE operation
  • Better noise estimate on data cubes (STATISTIC)
  • Methods GUETH and SAULT available for Mosaics
  • New engine for MODEL command using Clean Components
  • New engine for Self-calibration on very wide bands
  • Command UV_CONTINUUM is deprecated: UV_MAP /CONT and UV_FIT /CONT should be used instead

2024-12-12: New Major Release (4.4)

The new version (4.4-01, December 2024) is now fully available for installation on Linux, Windows and MacOs (including a MacPorts package).

Version 4.4 is a major release with numerous improvements compared to Version 4.2. The most significant changes are :

  • Full polarization support.
  • More tools to handle non regular and/or non contiguous frequency axes: see commands UV_MERGE, UV_LINEARIZE
  • Better handling for Proper Motion (a reference epoch can now be specified)
  • Better Multiple spatial scales clean with command GCLEAN
  • Improved SELFCAL for wide band data.
  • New REPORT command to prepare a PDF summary of an observation set, before and after the PIPELINE execution.

2024-04🪲: PIPELINE /MODE SURVEY

Bug corrected in the distributed version 4.0 (and beyond):

PIPELINE /MODE SURVEY was not working properly when strong lines were present in spectral window, because line subtracting was improperly done, and contaminated the full bandwidth.

Note that the PIPELINE /MODE ALL with NO Catalog was similarly affected, whereas other modes (including PIPELINE /MODE ALL with a Catalog) were not affected by this issue.

2024-04🪲: PIPELINE/Line identification

Bug corrected in the distributed version 4.0 (and beyond):

Description: PIPELINE crashes (in Survey mode): Continuum image could not be created.

This was due to incorrect channel flagging when a strong/broad line is present close to the edge of a frequency band. In some cases, too many (if not all) channels were flagged, resulting in no continuum channels.

Recommandation: you may test first the line identification with the UV_PREVIEW command before starting the imaging process with the PIPELINE (adjusting TAPER, SMOOTH and CLIP variables may help, if the problem persists in exotic cases).