Astrophysics

Chandra

9,201 tracked publications and 455,447 citations from 1999–2026. Chandra X-ray Observatory. Launched 1999. Life-cycle cost: $7.5B in 2025 dollars. Active Mission Window September 1, 1999 to January 1, 2024: 8,286 publications, 510 top-10% credit.

Pointed Observatory · h-index 240 · 1,089 papers with 100+ citations · prime mission ended 2004

Lifetime

Scope Papers published from the first full month after science operations begin through 2 years after the mission ends. Citations are counted through the third calendar year after each paper appears. Methods Papers published from the first full month after science operations begin through 2 years after the prime mission ends. Citations are counted through the third calendar year after each paper appears. Methods Every tracked publication to date, with every citation to date. Methods

Key measures

Active Mission Window · papers September 1, 1999 to January 1, 2024
Tracked publicationsTracked publications: peer-reviewed research papers we found for the mission. The list may not be complete. Methods8,286
CitationsCitations received by the tracked publications in the selected scope. The two windowed scopes count each paper’s citations only within its citation window. Methods158,793
Mean citations per publicationMean citations: total citations divided by tracked publications in the selected scope. One blockbuster paper can lift it. Methods19
Median citations per publicationMedian citations: the middle paper’s citation count in the selected scope; half the papers have more, half fewer. A single blockbuster sways it less than the mean. Methods12
Uncited publicationsUncited publications: papers with no citations in the selected scope. Methods323 (3.9%)
Top-10% creditTop 10%: among the 10% most-cited papers from this division’s missions, ranked against papers published around the same time. A paper naming several missions is split evenly among the missions in this division that claim it, so counts can be fractional. Methods510 · 10% of division
Top-1% creditTop 1%: among the 1% most-cited papers from this division’s missions within the selected window. Not adjusted for publication year. A paper naming several missions is split evenly among the missions in this division that claim it, so counts can be fractional. Methods37 · 7.5% of division
Lifetime indices · every tracked publication to date, in any scope
h-indexh-index: the largest h such that h papers have at least h citations each. It only grows with time, so older missions score higher. Methods240
g-indexg-index: the largest g for which the g most-cited papers together hold at least g² citations. Like the h-index, but it lets the most-cited papers count for more. Methods366
m-index, as of October 4, 2026m-index: a mission’s h-index divided by the years since its first peer-reviewed paper. It falls every 1 January even when nothing else changes, so it belongs to the date shown; it also discounts the long operating life that larger missions paid for. Methods8.6
toritori (total research impact, from ADS): for every paper citing one of the mission’s papers, 1 divided by the citing paper’s reference count times the cited paper’s author count, summed, with self-citations removed. It favors citations from papers with short reference lists and from outside the mission’s own authors. Computed over the tracked citation graph, which can be slightly incomplete. Methods1,485
riqriq (research impact quotient): 1,000 times the square root of tori, divided by the years since the mission’s first paper. A rate, not a total, so it does not keep growing with age the way the h-index and tori do. Methods1,328

Tracked publications

  1. On the Absorption of X-Rays in the Interstellar Medium

    Wilms, J., 2000, ApJ

    3,826 citations

  2. First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

    Event Horizon Telescope Collaboration, 2022, ApJ

    2,232 citations

  3. A Direct Empirical Proof of the Existence of Dark Matter

    Clowe, Douglas, 2006, ApJ

    2,130 citations

  4. Collisional Plasma Models with APEC/APED: Emission-Line Diagnostics of Hydrogen-like and Helium-like Ions

    Smith, Randall K., 2001, ApJ

    1,986 citations

  5. The Great Observatories Origins Deep Survey: Initial Results from Optical and Near-Infrared Imaging

    Giavalisco, M., 2004, ApJ

    1,666 citations

  6. X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue

    Buchner, J., 2014, A&A

    1,632 citations

  7. Chandra Sample of Nearby Relaxed Galaxy Clusters: Mass, Gas Fraction, and Mass-Temperature Relation

    Vikhlinin, A., 2006, ApJ

    1,320 citations

  8. Cosmological Evolution of the Hard X-Ray Active Galactic Nucleus Luminosity Function and the Origin of the Hard X-Ray Background

    Ueda, Yoshihiro, 2003, ApJ

    1,088 citations

  9. Chandra Cluster Cosmology Project III: Cosmological Parameter Constraints

    Vikhlinin, A., 2009, ApJ

    1,015 citations

  10. VISTA Variables in the Via Lactea (VVV): The public ESO near-IR variability survey of the Milky Way

    Minniti, D., 2010, NewA

    994 citations

  11. A Systematic Study of Radio-induced X-Ray Cavities in Clusters, Groups, and Galaxies

    Bîrzan, L., 2004, ApJ

    885 citations

  12. The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era

    Gilli, R., 2007, A&A

    858 citations

  13. Constraints on dark energy from Chandra observations of the largest relaxed galaxy clusters

    Allen, S. W., 2004, MNRAS

    816 citations

  14. Chandra X-Ray Spectroscopic Imaging of Sagittarius A* and the Central Parsec of the Galaxy

    Baganoff, F. K., 2003, ApJ

    808 citations

  15. Infrared Luminosity Functions from the Chandra Deep Field-South: The Spitzer View on the History of Dusty Star Formation at 0 <~ z <~ 1

