J/MNRAS/499/2327ivo://CDS.VizieR/J/MNRAS/499/2327CDSGoncalves G.Coelho P.Schiavon R.Usher C.2023-11-07T10:36:46Z2023-11-07T10:05:17ZCDS support team

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

cds-question@unistra.frglobular-star-clustersmilky-way-galaxymagellanic-cloudsgalaxiesmetallicitychemically-peculiar-starsradial-velocityvisible-astronomyspectroscopyThe pixel-to-pixel spectral fitting technique is often used in studies of stellar populations. It enables the user to infer several parameters from integrated light spectra such as ages and chemical abundances. In this paper, we examine the question of how the inferred parameters change with the choice of wavelength range used. We have employed two different libraries of integrated light spectra of globular clusters (GCs) from the literature and fitted them to stellar population models using the code STARLIGHT. We performed tests using different regions of the spectra to infer reddening, ages, [Fe/H], and [{alpha}/Fe]. Comparing our results to age values obtained from isochrone fitting and chemical abundances from high-resolution spectroscopy, we find that: (1) the inferred parameters change with the wavelength range used; (2) the method in general retrieves good reddening estimates, specially when a wider wavelength range is fitted; (3) the ideal spectral regions for determination of age, [Fe/H], and [{alpha}/Fe] are 4170-5540, 5280-7020, and 4828-5364{AA}, respectively; (4) the retrieved age values for old metal-poor objects can be several Gyr younger than those resulting from isochrone fitting. We conclude that, depending on the parameter of interest and the accuracy requirements, fitting the largest possible wavelength range may not necessarily be the best strategy.2020MNRAS.499.2327Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/499/2327CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/499/2327https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/499/2327http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/499/2327https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/499/2327https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/499/2327http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/499/2327GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/499/2327/table1 (Globular clusters present in the WAGGS data base and the reference values for ages and chemical abundances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/499/2327/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/499/2327/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/499/2327/table1?GETtext/xml+votable180.050000true6.024-72.0810.0055555555555555566/10336 12405 12425 12531 12943 19091 21017 24843 25873 27981 28067 28705 28741 28751 28769 28778 28882 28959 28973 29184 29187 29195 29216 29222 29267 29289 29294 29377 30769 31019 31115 31417 33093-33094 33096 33098 33112-33113 33120 33123-33124 33127 33137 33140 33304 33306 33317 33321 33323 33328 33330 33635 34242 35969 37294 38465 41304 41522 41852 42076 42278 42314 42700 42761 42841 42955 42990 43125 43227 44086 44220 47125 47620 47777 47825 47866 47868 47971 48035 48434 48698https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/499/2327?format=asciiOpticaldefaultJ/MNRAS/499/2327/table1Globular clusters present in the WAGGS data base and the reference values for ages and chemical abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGlobular cluster namemeta.id;meta.maincharGalaxyHost galaxy of the globular clustersrc.class.starGalaxycharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.main[Fe/H]Fe/H abundance ratiophys.abund.Fe;arith.ratiofloate_[Fe/H]? Error on [Fe/H]stat.error;phys.abund.Fefloatnullable[Mg/Fe]? Mg/Fe abundance ratiophys.abund;arith.ratiofloatnullablee_[Mg/Fe]? Error on [Mg/Fe]stat.error;phys.abundfloatnullableAge? Age of the globular clusterGyrtime.agefloatnullablee_Age? Error on AgeGyrstat.error;time.agefloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/MNRAS/499/2327/rvRadial velocities (calculated as described in Section 3.1) and average signal to noise for each spectrum of the WAGGS librarye_RV? Error on RVkm/sstat.errorfloatnullableSNRSignal to noise ratiostat.snrintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGlobular cluster namemeta.id;meta.maincharSpecName of the spectrum file (G1)meta.id;meta.filecharRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullableJ/MNRAS/499/2327/fitparamResulting parameters from the fits in R_W_ and their uncertainties from the perturbed spectra of the WAGGS libraryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGlobular cluster namemeta.id;meta.maincharSpecName of the spectrum file (G1)meta.id;meta.filecharlogtlightLogarithm of the fitted light-weighted agelog(yr)time.age;meta.modelledfloate_logtlightError on logtlightlog(yr)stat.errorfloatlogtmassLogarithm of the fitted mass-weighted agelog(yr)time.age;meta.modelledfloate_logtmassError on logtmasslog(yr)stat.errorfloat[Fe/H]lFe/H light-weighted abundance ratiophys.abund.Fe;arith.ratiofloate_[Fe/H]lError on [Fe/H]lstat.error;phys.abund.Fefloat[Fe/H]mFe/H mass-weighted abundance ratiophys.abund.Fe;arith.ratiofloate_[Fe/H]mError on [Fe/H]mstat.error;phys.abund.Zfloat[a/Fe]l{alpha}/Fe light-weighted abundance ratiophys.abundfloate_[a/Fe]lError on [a/Fe]lstat.error;phys.abundfloat[a/Fe]m{alpha}/Fe mass-weighted abundance ratiophys.abundfloate_[a/Fe]mError on [a/Fe]mstat.error;phys.abundfloat