Chandra Bibliographic Statistics

Tracking Scientific Productivity:

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.

Basic Annual Bibliographic Statistics (as of 2023-03-01) :

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	7791	60	104
2001	198	19525	217	439
2002	330	26606	380	1071
2003	431	29899	520	1828
2004	400	24758	497	2233
2005	447	26309	577	3073
2006	549	36281	688	2317
2007	499	29361	610	2218
2008	517	26262	672	4502
2009	430	24039	550	5443
2010	421	22350	533	4050
2011	440	20759	576	5870
2012	451	21933	547	7532
2013	425	19871	518	7470
2014	404	16065	485	6640
2015	429	16081	489	7285
2016	436	14628	523	7468
2017	471	18218	570	11041
2018	453	10560	504	7548
2019	420	6291	460	9621
2020	388	4014	409	13195
2021	374	2288	403	4387
Total	8968	423889	10788

* Note: this is a lower limit since it refers to Category 1 papers only.

The Chandra Bibliography Database:

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.

(You Know What They Say About) Statistics:

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.

Plots and Data:

Refereed Chandra Science Papers by Publication Year
Citations to Refereed Chandra Science Papers by Publication Year
Plots and Data for Category 1 papers only

Supporting Documents:

NOTES and CAVEATS
DEFINITIONS and CONVENTIONS