J/A+A/690/A371ivo://CDS.VizieR/J/A+A/690/A371doi:10.26093/cds/vizier.36900371CDSLibralato M.Gerasimov R.Bedin L.Anderson J.Apai D.Bellini A.,Burgasser A. J.Griggio M.Nardiello D.Salaris M.Scalco M.,Vesperini E.2025-02-24T20:02:14Z2024-10-23T07:38:13ZCDS support team

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

cds-question@unistra.frglobular-star-clustersinfrared-photometryvisible-astronomyWe present observations of the two closest globular clusters, NGC 6121 and NGC 6397, taken with the NIRISS detector of JWST. The combination of our new JWST data with archival Hubble Space Telescope (HST) images allows us to compute proper motions, disentangle cluster members from field objects, and probe the main sequence (MS) of the clusters down to <0.1M_{sun}_ as well as the brighter part of the white-dwarf sequence. We show that theoretical isochrones fall short in modeling the low-mass MS and discuss possible explanations of the observed discrepancies. Our analysis suggests that the lowest-mass members of both clusters are significantly more metal-rich and oxygen-poor than their higher-mass counterparts. It is unclear if the difference is caused by a genuine mass-dependent chemical heterogeneity, low-temperature atmospheric processes altering the observed abundances, or systematic shortcomings in the models. We computed the present-day local luminosity and mass functions of the two clusters; our data reveal a strong flattening of the mass function indicative of a significant preferential loss of low-mass stars in agreement with previous dynamical models for these two clusters. We made our NIRISS astro-photometric catalogs and stacked images publicly available to the community.2024A&A...690A.371Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/690/A371CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)J/A+A/594/A79 : NGC 6121 turnoff and subgiant stars abundances (Spite+, 2016)J/A+A/490/777 : Abundances of Population II stars in NGC 6397 (Lind+, 2008)J/A+A/503/545 : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)J/A+A/588/A148 : NGC 6397 stars MUSE spectra (Husser+, 2016)J/A+A/635/A161 : NGC6397 stars measured atmospheric parameters (Jain+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/690/A371https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/690/A371http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/690/A371https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/690/A371https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/690/A371http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/690/A371GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/690/A371/ngc6121 (NGC 6121 astro-photometric catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A371/ngc6121?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A371/ngc6121?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A371/ngc6121?GETtext/xml+votable180.050000true245.9476427703-26.61969363870.005555555555555556Cone search capability for table J/A+A/690/A371/ngc6397 (NGC 6397 astro-photometric catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A371/ngc6397?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A371/ngc6397?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A371/ngc6397?GETtext/xml+votable180.050000true265.3437986577-53.85867516790.005555555555555556Cone search capability for table J/A+A/690/A371/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A371/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A371/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A371/list?GETtext/xml+votable180.050000true245.95563-26.56850.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/690/A3716/42076 429551.192526870916184e-19 3.9057996558789745e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/690/A371?format=asciiOpticalInfrareddefaultJ/A+A/690/A371/ngc6121NGC 6121 astro-photometric catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRSRight Ascension (ICRS) at Ep=2023degpos.eq.ra;meta.mainindexedDE_ICRSDeclination (ICRS) at Ep=2023degpos.eq.dec;meta.mainindexedXposX master-frame position (40mas/pixel)pixpos.cartesian.xdoubleYposY master-frame position (40mas/pixel)pixpos.cartesian.ydoubleNameID number of the sourcemeta.id;meta.mainintF150WmagcCalibrated JWST/NIRISS F150W magnitudemagphot.flux.density;em.IR.HfloatF606Wmagc? Calibrated JWST/ACS/WFC F606W magnitudemagphot.mag;em.opt.RfloatnullableF814Wmagc? Calibrated JWST/ACS/WFC F814W magnitudemagphot.mag;em.opt.IfloatnullableFieldflag[1/2] Field flag (G1)meta.codeintMembership[0/1] Membership flag (1)meta.code.memberintsatF150W[0/9] F150W saturation flag (G2)meta.codeintF150WmagF150W instrumental magnitudemagphot.flux.density;em.IR.Hdoublee_F150Wmag? F150W magnitude