ALMAGAL

Context. Stars form preferentially in clusters embedded inside massive molecular clouds, many of which contain high-mass stars. Thus, a comprehensive understanding of star formation requires a robust and statistically well-constrained characterization of the formation and early evolution of these high-mass star clusters. To achieve this, we designed the ALMAGAL Large Program that observed 1017 high-mass star-forming regions distributed throughout the Galaxy, sampling different evolutionary stages and environmental conditions. Aims. In this work, we present the acquisition and processing of the ALMAGAL data. The main goal is to set up a robust pipeline that generates science-ready products, that is, continuum and spectral cubes for each ALMAGAL field, with a good and uniform quality across the whole sample. Methods. ALMAGAL observations were performed with the Atacama Large Millimeter/submillimeter Array (ALMA). Each field was observed in three different telescope arrays, being sensitive to spatial scales ranging from ≈1000 au up to ≈0.1 pc. The spectral setup allows sensitive (≈0.1 mJy beam −1 ) imaging of the continuum emission at 219 GHz (or 1.38 mm), and it covers multiple molecular spectral lines observed in four different spectral windows that span about ≈4 GHz in frequency coverage. We have designed a Python-based processing workflow to calibrate and image these observational data. This ALMAGAL pipeline includes an improved continuum determination, suited for line-rich sources; an automatic self-calibration process that reduces phase-noise fluctuations and improves the dynamical range by up to a factor ≈5 in about 15% of the fields; and the combination of data from different telescope arrays to produce science-ready, fully combined images. Results. The final products are a set of uniformly generated continuum images and spectral cubes for each ALMAGAL field, including individual-array and combined-array products. The fully combined products have spatial resolutions in the range 800–2000 au, and mass sensitivities in the range 0.02–0.07 M ⊙ . We also present a first analysis of the spectral line information included in the ALMAGAL setup, and its potential for future scientific studies. As an example, specific spectral lines (e.g., SiO and CH 3 CN) at ≈1000 au scales resolve the presence of multiple outflows in clusters and will help us to search for disk candidates around massive protostars. Moreover, the broad frequency bands provide information on the chemical richness of the different cluster members, which can be used to study the chemical evolution during the formation process of star clusters.

Authors

Institutions

Publication Details

Journal
Astronomy and Astrophysics
Published
2025-03-14
DOI
https://doi.org/10.1051/0004-6361/202452703
Citations
5
Primary Topic
Astronomy and Astrophysical Research
Type
article
Field-Weighted Citation Impact
5.96

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

ALMAGAL

T. Möller, P. Schilke, L. Bronfman, Manuel Merello et al.
5 citations
Astronomy and Astrophysics
Astronomy and Astrophysical Research
5.96
article

ALMAGAL

T. Möller, P. Schilke, L. Bronfman, Manuel Merello, A. Nucara, G. A. Fuller, S. Molinari, M. Benedettini, D.C. Lis, Paul T. P. Ho, C. Battersby, F. Nakamura, J. Wallace, T. Liu, K. L. J. Rygl, A. J. Rigby, P. Sanhueza, F. Fontani, A. S'anchez-Monge, Yongan Tang, Q. Zhang, C. Mininni, S. Walch, G. Stroud, W.-J. Kim, S. Pezzuto, C. L. Brogan, K. Johnston, A. Avison, Sheng‐Yuan Liu, Chi-Yan Law, Ralf S. Klessen, M. R. A. Wells, T. R. Hunter, B. Jones, D. Elia, L. Moscadelli, A. Ahmadi, Yang Su, F. Wyrowski, E. Schisano, L. T. Maud, A. Traficante, R. Kuiper, Alessandro Coletta, Floris S. van der Tak, F. De Angelis, Tianwei Zhang, M.T. Beltr'an, J. D. Soler, Pamela Klaassen, Denise L. Walker, Th. Henning, H. Beuther, J. Allande, E. Dann
article en
5 citations

