The Impact of NASA's MAST Data Archive

EXPANDING THE FRONTIERS OF SPACE ASTRONOMY The Impact of the MAST Data Archive Dick Shaw, Jenny Novacescu Space Telescope Science Institute The MAST Bibliographies The Barbara A. Mikulski Archive for Space Telescopes (MAST) hosts data from over 20 NASA missions and select ground-based community surveys, plus hundreds of curated data collections that were contributed by the research community. •The primary data products are all science ready, meaning they are calibrated and incorporate complete and accurate metadata •The bulk of the data are available to the public We have assembled mission bibliographies from more than 37,000 refereed science publications published over the past 50 years to study the productivity and impact of the missions hosted at MAST. We have in addition combined the bibliometric data for HST and JWST (our Flagship missions) with the mission program databases to extend our analysis with greater detail. We found that most missions have very high productivity, in large part because of the extraordinary number of archival research articles (i.e., those not produced by the original investigators). The mission papers enjoy large citation rates, which accumulate over at least 15 years. For HST, data from most programs are first published within 1.5 yr. Data Usage Classifications Our software periodically queries over 40 journals in the Astrophysics Data System to identify articles that contain mission identifiers. Four main journals account for most matches. Currently about one-third of the articles in these main journals call out a MAST mission. Staff scientists reviewed matched articles to determine the type of data usage: •A Science result based upon MAST mission data •A mere Mention of a MAST mission (e.g., a citation to prior work) •A paper Influenced by MAST mission data, but not making direct use •A non-genuine match to a mission, to be ignored The lower chart shows the fraction of each classification. This presentation analyzes refereed publications with data usage classified as Science. Most mission corpora are complete through 2022-May, but those for HST and JWST are complete through 2024-Dec. MAST Mission Science Publications Most MAST missions have inspired a high rate of science publications. •Flagship missions (HST, JWST) dominate the publication rate •Smaller missions in aggregate are competitive with the Flagships •The publication rate for retired missions remains strong for decades afterward Guest Investigator vs. Archival Research For HST and JWST, publications authored by the original investigators (GO) are compared to those authored by archival researchers (AR). •By our definition, AR papers must have no authors in common with the original investigators •HST AR papers now exceed GO by >3:1 •JWST AR papers accounted for ~onethird of the total after only 2.5 years HST Observing Programs: Time to First Publication We examined first publications from individual HST observing programs. •The first publication appeared within 2.0 yr for 50% of programs awarded prior to Cy 25 •TTFP decreased to 1.5 yr after the Exclusive Access Period was reduced from 12 mo to 6 mo •About 90% of all programs have at least one publication •The first publication for some programs was based upon archival research Citations to MAST mission science papers The citation rates to mission science papers are very high, and continue to grow. The rapid rise in citations to non-Flagship missions is largely due to the addition of data from new missions to the MAST holdings. Citations by Mission The 2 million citations to MAST mission science articles are heavily weighted to a small fraction of publications, as shown below in the plot of cumulative citation fraction vs. the fraction of mission science papers. •The cumulative distributions seem to follow a 50:10 rule: half of the citations come from the most highly cited 10% of papers, while the least cited half of papers account for only 10% of citations. •The distribution curves are nearly identical for other MAST missions. Evolution in Publishing Some prior bibliographic studies have suggested that both the number of citations per paper and the number of authors per paper has increased substantially over time. Our results are more nuanced. •The median number of authors/paper has grown from one in 1945 to six today. •MAST mission papers often include many authors just after operations begin •Citations rates per paper are similar to journal articles generally •Median citations per paper grew from one in 1945 to about 40 in 2010, then decline •Conclusions about paper or mission impact based upon citation rates must take account of the ~15 years it takes for citations to accumulate