Science Highlight





The Additional Representative Images for Legacy (ARI-L) in the ALMA Science Archive (ASA) is an Development project for ALMA upgrade approved by the ALMA Director in December 2018. The project aim was to increase the legacy value of the ALMA Science Archive by bringing the reduction level of ALMA data from Cycles 2-4 close to that of what is processed with the ALMA Imaging Pipeline in more recent Cycles.

The complete set of ARI-L imaging products is very relevant for all science fields and enhances the possibilities of exploitation of archival data.

Indeed, the ARI-L images available in the ASA for Cycle 2-4 datasets:

  • facilitate archive access and data usage for science purposes, also to non-expert data miners,
  • provide a homogeneous view of all data, in order to compare datasets and enable a more conscious download selection,
  • permit to more profitably link the archive to several visualisation and analysis tools (e.g. VO, CARTA, ADMIT, KAFE, ...),
  • allow users to exploit previews similar to those available for following cycles and perform preview image comparisons and combinations.

The project produced and ingested into the ASA a uniform set of full data cubes and continuum images covering at 86% of the data from Cycles 2-4 processable with the ALMA pipeline. These cubes complement the more limited QA2-generated image products which cover only a small fraction (< 10%) of the observed data for those cycles.

The project was leaded by the Italian node of the European ALMA Regional Centre (ARC) in collaboration with staff from the UK and ESO European ARC nodes. 

The ARI-L images  were generated, certified for quality and ingested into the archive as external products. The workflow and rocessing and quality assurance procedures are described in the ARI-L project website and papers (Massardi et al. 2021, and Massardi et al. 2022).

ARI-L image, README and Weblog files can be queried in the ALMA Science Archive through the “ari_l” label in the “Collection” column, visualised in a dedicated preview and downloaded as single file among the "Externally delivered products" in the Request Handler system.

The calibrated Measurement Sets for all the ARI-L delivered MOUS are stored at the Italian Astronomical Archive (INAF-IA2) facilities and are publicly available.They can be requested via e-mail to help-desk@alma.inaf.it .

Examples of the ARI-L products are here.

For more information:


Publication Acknowledgement

The use of the data must be acknowledged using the standard ALMA Publication Acknowledgement statement.

It is suggested and would be appreciated that the publication Massardi et al. (2021) is cited when ARI-L data are used.