Abstract

Context. Stars form preferentially in clusters embedded inside massive molecular clouds, many of which contain high-mass stars. Thus, a comprehensive understanding of star formation requires a robust and statistically well-constrained characterization of the formation and early evolution of these high-mass star clusters. To achieve this, we designed the ALMAGAL Large Program that observed 1017 high-mass star-forming regions distributed throughout the Galaxy, sampling different evolutionary stages and environmental conditions. Aims. In this work, we present the acquisition and processing of the ALMAGAL data. The main goal is to set up a robust pipeline that generates science-ready products, that is, continuum and spectral cubes for each ALMAGAL field, with a good and uniform quality across the whole sample. Methods. ALMAGAL observations were performed with the Atacama Large Millimeter/submillimeter Array (ALMA). Each field was observed in three different telescope arrays, being sensitive to spatial scales ranging from ≈1000 au up to ≈0.1 pc. The spectral setup allows sensitive (≈0.1 mJy beam −1 ) imaging of the continuum emission at 219 GHz (or 1.38 mm), and it covers multiple molecular spectral lines observed in four different spectral windows that span about ≈4 GHz in frequency coverage. We have designed a Python-based processing workflow to calibrate and image these observational data. This ALMAGAL pipeline includes an improved continuum determination, suited for line-rich sources; an automatic self-calibration process that reduces phase-noise fluctuations and improves the dynamical range by up to a factor ≈5 in about 15% of the fields; and the combination of data from different telescope arrays to produce science-ready, fully combined images. Results. The final products are a set of uniformly generated continuum images and spectral cubes for each ALMAGAL field, including individual-array and combined-array products. The fully combined products have spatial resolutions in the range 800–2000 au, and mass sensitivities in the range 0.02–0.07 M ⊙ . We also present a first analysis of the spectral line information included in the ALMAGAL setup, and its potential for future scientific studies. As an example, specific spectral lines (e.g., SiO and CH 3 CN) at ≈1000 au scales resolve the presence of multiple outflows in clusters and will help us to search for disk candidates around massive protostars. Moreover, the broad frequency bands provide information on the chemical richness of the different cluster members, which can be used to study the chemical evolution during the formation process of star clusters.

Astronomy and AstrophysicsVol. 696
University of Rome Tor Vergata (IT), Leiden University (NL), University of Leeds (GB), Institute of Astronomy and Astrophysics, Academia Sinica (TW), European Southern Observatory (DE), Jet Propulsion Laboratory (US), Harvard University (US), University of Connecticut (US), Pontificia Universidad Católica de Chile (CL), University of Groningen (NL), University of Cologne (DE), National Institutes of Natural Sciences (JP), The Graduate University for Advanced Studies, SOKENDAI (JP), Heidelberg University (DE), National Radio Astronomy Observatory (US), Shanghai Astronomical Observatory (CN), Arcetri Astrophysical Observatory (IT), University of Manchester (GB), Laboratoire Univers et Théories (FR), Max Planck Institute for Extraterrestrial Physics (DE), Institut d'Estudis Espacials de Catalunya (ES), Institute for Space Astrophysics and Planetology (IT), Royal Observatory (GB), SKA Observatory (GB), Max Planck Institute for Astronomy (DE), Institute of Space Sciences (ES), Istituto di Radioastronomia di Bologna (IT), East Asian Observatory (US), Zhejiang Lab (CN), Forschungsstätte der Evangelischen Studiengemeinschaft (DE), Center for Astrophysics Harvard & Smithsonian (US), Institut de Ciència de Materials de Barcelona (ES), Max Planck Institute for Radio Astronomy (DE), National Astronomical Observatory of Japan (JP), Laboratoire d'Étude de l'Univers et des Phénomènes Extrêmes (FR), University of Florence (IT), Space Research Organisation Netherlands (NL), UK Astronomy Technology Centre (GB), University of Lincoln (GB), University of Duisburg-Essen (DE), University of Chile (CL), The University of Tokyo (JP), Sapienza University of Rome (IT)
Smithsonian Institution, National Aeronautics and Space Administration, California Institute of Technology, European Commission, Deutsche Forschungsgemeinschaft, National Natural Science Foundation of China, Chinese Academy of Sciences, Universität zu Köln, Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, Science and Technology Facilities Council, Agencia Estatal de Investigación
Openalex Percentile: Top 4%
Astronomy and Astrophysical Research
5.96
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.