ZWCLUSTERS - Zwicky Clusters
The ZWCLUSTERS database is based upon the Catalogue of Zwicky Clusters
of Galaxies. The Zwicky clusters were identified by F. Zwicky in 560
POSS fields. They are rich clusters, each having at least 50 members
within 3 magnitudes of the brightest member.
Zwicky, F., et al., 1961-68, Catalogue of Galaxies and of Clusters of Galaxies
(Pasadena, California Institute of Technology, 6 vols.).
Designation derived from the Zwicky cluster number. Cluster number
(1...9134). This file is in ascending order by B1950.0 right
ascension, whereas the original published catalogue is sorted by the
survey field number and a running number within each survey field.
Right Ascension in 1950 Coordinates
Declination in 1950 Coordinates
The galactic longitude of the object.
The galactic latitude of the object.
Cluster types are 1 for open, 2 for medium compact, or 3 for compact.
The counted number of galaxies in the cluster.
The measured diameter of the cluster in centimeters.
Distance group, as estimated by Zwicky: 1 for near, 2 for medium distant,
3 for distant, 4 for very distant, or 5 for extremely distant.
Lambert coordinates. The Lambert tranformation is an equal-area projection.
The Lambert distance RL from the nearest galactic pole is defined by RL = 2
sin ((90-b)/2), with RL > 0 for the north galactic hemisphere, and RL < 0 for
the south galactic hemisphere.
Lambert coordinates. The X Lambert coordinate XL = 2 sin l sin ((90-b)/2).
Lambert coordinates. The Y Lambert coordinate YL = 2 cos l sin ((90-b)/2).
The supergalactic longitude of the object.
The supergalactic latitude of the object.
The cluster radius in degrees calculated as <clusrad> = 0.09326 * Diameter.
The cluster area in square degrees: 0.02733 * Diameter^2.
The mean apparent population (galaxies per square degree): population/area,
taken from Cluster Pop and Cluster Area
The Right Ascension of the object.
The Declination of the object.
Right Ascension, Sexagesimal, J2000
Declination, Sexagesimal, J2000
BROWSE classification type.
Questions regarding the ZWCLUSTERS database table can be addressed to the
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