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ZWICLU : ZWICKY Catalogue of clusters of galaxies

Contents

Table name: 	ZWICLU
Records:  	9134
Spectral Band: 	OPT
Kind of Object: Cluster of Galaxies
Mode: 		General
PreView:
Coordinates: 	B1950

Reference

Description

This catalogue contains a list of cluster of galaxies to the limit of the 48 inch Scmidt telescope on the Palomar Mountain. It includes only rich clusters containing at least 50 galaxies in the luminosity range from m_max to m_max+3 where m_max is the apparent photographic magnitude of the brightest galaxy in the cluster. The positions are given to the nearest minute of arc in declination and to the nearest tenth of a minute of time in right ascension. The distance classes are classified as follows : The population of a cluster is the number of galaxies actually counted within the outline of that cluster as given on the chart minus the estimated number of background galaxies in the same area.

The diameter of the cluster is defined as that of a circle overing approximately the same area as the cluster on the original Survey plate.

Fields

Name	Type	Meaning

number	I	Order number
r_a	I	Right Ascension
dec	I	Declination
type	I	Type:

		1 : open cluster
		2 : medium compact cluster
		3 : compact cluster

pop	I	Population in number of galaxies
diam	F	Diameter in cm. on the PSS plate
dist	I	Distance class (see above)
nf1	I	identification : field number
n1	I	" : cluster number
nf2	I	identification : field number
n2	I	" : cluster number
nf3	I	identification : field number
n3	I	" : cluster number
nf4	I	identification : field number
n4	I	" : cluster number

Derived Quantities

_diam	F	Diameter in '
_ra	F	J2000 Right Ascension
_de	F	J2000 Declination
_lii	F	Galactic Longitude
_bii	F	Galactic Latitude
_L	F	SuperGalactic Longitude
_B	F	SuperGalactic Latitude