J/A+A/288/413ivo://CDS.VizieR/J/A+A/288/413doi:10.26093/cds/vizier.32880413CDSDeharveng J.-M.Albrecht R.Barbieri C.Blades J.C.Boksenberg A.,Crane P.Disney M.J.Jakobsen P.Kamperman T.M.King I.R.,Macchetto F.Mackay C.D.Paresce F.Weigelt G.Baxter D.,Greenfield P.Jedrzejewski R.Nota A.Sparks W.B.1997-12-09T16:21:52Z1997-12-09T17:21:49ZCDS support team

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

cds-question@unistra.frultraviolet-photometrystellar-populationsWe have observed the blue dwarf galaxy I Zw 36 with the f/96 relay of the HST Faint Object Camera and have for the first time resolved massive stars, using the broad band filters F175W, F342W, F430W and F480LP. We have measured the fluxes of 143 of these objects and studied their characteristics in color-magnitude diagrams. A few stars may be red supergiants but their contribution to the integrated light is less than 5% in the F430W filter. The F175W-F430W color of the integrated stellar population is redder than expected from the current burst of star formation, suggesting therefore the presence of an older and unresolved underlying population. The ultraviolet measurements combined with synthetic photometry calculations allow us to place the massive stars in a bolometric magnitude vs. temperature diagram. In this diagram, the stars are compared to evolutionary tracks for different stellar masses. The current burst probably has an age less than 12Myr. We infer an Initial Mass Function, with a power-law slope in the range -1.7 to -2.6 for masses M>=20M_{sun}_. This is consistent with most of the values reported for sites of star formation in the Galaxy and the Magellanic Clouds and does not support the view of an IMF flattening at low metallicity.1994A&A...288..413Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/288/413CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/288/413https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/288/413http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/288/413https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/288/413https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/288/413http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/288/413GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapHSTUVdefaultJ/A+A/288/413/table1Photometry of starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification numbermeta.id;meta.mainintXposX position (1)pixpos.cartesian.x;instr.detfloatYposY position (1)pixpos.cartesian.y;instr.detfloatm175? Magnitude through the F175W filtermagphot.mag;em.UV.100-200nmfloatm342? Magnitude through the F342W filtermagphot.mag;em.opt.Ufloatm430Magnitude through the F430W filtermagphot.mag;em.opt.Bfloat