J/A+A/677/A26ivo://CDS.VizieR/J/A+A/677/A26doi:10.26093/cds/vizier.36770026CDSAlmendros-Abad V.Muzic K.Bouy H.Bayo A.Scholz A.Pena Ramirez K.,Moitinho A.Kubiak K.Schoedel R.Barac R.Brcic P.Ascenso J.,Jayawardhana R.2026-01-20T12:11:39Z2023-08-29T08:20:07ZCDS support team

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

cds-question@unistra.fropen-star-clusterspre-main-sequence-starsinfrared-astronomyspectroscopyThe dominant formation channel of brown dwarfs (BDs) is not well constrained yet and a promising way to discriminate between scenarios consists of testing environment-dependent efficiency in forming BDs. So far, the outcome of star formation, studied through the initial mass function, has been found to be very similar in all clusters that have been studied. We aim to characterize the low-mass (sub)stellar population of the central portion (2.4pc^2^) of the ~2Myr old cluster NGC 2244 using near-infrared spectroscopy. By studying this cluster, characterized by a low stellar density and numerous OB stars, we aim to explore the effect that OB stars may have on the production of BDs. We obtained near-infrared HK spectroscopy of 85 faint candidate members of NGC 2244. We derived the spectral type and extinction by comparison with spectral templates. We evaluated cluster membership using three gravity-sensitive spectral indices based on the shape of the H-band. Furthermore, we evaluated the infrared excess from Spitzer of all the candidate members of the cluster. Finally, we estimated the mass of all the candidate members of the cluster and derived the initial mass function, star-to-BD number ratio and disk fraction. The initial mass function is well represented by a power law (dN/dM {prop.to} M^-alpha^) below 0.4M_{sun}_, with a slope alpha=0.7-1.1 depending on the fitted mass range. We calculated a star-to-BD number ratio of 2.2-2.8. We find the low-mass population of NGC 2244 to be consistent with nearby star- forming regions, although it is at the high end of BD production. We find BDs in NGC 2244 to be, on average, closer to OB stars than to low-mass stars, which could potentially be the first piece evidence that OB stars affect the formation of BDs. We find a disk fraction of all the members with a spectral type later than K0 of 39+/-9% which is lower than typical values found in nearby star-forming regions of similar ages.2023A&A...677A..26Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/677/A26CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/836/34 : 24um excesses in clusters + membership of NGC2244 (Meng+, 2017)J/ApJ/881/79 : Flamingos-2 near-infrared photometry in NGC2244 (Muzic+, 2019)J/A+A/668/A19 : Stellar population of Rosette Nebula and NGC2244 (Muzic+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/677/A26https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/677/A26http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/677/A26https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/677/A26https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/677/A26http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/677/A26GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/677/A26/table2 (Properties of the observed KMOS objects with late SpType spectroscopic shape)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/677/A26/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/677/A26/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/677/A26/table2?GETtext/xml+votable180.050000true97.960734.958130.005555555555555556Cone search capability for table J/A+A/677/A26/tabled1 (Membership analysis of all the members and candidate members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/677/A26/tabled1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/677/A26/tabled1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/677/A26/tabled1?GETtext/xml+votable180.050000true97.9614.976610.005555555555555556Cone search capability for table J/A+A/677/A26/list (List of KMOS fits spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/677/A26/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/677/A26/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/677/A26/list?GETtext/xml+votable180.050000true97.961891674.960560.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/677/A266/22249https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/677/A26?format=asciiInfrareddefaultJ/A+A/677/A26/table2Properties of the observed KMOS objects with late SpType spectroscopic shapeLow-g[YN?] Low surface gravity ?meta.codecharE_Mass? Mass error (lower value)solMassstat.error;stat.maxfloatnullablee_Mass? Mass error (upper value)solMassstat.error;phys.massfloatnullablen_Low-gNote on Low-g (1)meta.notecharExcess[Y-N] Infrared excess ?meta.codecharMember[YN?] Member ?meta.code.membercharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource ID ([MSP2019] NGC2244 NNN in Simbad for members in M22)meta.id;meta.mainintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainSpTypeSpectral typesrc.spTypecharAVVisual extinctionmagphys.absorptionfloatSpTindDerived spectral typesrc.spTypecharTeffEffective temperatureKphys.temperature.effectiveintMass? MasssolMassphys.massfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/A+A/677/A26/tabled1Membership analysis of all the members and candidate membersspindicates KMOS spectrummeta.ref.urlcharIDSource ID ([MSP2019] NGC2244 NNN in Simbad for members in M22)meta.id;meta.mainintprimaryRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainSpTypeSpectral type, templatessrc.spTypecharAvVisual extinction, templatesmagphys.absorptionfloatTeff? Effective temperatureKphys.temperature.effectiveintnullableKMOS[YN-] Observed with KMOSmeta.codecharKMOS-grav[YN-?] KMOS gravity-sensitive spectral indices keymeta.codecharVIMOS[YN-] Observed with VIMOSmeta.codecharVIMOS-Ha[YN-] VIMOS H{alpha} emission consistent with accretionmeta.codecharM17[YN-] Membership in Meng et al. (2017ApJ...836...34M, Cat. J/ApJ/836/34)meta.codecharM22[YN-] Membership in Muzic et al. (2022A&A...668A..19M, Cat. J/A+A/668/A19)meta.codecharExcess[YN-] Infrared excessmeta.codecharMember[YN-?] Membership to NGC 2244meta.code.membercharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/A+A/677/A26/listList of KMOS fits spectraIDSource IDmeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainSpTypeSpectral type, templatessrc.spTypecharAvVisual extinction, templatesmagphys.absorptionfloatMemberMembership to NGC 2244meta.code.membercharspShow the sepctrummeta.ref.urlcharFileNameName of the spectrum fits file in subdirectory fitsmeta.id;meta.fitschar