rmsmagstat.errorfloatnullableqF150W? F150W quality-of-PSF-fit parametermeta.code.qualfloatnullableoF150W? F150W fractional flux due to neighbors within the fitting radius prior to neighbor subtractionphot.flux;arith.ratiodoublenullableqF606W? F606W quality-of-PSF-fit parametermeta.code.qualfloatnullablefF150W? Number of individual F150W exposures in which an object was foundmeta.numberintnullablegF150W? Number of individual F150W exposures used to measure an objectmeta.numberintnullablerxsF150W? F150W excess/deficiency of flux outside the fitting radius (RADXS)phot.flux;arith.ratiodoublenullableskyF150W? F150W sky in DNinstr.skyLevelfloatnullablermsskyF150W? F150W sky rms in DNinstr.det.noisefloatnullablesatF606W[0/9] F606W saturation flag (G2)meta.codeintF606Wmag? F606W instrumental magnitudemagphot.mag;em.opt.Rdoublenullablee_F606Wmag? F606W magnitude rmsmagstat.errorfloatnullableoF606W? F606W fractional flux due to neighbors within the fitting radius prior to neighbor subtractionphot.flux;arith.ratiofloatnullablefF606W? Number of individual F606W exposures in which an object was foundmeta.numberintnullablegF606W? Number of individual F606W exposures used to measure an objectmeta.numberintnullablerxsF606W? F606W excess/deficiency of flux outside the fitting radius (RADXS)phot.flux;arith.ratiodoublenullableskyF606W? F606W sky in electronsinstr.skyLevelfloatnullablermsskyF606W? F606W sky in electronsinstr.det.noisefloatnullablesatF814W[0/9] F814W saturation flag (G2)meta.codeintF814Wmag? F814W instrumental magnitudephot.mag;em.opt.Idoublenullablee_F814Wmag? F814W magnitude rmsstat.errorfloatnullableqF814W? F814W quality-of-PSF-fit parametermeta.code.qualfloatnullableoF814W? F814W fractional flux due to neighbors within the fitting radius prior to neighbor subtractionphot.flux;arith.ratiodoublenullablefF814W? Number of individual F814W exposures in which an object was foundmeta.numberintnullablegF814W? Number of individual F814W exposures used to measure an objectmeta.numberintnullablerxsF814W? F814W excess/deficiency of flux outside the fitting radius (RADXS)phot.flux;arith.ratiodoublenullableskyF814W? F814W sky in electronsinstr.skyLevelfloatnullablermsskyF814W? F814W sky in electronsinstr.det.noisefloatnullableJ/A+A/690/A371/ngc6397NGC 6397 astro-photometric catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRSRight Ascension (ICRS) at Ep=2023degpos.eq.ra;meta.mainindexedDE_ICRSDeclination (ICRS) at Ep=2023degpos.eq.dec;meta.mainindexedXposX master-frame position (40mas/pixel)pixpos.cartesian.xdoubleYposY master-frame position (40mas/pixel)pixpos.cartesian.ydoubleNameID number of the sourcemeta.id;meta.mainintF150WmagcCalibrated JWST/NIRISS F150W magnitudemagphot.flux.density;em.IR.HfloatF775WmagcCalibrated JWST/ACS/WFC F775W magnitudemagphot.mag;em.opt.IfloatMembership[0/1] Membership flag (G1)meta.code.memberintsatF150W[0/9] F150W saturation flag (G2)meta.codeintF150Wmag? F150W instrumental magnitudemagphot.flux.density;em.IR.Hdoublenullablee_F150Wmag? F150W magnitude rmsmagstat.errorfloatnullableqF150W? F150W quality-of-PSF-fit parametermeta.code.qualfloatnullableoF150W? F150W fractional flux due to neighbors within the fitting radius prior to neighbor subtractionphot.flux;arith.ratiodoublenullablefF150W? Number of individual F150W exposures in which an object was foundmeta.numberintnullablegF150W? Number of individual F150W exposures used to measure an objectmeta.numberintnullablerxsF150W? F150W excess/deficiency of flux outside the fitting radius (RADXS)phot.flux;arith.ratiodoublenullableskyF150W? F150W sky in DNinstr.skyLevelfloatnullablermsskyF150W? F150W sky rms in DNinstr.det.noisefloatnullablesatF775W[0/9] F775W saturation flag (G2)meta.codeintF775Wmag? F775W instrumental magnitudemagphot.mag;em.opt.Idoublenullablee_F775Wmag? F775W magnitude rmsmagstat.errorfloatnullableqF775W? F775W quality-of-PSF-fit parametermeta.code.qualfloatnullableoF775W? F775W fractional flux due to neighbors within the fitting radius prior to neighbor subtractionphot.flux;arith.ratiodoublenullablefF775W? Number of individual F775W exposures in which an object was foundmeta.numberintnullablegF775W? Number of individual F775W exposures used to measure an objectmeta.numberintnullablerxsF775W? F775W excess/deficiency of flux outside the fitting radius (RADXS)phot.flux;arith.ratiodoublenullableskyF775W? F775W sky in electronsinstr.skyLevelfloatnullablermsskyF775W? F775W sky rms in electronsinstr.det.noisefloatnullableJ/A+A/690/A371/listList of fits imagesNxNumber of pixels along X-axismeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainscaleScale of the imagearcsec/pixinstr.scalefloatNyNumber of pixels along Y-axismeta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar