<?xml-stylesheet href='/static/xsl/oai.xsl' type='text/xsl'?>
<ri:Resource created="2026-04-03T00:00:00" status="active" updated="2026-04-03T00:00:00" version="1.2" xmlns:cs="http://www.ivoa.net/xml/ConeSearch/v1.0" xmlns:ri="http://www.ivoa.net/xml/RegistryInterface/v1.0" xmlns:stc="http://www.ivoa.net/xml/STC/stc-v1.30.xsd" xmlns:vr="http://www.ivoa.net/xml/VOResource/v1.0" xmlns:vs="http://www.ivoa.net/xml/VODataService/v1.1" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ivoa.net/xml/ConeSearch/v1.0 http://vo.ari.uni-heidelberg.de/docs/schemata/ConeSearch.xsd http://www.ivoa.net/xml/STC/stc-v1.30.xsd http://vo.ari.uni-heidelberg.de/docs/schemata/stc-v1.30.xsd http://www.ivoa.net/xml/VOResource/v1.0 http://vo.ari.uni-heidelberg.de/docs/schemata/VOResource.xsd http://www.ivoa.net/xml/VODataService/v1.1 http://vo.ari.uni-heidelberg.de/docs/schemata/VODataService.xsd http://www.w3.org/1999/xlink http://vo.ari.uni-heidelberg.de/docs/schemata/xlink.xsd" xsi:type="vs:CatalogService">
  <title>Zwicky Clusters</title>
  <shortName>Zwicky</shortName>
  <identifier>ivo://nasa.heasarc/zwclusters</identifier>
  <curation>
    <publisher ivo-id="ivo://nasa.heasarc/ASD">NASA/GSFC HEASARC</publisher>
    <creator>
      <name>Zwicky, Herzog, Wild</name>
    </creator>
    <contributor/>
    <date>2026-04-03</date>
    <contact>
      <name>NASA/GSFC HEASARC help desk</name>
      <email>heasarc-vo at athena.gsfc.nasa.gov</email>
    </contact>
  </curation>
  <content>
    <subject>Cluster of Galaxies</subject>
    <description>
      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. This is a service provided by NASA HEASARC .
    </description>
    <source format="">
      1961CGCG..C......0Z
    </source>
    <referenceURL>https://heasarc.gsfc.nasa.gov/W3Browse/all/zwclusters.html</referenceURL>
    <type>Catalog</type>
    <contentLevel>Research</contentLevel>
    <relationship>
      <relationshipType>
        served-by
      </relationshipType>
      <relatedResource ivo-id="ivo://nasa.heasarc/services/xamin">
        HEASARC TAP
      </relatedResource>
    </relationship>
  </content>
  <capability standardID="ivo://ivoa.net/std/ConeSearch" xsi:type="cs:ConeSearch">
    <interface role="std" xsi:type="vs:ParamHTTP">
      <accessURL use="base">
        https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&amp;table=zwclusters&amp;
      </accessURL>
      <queryType>GET</queryType>
      <resultType>text/xml</resultType>
    </interface>
    <maxSR>180</maxSR>
    <maxRecords>99999</maxRecords>
    <verbosity>true</verbosity>
    <testQuery>
      <ra>72.944</ra>
      <dec>-4.534</dec>
      <sr>0.25</sr>
    </testQuery>
  </capability>
  <capability standardID="ivo://ivoa.net/std/TAP#aux">
    <interface xsi:type="vs:ParamHTTP" role="std">
      <accessURL use="base">
        https://heasarc.gsfc.nasa.gov/xamin/vo/tap
      </accessURL>
    </interface>
  </capability>
  <capability>
    <interface xsi:type="vs:ParamHTTP">
      <accessURL use="base">
        https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=zwclusters
      </accessURL>
      <queryType>GET</queryType>
      <resultType>text/xml</resultType>
    </interface>
  </capability>
  <capability>
    <interface xsi:type="vr:WebBrowser">
      <accessURL use="full">
        https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_zwclusters&amp;Action=More+Options&amp;Action=Parameter+Search&amp;ConeAdd=1
      </accessURL>
    </interface>
  </capability>
  <facility>GALAXY CATALOG</facility>
  <coverage>
    <stc:STCResourceProfile>
      <stc:AstroCoordSystem xlink:type="simple" xlink:href="ivo://STClib/CoordSys#UTC-ICRS-TOPO" id="_zwclusters_UTC-ICRS-TOPO2da629cd0f902b7d37e41c067ea39b9a"/>
      <stc:AstroCoords coord_system_id="_zwclusters_UTC-ICRS-TOPO2da629cd0f902b7d37e41c067ea39b9a">
        <stc:Position1D>
          
          <stc:Size pos_unit="deg">
            0.25
          </stc:Size>
        </stc:Position1D>
      </stc:AstroCoords>
      <stc:AstroCoordArea coord_system_id="_zwclusters_UTC-ICRS-TOPO2da629cd0f902b7d37e41c067ea39b9a">
        <stc:AllSky/>
      </stc:AstroCoordArea>
    </stc:STCResourceProfile>
    <waveband>Optical</waveband>
  </coverage>
  <tableset xsi:type="vs:TableSet">
    <schema>
      <name>public</name>
      <table>
        <name>zwclusters</name>
        <description>
          Zwicky Clusters
        </description>
        <column>
          <name>sglon</name>
          <description>
            Super-Galactic Longitude
          </description>
          <unit>degree</unit>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>"__row"</name>
          <description>
            System index column
          </description>
          <dataType xsi:type="vs:VOTableType">char</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>cluster_type</name>
          <description>
            Cluster Type
          </description>
          <dataType xsi:type="vs:VOTableType">char</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>lamb_y</name>
          <description>
            Y Lambert Coordinate (YL)
          </description>
          <dataType xsi:type="vs:VOTableType">float</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>"__x_ra_dec"</name>
          <description>
            System unit vector column
          </description>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>cluster_area</name>
          <description>
            Cluster Area
          </description>
          <unit>degree^2</unit>
          <dataType xsi:type="vs:VOTableType">float</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>ra_1950</name>
          <description>
            Right Ascension in 1950 Coordinates
          </description>
          <unit>degree</unit>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>lii</name>
          <description>
            Galactic Longitude
          </description>
          <unit>degree</unit>
          <ucd>
            pos.galactic.lon
          </ucd>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>lamb_distance</name>
          <description>
            Lambert Distance (RL)
          </description>
          <dataType xsi:type="vs:VOTableType">float</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>"__y_ra_dec"</name>
          <description>
            System unit vector column
          </description>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>cra</name>
          <description>
            Right Ascension, Sexagesimal, J2000
          </description>
          <dataType xsi:type="vs:VOTableType">char</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>ra</name>
          <description>
            Right Ascension, J2000
          </description>
          <unit>degree</unit>
          <ucd>
            pos.eq.ra;meta.main
          </ucd>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>sglat</name>
          <description>
            Super-Galactic Latitude
          </description>
          <unit>degree</unit>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>cdec</name>
          <description>
            Declination, Sexagesimal, J2000
          </description>
          <dataType xsi:type="vs:VOTableType">char</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>dist_group</name>
          <description>
            Distance Group
          </description>
          <dataType xsi:type="vs:VOTableType">short</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>cluster_radius</name>
          <description>
            Cluster Radius
          </description>
          <unit>degree</unit>
          <dataType xsi:type="vs:VOTableType">float</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>mean_pop</name>
          <description>
            Mean Apparent Population
          </description>
          <dataType xsi:type="vs:VOTableType">short</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>"__z_ra_dec"</name>
          <description>
            System unit vector column
          </description>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>class</name>
          <description>
            Browse Object Classification
          </description>
          <ucd>
            src.class
          </ucd>
          <dataType xsi:type="vs:VOTableType">short</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>lamb_x</name>
          <description>
            X Lambert Coordinate (XL)
          </description>
          <dataType xsi:type="vs:VOTableType">float</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>bii</name>
          <description>
            Galactic Latitude
          </description>
          <unit>degree</unit>
          <ucd>
            pos.galactic.lat
          </ucd>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>cluster_pop</name>
          <description>
            Population of Cluster
          </description>
          <dataType xsi:type="vs:VOTableType">short</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>diameter</name>
          <description>
            Diameter of Cluster
          </description>
          <unit>cm</unit>
          <dataType xsi:type="vs:VOTableType">float</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>name</name>
          <description>
            Object Designation
          </description>
          <ucd>
            meta.id;meta.main
          </ucd>
          <dataType xsi:type="vs:VOTableType">char</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>dec_1950</name>
          <description>
            Declination in 1950 Coordinates
          </description>
          <unit>degree</unit>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
        <column>
          <name>dec</name>
          <description>
            Declination, J2000
          </description>
          <unit>degree</unit>
          <ucd>
            pos.eq.dec;meta.main
          </ucd>
          <dataType xsi:type="vs:VOTableType">double</dataType>
          <flag>
            nullable
          </flag>
        </column>
      </table>
    </schema>
  </tableset>
</ri:Resource>