The Solar ALMA Science Archive (SALSA)

TL;DR

The Solar ALMA Science Archive (SALSA) provides standardized, science-ready solar observation data from ALMA, enabling easier access, analysis, and reproducibility for solar physicists.

Contribution

This work introduces SALSA, a comprehensive archive of solar ALMA data with standardized headers and auxiliary tools, facilitating routine data reduction and analysis.

Findings

SALSA contains time series of interferometric images at 1-2 second cadence.

Standardized headers improve data reproducibility and integration.

Links to co-observations enhance multi-instrument solar studies.

Abstract

In December 2016, the Atacama Large Millimeter/submillimeter Array (ALMA) carried out the first regular observations of the Sun. These early observations and the reduction of the respective data posed a challenge due to the novelty and complexity of observing the Sun with ALMA. The difficulties with producing science-ready time-resolved imaging products in a format familiar and usable by solar physicists based on the measurement sets delivered by ALMA had so far limited the availability of such data. With the development of the Solar ALMA Pipeline (SoAP), it has now become possible to routinely reduce such data sets. As a result, a growing number of science-ready solar ALMA datasets is now offered in the form of Solar ALMA Science Archive (SALSA). So far, SALSA contains primarily time series of single-pointing interferometric images at cadences of one or two seconds. The data arrays are provided in FITS format. We also present the first version of a standardised header format that accommodates future expansions and fits within the scope of other standards including the ALMA Science Archive itself and SOLARNET. The headers also include information designed to aid the reproduction of the imaging products from the raw data. Links to co-observations, if available, with a focus on those of the Interface Region Imaging Spectrograph (IRIS), are also provided. SALSA is accompanied by the Solar ALMA Library of Auxiliary Tools (SALAT) that contains IDL and Python routines for convenient loading and quick-look analysis of SALSA data.