J/ApJ/960/49ivo://CDS.VizieR/J/ApJ/960/49CDSRobberto M.Gennaro M.Da Rio N.Strampelli G.M.Ubeda L.Sabbi E.,Koeppe D.Tan J.C.Soderblom D.R.2026-05-04T07:43:19Z2026-04-14T08:08:48ZCDS support team

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

cds-question@unistra.fropen-star-clustershst-photometryinfrared-sourcesstellar-massesextinctionyoung-stellar-objectsWe performed an HST/WFC3-IR imaging survey of the young stellar cluster NGC 2024 in three filters probing the 1.4{mu}m H2O absorption feature, characteristic of the population of low-mass and substellar-mass objects down to a few Jupiter masses. We detect 812 point sources, 550 of them in all three filters with signal-to-noise ratio greater than 5. Using a distance-independent two-color diagram, we determine extinction values as high as A_V_~40. We also find that the change of effective wavelengths in our filters results in higher AV values as the reddening increases. Reconstructing a dereddened color-magnitude diagram, we derive a luminosity histogram both for the full sample of candidate cluster members and for an extinction-limited subsample containing the 50% of sources with A_V_<~15. Assuming a standard extinction law like Cardelli+ 1989ApJ...345..245C with a nominal R_V_=3.1, we produce a luminosity function in good agreement with the one resulting from a Salpeter-like initial mass function for a 1 Myr isochrone. There is some evidence of an excess of luminous stars in the most embedded region. We posit that the correlation may be due to those sources being younger, and therefore overluminous, than the more evolved and less extincted cluster's stars. We compare our classification scheme based on the depth of the 1.4{mu}m photometric feature with the results from the spectroscopic survey of Levine+ 2006, J/ApJ/646/1215, and we report a few peculiar sources and morphological features typical of the rich phenomenology commonly encountered in young star-forming regions.2024ApJ...960...49Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/960/49CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/AJ/126/1665 : NICMOS observations of NGC 2024 (Liu+, 2003)J/ApJ/598/375 : Chandra X-ray observations of NGC 2024 (Skinner+, 2003)J/ApJ/646/1215 : Low-mass stars and brown dwarfs in NGC 2024 (Levine+, 2006)J/ApJS/173/104 : Stellar population in Chamaeleon I (Luhman, 2007)J/A+A/536/A63 : Collinder 69 very low mass stars and BDs (Bayo+, 2011)J/ApJ/754/30 : VISTA IR phot. of {sigma} Ori cluster (Pena Ramirez+, 2012)J/MNRAS/431/3222 : UKIDSS GCS Upper Sco members (Lodieu, 2013)J/MNRAS/444/1793 : 25 Ori group low-mass stars (Downes+, 2014)J/ApJ/787/109 : Age estimates for NGC 2024 and ONC stars (Getman+, 2014J/MNRAS/463/2653 : 8620 DIB equivalent width and extinction (Damineli+, 2016)J/MNRAS/486/1718 : System IMF of 25 Ori (Suarez+, 2019)J/ApJ/896/79 : HST survey of ONC in H20 1.4um abs. I. (Robberto+, 2020)J/A+A/640/A27 : Protoplanetary disk masses in NGC 2024 (van Terwisga+, 2020)J/A+A/666/A113 : Stellar integrated gal. initial mass function (Dib, 2022)J/A+A/677/A26 : (sub)stellar members of NGC 2244 sp. (Almendros-Abad+, 2023)J/ApJ/951/139 : W filter YSOs detection. VI. sigma Orionis (Damian+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/960/49https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/960/49http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/960/49https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/960/49https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/960/49http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/960/49GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/960/49/table2 (WFC3-IR photometry from the HST GO-15334 program)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/960/49/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/960/49/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/960/49/table2?GETtext/xml+votable180.050000true85.396685-2.008753060.0055555555555555566/228551.4021468880710216e-19 2.1189193140583396e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/960/49?format=asciiInfrareddefaultJ/ApJ/960/49/table2WFC3-IR photometry from the HST GO-15334 programrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMmDisplay the extinction and mass of this candidate cluster member (link to Table 3)meta.ref.urlcharSeq[1/812] Sequential identifiermeta.id;meta.mainintprimaryRAJ2000[85.3/85.6] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-2.1/-1.8] Declination (J2000)degpos.eq.dec;meta.mainF105Wmag[12.43/29.3]? HST/WFC3 F105W filter magnitude (Vega mag) (1)magphot.mag;em.IR.Jfloatnullablee_F105Wmag[0/1.4]? F105Wmag uncertainty (1)magstat.error;phot.mag;em.IR.JfloatnullableF130Nmag[9.98/25.9]? HST/WFC3 F130N filter magnitude (Vega mag) (1)magphot.mag;em.IR.Jfloatnullablee_F130Nmag[0/0.4]? F130Nmag uncertainty (1)magstat.error;phot.mag;em.IR.JfloatnullableF139Mmag[9.89/23.2]? HST/WFC3 F139M filter magnitude (Vega mag) (1)magphot.mag;em.IR.Jfloatnullablee_F139Mmag[0/0.4]? F139Mmag uncertainty (1)magstat.error;phot.mag;em.IR.JfloatnullableJ/ApJ/960/49/table3Extinction and mass of candidate cluster membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/809] Sequential identifiermeta.id;meta.mainintAv[-5.25/42.9]? Visual extinction (1)magphys.absorptionfloatnullableMstar[0.003/1.4]? Stellar masssolMassphys.massfloatnullable