Hickson Compact Groups of Galaxies (HCG) Individual Galaxies Data

The HCGGALAXY database table is based on the Hickson Catalog of Compact Groups, and contains data on 463 galaxies in 100 compact groups of galaxies that were identified by a systematic search of the Palomar Observatory Sky Survey red prints. Each group contains four or more galaxies, has an estimated mean surface brightness brighter than 26.0 magnitude per arcsec<sup>2</sup> and satisfies an isolation criterion. Astrometry, photometry, and morphological types, derived from CCD images, are presented for the 463 galaxies. Radial velocities are given for 457 of the 463 galaxies: more than 84% of the galaxies measured have radial velocities that are within 1000 km/s of the group median velocity. Morphological information derived from either an isophotal analysis or from a visual inspection of images is given for 210 of the 463 galaxies. This database table essentially contains the information given in Table 2 of Hickson, P. et al. (1989, ApJS, 70, 687), Table 2 of Hickson, P. et al. (1992, ApJ, 399, 353), and Table 2 of Mendes de Oliveira, C. and Hickson, P. (1994, ApJ, 427, 684). Consequently, the information on the properties of the Hickson Compact Groups as units that is also given in some of these references, e.g., in Table 3 of Hickson, P. et al. (1992, ApJ, 399, 353), is not in the HCGGALXY database table; however, the latter data can be found in the related HEASARC database table HCG. This database table was created by the HEASARC in August, 1999, based on machine-readable tables obtained from the ADC/CDS data centers (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/213">CDS catalog VII/213</a>, files galaxies.dat and morpho.dat). The HEASARC added Galactic coordinates and updated the table's metadata in August, 2005. This is a service provided by NASA HEASARC .

Data and Resources

Additional Info

Field Value
Maintainer HEASARC Help Desk
Last Updated September 14, 2026, 22:13 (UTC)
Created April 1, 2025, 12:42 (UTC)
accessLevel public
bureauCode {026:00}
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
harvest_object_id b742819b-eb54-4e42-8520-d64069a431e5
harvest_source_id b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title Science Discovery Engine
identifier ivo://nasa.heasarc/hcggalaxy
landingPage ivo://nasa.heasarc/hcggalaxy
license https://www.usa.gov/government-works
modified 2026-09-07T22:15:59Z
programCode {026:000}
publisher High Energy Astrophysics Science Archive Research Center
resource-type Dataset
source_datajson_identifier true
source_hash 604fc1297b5c1443b033775ee9865e73cf290bf1bd5a6174db18dcf2720b4649
source_schema_version 1.1
theme {Astrophysics}