J/A+A/698/A96ivo://CDS.VizieR/J/A+A/698/A96doi:10.26093/cds/vizier.36980096CDSKanai T.Oasa Y.2025-10-10T20:01:23Z2025-06-04T07:07:26ZCDS support team

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

cds-question@unistra.frstellar-associationspre-main-sequence-starsinfrared-photometryOur aim is to identify the population of very low-mass object (VLMO) candidates in the R CrA region and reveal their formation dependence in the local environments. We performed a deep near-infrared (NIR) photometric observation of the R CrA region by UKIRT/WFCAM. Class I and II candidates showing NIR excess were selected from their observed colors. We derived the photometric mass of each candidate with an age assumption of 1Myr. We compared the derived mass of identified VLMO candidates to the dust column density at their position. The 10{sigma} limiting magnitudes were 20.7, 19.6, and 19.2mag in the J-, H-, and K-band, respectively, and we detected 2922 JHK sources in all three bands with an S/N greater than ten in the K-band. Fifteen Class I and 207 Class II candidates with NIR excess were selected from a [J-H]/[H-K] color-color diagram. Six low-mass stars, five brown dwarfs, and 196 planetary-mass object candidates were identified from the J-band luminosity of Class II candidates with the age assumption of 1 Myr using the evolutionary models. The derived initial mass function (IMF) does not appear to decrease in the brown dwarf and planetary-mass regime, even when taking into account the background star and galactic contamination. From comparison between the spatial distributions of Class I and II candidates and dust column densities derived from the Herschel observation, we found that all the low-mass star and brown dwarf candidates are located in the region where the dust column densities are higher than 2.5x10^21^cm^-2^, while planetary-mass object candidates are independent of their local dust densities. Our results suggest that the formations of low-mass stars and very low-mass objects may be dependent on the local cloud properties.2025A&A...698A..96Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/698/A96CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/698/A96https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/698/A96http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/698/A96https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/698/A96https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/698/A96http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/698/A96GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/698/A96/table2 (JHK catalog of identified objects in the R CrA region with SN>10 at K-band and SN>3 at J- and H-band)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/698/A96/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/698/A96/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/698/A96/table2?GETtext/xml+votable180.050000true285.2313333-36.90463890.0055555555555555566/47825 478281.398457827073138e-19 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/698/A96?format=asciiInfrareddefaultJ/A+A/698/A96/table2JHK catalog of identified objects in the R CrA region with SN>10 at K-band and SN>3 at J- and H-bandrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/2922] Object IDmeta.id;meta.mainintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainJmagWFCAM J magnitudephot.mag;em.IR.Jfloate_JmagWFCAM J magnitude errorstat.errorfloatHmagWFCAM H magnitudephot.mag;em.IR.Hfloate_HmagWFCAM H magnitude errorstat.errorfloatKmagWFCAM K magnitudephot.mag;em.IR.Kfloate_KmagWFCAM K magnitude errorstat.errorfloatJ0mag? J0 magnitudemagphot.mag;em.IR.JfloatnullableClass[1/4] Object Classification (1)meta.code.class;src.classintNHerschel dust column density from HGBScm**-2phys.columnDensitydoubleNameSIMBAD namemeta.idcharRefReference number (2)meta.idchar