J/A+A/626/A35ivo://CDS.VizieR/J/A+A/626/A35doi:10.26093/cds/vizier.36260035CDSRodriguez M.J.Baume G.Feinstein C.2019-09-19T06:44:16Z2019-06-07T06:35:20ZCDS support team

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

cds-question@unistra.frgalaxiesh-ii-regionsyoung-stellar-objectsWe seek to investigate the characteristics of the young stellar population in the spiral galaxy NGC 247. In particular, we focused our attention in its hierarchical clustering distributions and the properties of the smallest groups. We used multiband Hubble Space Telescope (HST) data from three fields covering more than half of NGC 247 to select the young population. Then, through the path linkage criterion (PLC), we found compact young star groups and estimated their fundamental parameters, such as their stellar densities, sizes, number of members, and luminosity function (LF) slopes. We also performed a fractal analysis to determinate the clustering properties of this population. We built a stellar density map and dendrograms corresponding to the galactic young population to detect large structures and depict their main characteristics. We detect 339 young star groups, for which we compute a mean radius of ~60pc and a maximum size distribution between 30 and 70pc. We also obtain LF slopes with a bimodal distribution showing peaks at ~0.1 and ~0.2. We identify several candidates for HII regions that follow an excellent spatial correlation with the young groups found by the PLC. We observe that the young populations are hierarchically organized, wherein the smaller and denser structures are within larger and less dense structures. We notice that all these groups present a fractal subclustering, following the hierarchical distribution observed in the corresponding stellar density map. For the large young structures observed in this map, we obtain a fractal dimension of ~1.6-1.8 using the perimeter-area relation and cumulative size distribution. These values are consistent with a scenario of hierarchical star formation.2019A&A...626A..35Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/626/A35CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/136/1770 : VI light curves of NGC 247 Cepheids (Garcia-Varela+, 2008)J/ApJ/694/1237 : BVRI light curves of NGC 247 Cepheids (Madore+, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/626/A35https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/626/A35http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/626/A35https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/626/A35https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/626/A35http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/626/A35GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/626/A35/table3 (Main parameters of young stellar groups in NGC 247)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/626/A35/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/626/A35/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/626/A35/table3?GETtext/xml+votable180.050000true11.805643-20.8612430.005555555555555556Cone search capability for table J/A+A/626/A35/table4 (Candidates to HII regions)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/626/A35/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/626/A35/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/626/A35/table4?GETtext/xml+votable180.050000true11.80575-20.86111110.005555555555555556Cone search capability for table J/A+A/626/A35/list (Information on fits image)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/626/A35/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/626/A35/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/626/A35/list?GETtext/xml+votable180.050000true11.76759-20.819710.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/626/A356/167012.76124552865182e-19 3.9057996558789745e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/626/A35?format=asciidefaultJ/A+A/626/A35/table3Main parameters of young stellar groups in NGC 247NameIdentification (ASNNN)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainDistGCGalactocentric distancekpcpos.distancefloatRadiusRadiuspcphys.size.radiusfloatNgNumber of stars inside the group radiusmeta.numberintNbgNumber of bright blue stars inside the group radiusmeta.numberintNdNumber of stars after field decontaminationmeta.numberintNbdNumber of bright blue stars after field decontaminationmeta.numberintF606WmagF606W value of the brightest blue starmagphot.mag;em.opt.RfloatrhoStellar density in stars/pc^3^pc**-3phys.densitydoubleGamma? Luminosity function slopearith.grad;phys.luminosity.funfloatnullablee_Gamma? Luminosity function slope errorstat.errorfloatnullablemMean edge length in a minimum spanning treestat.fit.paramfloate_mError of mstat.errorfloatsMean separation of the stars in the groupstat.fit.paramfloate_sError of sstat.errorfloatQQ parameterphot.color.reddFreefloate_QError of the Q parameterstat.errorfloatJ/A+A/626/A35/table4Candidates to HII regionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/23] Identification numbermeta.id;meta.mainintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declinaiton (J2000)pos.eq.dec;meta.mainDiamDiameterarcminphys.angSizefloatJ/A+A/626/A35/listInformation on fits imagerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar