J/ApJ/468/633ivo://CDS.VizieR/J/ApJ/468/633doi:10.26093/cds/vizier.14680633CDSHunter D.A.Baum W.A.O'Neil E.J.JrLynds R.1999-02-27T20:36:38Z1999-02-27T21:36:01ZCDS support team

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

cds-question@unistra.frstellar-associationsphotometryAs part of our effort to determine what affects the star formation process by looking at the products of that process, we have obtained broadband Hubble Space Telescope images of the large OB association NGC 206 in the nearby spiral galaxy M31. Our images cover approximately the southern half of the association. We have detected stars down to an F555W magnitude of 25.5 and measure stars on the main sequence in NGC 206 to an M_F555W,0_ of -1 or a mass of ~6M_{sun}_. From a comparison with isochrones, ages up to about 8Myr are plausible, and we adopt an age of 6Myr. For stellar masses 6-15M_{sun}_, we determine an initial mass function slope of -1.4+/-0.5. This is close to the value for a Salpeter mass function, although the uncertainty is large. The uncertainty in the slope represents disagreement among the individual mass bins. In terms of intermediate-mass stars (6-15M_{sun}_) the NGC 206 star formation event appears to be typical of star formation processes in other nearby galaxies, and it is part of a growing number of studies ,that are finding similarities in the products of the star formation processes in a wide variety of star formation events and galactic environments. Nevertheless, the density of stars formed in NGC 206 is much lower than that in giant H II regions such as NGC 604 in M33 or 30 Doradus in the LMC and in typical OB associations.1996ApJ...468..633Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/468/633CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/98/595 : OB associations in M31 (Hill+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/468/633https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/468/633http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/468/633https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/468/633https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/468/633http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/468/633GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapHSTOpticaldefaultJ/ApJ/468/633/table2Cluster photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identification numbermeta.id;meta.mainintxposx pixel coordinate (1)pixpos.cartesian.x;instr.detfloatyposy pixel coordinate (1)pixpos.cartesian.y;instr.detfloatF336W? F336W magnitude (2)magphot.mag;em.opt.Ufloatnullablee_F336W? uncertainty in F336W magnitude (2)magstat.errorfloatnullableF555WF555W magnitudemagphot.mag;em.opt.Vfloate_F555Wuncertainty in F555W magnitudemagstat.errorfloatF814WF814W magnitudemagphot.mag;em.opt.Ifloate_F814Wuncertainty in F814W magnitudemagstat.errorfloatF336W-F555W? F336W-F555W color (2)magphot.color;em.opt.U;em.opt.Vfloatnullablee_F336W-F555W? uncertainty in F336W-F555W color (2)magstat.errorfloatnullableF555W-F814WF555W-F814W colormagphot.color;em.opt.V;em.opt.Ifloate_F555W-F814Wuncertainty in F555W-F814W colormagstat.errorfloatJ/ApJ/468/633/table3Background field photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identification numbermeta.id;meta.mainintxposx pixel coordinate (1)pixpos.cartesian.x;instr.detfloatyposy pixel coordinate (1)pixpos.cartesian.y;instr.detfloatF336W? F336W magnitude (2)magphot.mag;em.opt.Ufloatnullablee_F336W? uncertainty in F336W magnitude (2)magstat.errorfloatnullableF555WF555W magnitudemagphot.mag;em.opt.Vfloate_F555Wuncertainty in F555W magnitudemagstat.errorfloatF814WF814W magnitudemagphot.mag;em.opt.Ifloate_F814Wuncertainty in F814W magnitudemagstat.errorfloatF336W-F555W? F336W-F555W color (2)magphot.color;em.opt.U;em.opt.Vfloatnullablee_F336W-F555W? uncertainty in F336W-F555W color (2)magstat.errorfloatnullableF555W-F814WF555W-F814W colormagphot.color;em.opt.V;em.opt.Ifloate_F555W-F814Wuncertainty in F555W-F814W colormagstat.errorfloat