J/A+A/553/A87ivo://CDS.VizieR/J/A+A/553/A87doi:10.26093/cds/vizier.35530087CDSDrazinos P.Kontizas E.Karampelas A.Kontizas M.Dapergolas A.2014-07-20T21:51:19Z2014-02-18T14:17:30ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiescatalogsgalaxy-classification-systemsThe presence of small- and large-scale star formation structures in a sample of six spiral Hubble Space Telescope (HST) galaxies is investigated to identify small structures of young stars known as OB associations and to tell whether they are formed inside larger scale star forming stellar structures in a hierarchical form. This process was based on a friend-of-friend (FOF) algorithm applied to the bright, early type stars above a certain color cutoff limit in order to ensure that we include main sequence stars. A size criterion was introduced in order to apply the same algorithm to different types of stellar structures. Depending on their size, the structures were divided into the four categories of associations, aggregates, complexes, and supercomplexes. Star forming structures of the four types mentioned above are found in all six galaxies of our sample. The majority of the associations and aggregates (the smaller structures) found are lying inside larger structures like complexes and supercomplexes, indicating a hierarchical star formation mechanism.2013A&A...553A..87Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/553/A87CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/553/A87https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/553/A87http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/553/A87https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/553/A87https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/553/A87http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/553/A87GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/553/A87/groups (Young stellar structures in the 6 galaxies studied)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/553/A87/groups?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/553/A87/groups?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/553/A87/groups?GETtext/xml+votable180.050000true36.7734138933.5830550.0055555555555555566/2320 6619 11434 27514 27942 38390https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/553/A87?format=asciiOpticaldefaultJ/A+A/553/A87/groupsYoung stellar structures in the 6 galaxies studiedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNGCNGC number of parent galaxymeta.id.parentintnullableIndexSequential number within the Groupmeta.idintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainNstarsNumber of stars in Groupmeta.numberintSizeGroup size (parsec)pcphys.size.radiusdoubleType[1/4] Type of Group: 1=Association, 2=Aggregate, 3=Complex, 4=Supercomplexmeta.codeint