ALMA publication statistics

TL;DR

This study provides a comprehensive statistics-driven assessment of ALMA’s scientific impact from 2012–2024, compiling 4,190 refereed papers that cite ALMA data and totaling 169,985 citations across 2,670 projects and 19,265 hours of 12-m-array observing time. It shows a rapidly growing but maturing landscape where archival data increasingly drive publication output, with ~39–40% of 2024 publications using archival data and a global, expanding author community exceeding 9,400 unique contributors. The analysis highlights ISM and star-formation science as dominant in publications, strong productivity in Band 6/7 data, and a high publication fraction (~60–70%), while reporting a persistent time-to-publication lag (median ~2.1 years for first PI publication). ALMA’s impact factor (~8.21 over the past five years) and its pivotal role in VLBI (EHT) corroborate its high scholarly influence, reinforced by the substantial ALMA Science Archive and a growing, international user base that continues to broaden access and collaboration across regions.

Abstract

The success of an astronomical facility is measured by its scientific impact. A principal metric for this impact is the ensemble of peer-reviewed publications based on the observational data obtained by the facility. We present a comprehensive study of the statistics of the 4,190 refereed publications of the Atacama Large Millimeter/Submillimeter Array (ALMA) in the period from 2012 to 2024. The publications have received 169,985 citations and are based on 2,670 ALMA projects totalling 19,265 hours of 12-m-array-equivalent observing time. Our study analyses publication statistics related to various aspects, e.g. science categories, geographical distribution, archival research, time to publication, publication fraction, and citations. We also look into the community and compare ALMA with other facilities. We find that ALMA is a high-impact observatory with an average of 41 citations per publication, ~70% of observed projects published, ~40% of publications making use of archival data in 2024, more than 9,400 unique authors, and a publication evolution following that of HST and VLT. Currently, the impact factor for ALMA publications is larger than that of all other major astronomical facilities. ALMA also plays a pivotal role in very long baseline interferometry (VLBI), substantially contributing to landmark achievements such as capturing the first image of a black hole shadow.

Figures (23)

• Figure 1: Stacked histogram of the evolution of the number of ALMA publications per year. In 2024, for the first time, more than 500 publications were recorded in one year. Whereas the number of publications making only use of PI data (blue) has been roughly constant since 2019, the number of publications using PI data and archival data together (orange) and the number of publications making pure use of archival data (green) are both growing.
• Figure 2: Bands actually used in a given publication as opposed to the data of a given band that were part of the observations in the projects that the publication utilized. The statistics are given for the 12-m-array-equivalent hours of the observations of a given band used in a publication (blue) as well as just counting the bands (orange). On average, if one or more projects have been included in a publication that have observations in Band 10, then in about 35% (but 59% of the hours) of these publications Band 10 was actually used for the science.
• Figure 3: The scientific productivity - here measured in terms of the number of publications and the number of citations - per invested hour of observing time as a function of the receiver band. For each publication and its corresponding citations, only the bands that were actually used in a given publication have been counted (see Figure \ref{['figure:bandsused_vs_bandsobserved']}) and the fractional publication (or citations) have been distributed over the receiver bands and projects weighted by the 12-m-array-equivalent observing hours. Four measurements are shown: in blue the number of publications, taking into account projects from Cycle 1 to Cycle 11, i.e. excluding Cycle 0 as well as observatory projects. In orange the same measurement but counting citations instead of publications. As not all receiver bands were available from Cycle 1 onward, there is a bias in those numbers. To reduce that bias, we also show in green and red the equivalent numbers but now restricting to cycles where all receiver bands were offered. For better comparison, all four measurements were normalised to their largest value, i.e. Band 6 in all cases.
• Figure 4: Evolution of the fraction (blue) and number (orange) of ALMA publications in the high-impact journals Nature and Science.
• Figure 5: The fraction of publications per country is shown as a function of the publication year. For somewhat better visual clarity lines have been used instead of step-functions. Countries that are affiliated with ALMA are show in solid lines, countries that are not affiliated with ALMA are listed in italics and shown with dashed lines. Countries with less than 1% of the publications in 2024 have been regrouped into 'other' (dotted). Chile has a special status as host country and is shown with a dot-dashed line. The countries in the legend are ordered by their publication fraction in 2024.