To evaluate the relative scientific effectiveness of Chandra observations, we have undertaken to compile and study data on related publications. Across institutions and even across disciplines, professional publications and citations represent the most commonly used and accepted method of tracking scientific productivity. See the March 2004 Newsletter article describing this effort.
The basic annual bibliographic statistical data for the Chandra X-ray
Observatory pertain to papers on Chandra observations. These papers fall into
two groups: those that present specific Chandra observations
(Category 1) and those that refer to
published Chandra results with complementary observations, follow-up
analysis, or theoretical analysis (Category 2
with flags A, B, or C). We define these as Chandra Science Papers.
Year |
Refereed Chandra Science Papers |
Number of Citations to these Papers |
All Chandra Science Papers |
Observations Published in Refereed Papers * |
---|---|---|---|---|
2000 | 55 | 8105 | 60 | 104 |
2001 | 198 | 20168 | 217 | 439 |
2002 | 330 | 27793 | 380 | 1074 |
2003 | 431 | 31516 | 521 | 1830 |
2004 | 400 | 26087 | 497 | 2233 |
2005 | 447 | 28050 | 578 | 3089 |
2006 | 549 | 39856 | 688 | 2317 |
2007 | 499 | 32166 | 610 | 2325 |
2008 | 517 | 28658 | 672 | 4502 |
2009 | 432 | 26377 | 552 | 5444 |
2010 | 421 | 25071 | 534 | 4050 |
2011 | 441 | 23321 | 577 | 5871 |
2012 | 453 | 25206 | 552 | 7534 |
2013 | 425 | 22778 | 518 | 7470 |
2014 | 404 | 19923 | 491 | 6705 |
2015 | 429 | 20253 | 491 | 7411 |
2016 | 440 | 18710 | 530 | 7473 |
2017 | 472 | 24753 | 579 | 11065 |
2018 | 459 | 14963 | 515 | 7935 |
2019 | 421 | 10570 | 471 | 9748 |
2020 | 390 | 7912 | 415 | 13202 |
2021 | 378 | 6428 | 410 | 4647 |
2022 | 367 | 4885 | 378 | 6299 |
2023 | 440 | 3605 | 453 | 6303 |
2024 | 452 | 2001 | 465 | 17140 |
Total | 10250 | 499155 | 12154 |
* Note: this is a lower limit since it refers to Category 1 papers only.
The Chandra Bibliography Database allows the public to search all Chandra-related articles and to follow links from the data to the literature, as well as from the literature to the data. Thanks to the Astrophysics Data System (ADS), publication data are highly complete, and relatively easy to track. We query the ADS daily for publications related to Chandra or to X-ray astronomy, and we are complete from before Chandra's launch. We review the publications, categorize them by several different parameters, and enter them into the Bibliography Database. For publications that present, analyze, or refer to Chandra data, we determine the ObsIds involved (either from the text or by asking the authors). ObsIds allow links to other information, such as Chandra Proposal Database items like scientific category and proposal type.
The Chandra Biliography Database allows for the compilation of a
large number of publication statistics. We create selected data
tables and plots, linked below, which are updated monthly. The
resulting plots and statistics have the potential for
misinterpretation, unless one is alert to embedded assumptions and
details affecting the tally. For instance, most plots linked here (except
those by publication year) include only refereed journal articles that present
specific Chandra observations, and all plots tally only programs whose
observations are complete. We
strongly recommend reading both the NOTES
and CAVEATS and the
DEFINITIONS and
CONVENTIONS,
as a guide for interpreting the plots linked below.
If you have pressing questions or concerns, please
contact Paul Green
of the Chandra Director's Office.
Refereed Chandra Science Papers by Publication Year
Citations to Refereed Chandra Science Papers by Publication Year
Plots and Data for Category 1 papers only