    Le Floc'h, Emeric, 2005, ApJ

    804 citations

  16. Shocks and cold fronts in galaxy clusters

    Markevitch, Maxim, 2007, PhR

    777 citations

  17. The Chandra Deep Field North Survey. XIII. 2 Ms Point-Source Catalogs

    Alexander, D. M., 2003, AJ

    761 citations

  18. Compact Object Modeling with the StarTrack Population Synthesis Code

    Belczynski, Krzysztof, 2008, ApJS

    761 citations

  19. Detection of an Unidentified Emission Line in the Stacked X-Ray Spectrum of Galaxy Clusters

    Bulbul, Esra, 2014, ApJ

    758 citations

  20. An Overview of the Performance and Scientific Results from the Chandra X-Ray Observatory

    Weisskopf, M. C., 2002, PASP

    711 citations

How we found these papers

We searched NASA’s Astrophysics Data System (ADS) for peer-reviewed articles naming Chandra in the title, abstract or keywords; standard filters drop articles that are not peer-reviewed and magazine pieces. SciX is ADS’s current interface.

((=abs:"Chandra X-ray" OR =abs:"Chandra observations" OR =abs:"Chandra observation" OR =abs:"Chandra data" OR (abs:Chandra AND (=abs:"X-ray" OR =abs:"X-rays" OR =abs:xray OR =abs:xrays) AND NOT (abs:Chandrayaan OR abs:Chandrayan OR =abs:"Himalayan Chandra Telescope")) OR (abs:Chandra AND collection:astronomy AND NOT (=abs:"Himalayan Chandra Telescope" OR =abs:"Harish-Chandra" OR =abs:"Harish Chandra" OR =abs:"Chandra Wickramasinghe" OR abs:Chandrayaan OR abs:Chandrayan OR abs:glacier OR abs:glaciers OR =abs:"Chandra basin" OR =abs:"Chandra valley")) OR ((abs:ACIS OR abs:HETG OR abs:HETGS OR abs:LETG OR abs:LETGS OR abs:CXO) AND (=abs:"X-ray" OR =abs:"X-rays" OR =abs:xray OR =abs:xrays) AND collection:astronomy) OR (abs:HRC AND (abs:ACIS OR abs:HETG OR abs:HETGS OR abs:LETG OR abs:LETGS)) OR =abs:"Advanced CCD Imaging Spectrometer" OR =abs:"High Energy Transmission Grating" OR =abs:"High Energy Transmission Gratings" OR =abs:"Low Energy Transmission Grating" OR =abs:"Low Energy Transmission Gratings" OR facility:CXO OR facility:Chandra)) AND property:refereed AND doctype:article AND pubdate:[1999-09 TO 2040-01] AND NOT bibstem:("A&R" OR "AIASJ" OR "AeAm" OR "AirSp" OR "AsNow" OR "AsUAI" OR "AvWST" OR "C&E" OR "C&T" OR "CAPJ" OR "E&S" OR "ENews" OR "IrAJ" OR "JCos" OR "JRASC" OR "LAstr" OR "MNSSA" OR "Met" OR "NewSc" OR "Orion" OR "PhT" OR "PhTea" OR "PhuZ" OR "PhyOJ" OR "PhyW" OR "PlR" OR "SciAm" OR "SpFl" OR "ZemVs")

Open in SciX

Added after review (2)

  1. Accurate X-ray position and multiwavelength observations of the isolated neutron star RBS1774 X-ray position of RBS1774 from a Chandra High Resolution Camera observation. Decision 🤖
  2. Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions Cassiopeia A simulations analysing Chandra and NuSTAR observations of the ejecta. Decision 🤖

Removed after review (4)

  1. Type-Ia Supernova Rates and the Progenitor Problem: A Review "Sub-Chandra" refers to sub-Chandrasekhar-mass white dwarfs, not the observatory. Decision 🤖
  2. Technology developments needed for future X-ray astronomy missions Technology needs for future X-ray missions; mentions Chandra only as a predecessor. Decision 🤖
  3. Soft X-ray performance of an optimised charge-coupled device for astronomy Ground tests of a CCD for the SMILE mission; mentions Chandra only for comparison. Decision 🤖
  4. The NewAthena mission concept in the context of the next decade of X-ray astronomy Mission concept for ESA's NewAthena X-ray observatory; mentions Chandra only as context. Decision 🤖