Shootingfor(EvenMore!)OpenClusterChemicalAbundanceswith TheCannonAmyRay1,PeterM.FrinchaboyIII1,JohnDonor1,MatthewMelendez1

1DepartmentofPhysicsandAstronomy,TexasChristianUniversity,TCUBox298840FortWorth,Texas76129

Motivation

Stuff

Manyopenclusterchemicalabundancestudieshavesubstantialuncertaintiesfromstudytostudy.Afewreasonsareduetovaryingdataquality,thetypeofdata,whichcatalogwasusedfordistances,anddifferentdataanalysismethodsbetweenstudies.ThesedifferencestranslateintowidelyvaryingresultswhenattemptingtodetermineachemicalabundancegradientacrossthediskoftheMilkyWay.Inthisstudy,wedeterminedchemicalabundancesfora setof63openclustersbasedonauniformsystem.

TheCannon

• Stuff TheCannon(namedafterAnnieJumpCannonwhoisshowninFigure2),developedbyNessetal.(2015),offersauniquewaytofindstellarparameterswithouthavingtouseanymodels.Instead,ittakesasubsetofstars,calledareferenceset,withknownparametersor“labels”andcreatesamodel.Thismodelcanbeappliedtotherestofthesetofstarstoinferlabelsforthem.ThelabelsusedforthisstudyweretakenfromtheSloanDigitalSkySurvey(SDSS)IV/APOGEEDR16,whichobservedthesamestarsasourCTIO/Hydra-basedstudy.

Figure2: AnnieJumpCannonexaminingaphotographicplate.Credit:Harvard-SmithsonianCenterforAstrophysics

NewOpenClusterValues

Wefound[Fe/H]binaryresultsareshowninTable1.Wefoundaverage[Fe/H]valuesformorethan10openclustersthatdonothavepriormeasurementsfromspectroscopicdata.Afewofthepreliminaryresultsareshowninthetabletotheright.

ComparisontoOtherStudies

• Stuff

FutureWork

Wefo

WewillcombinetheclustersfromthisstudywithotheropenclustersfromthestudybyDonoretal.(2019)thatarealsobasedonAPOGEEdata.Thiswillallowustoexamineabundancetrendsinthegalacticdiskoveralargerradius.WealsohaveadditionalsetofopenclustersthatcanbeanalyzedwithTheCannonaftercompletingmembershipanalysis.

Inordertoconfirmourresults,wecompared[Fe/H]clustervaluestotwohighresolutionspectroscopicsurveys,onebySantosetal.(2009)andanotherbyReddyetal.(2013;2015).WealsocomparedthreeclusterswithDonoretal.(2019)whichisalsobasedonAPOGEEdata.Threeone-to-oneplotsofcomparisonsareshowninFigure4.

Figure4:(a)Comparisonto5openclustersincommonwithSantosetal.(2009).(b)Comparisonto5openclustersincommonwithReddyetal.(2013;2015).(c)Comparisonto3clustersincommonwithDonoretal.(2019).

AcknowledgementsTextgoeshereFundingforthisworkwasprovidedbytheNationalScienceFoundationundergrantno.AST-1715662.

OpenClusterSample

• Stuff

ReferencesTextgoeshere•SantosN.C.,etal.,2009,A&A,493,309

•Ness,M.,etal.,2015,ApJ,808,16•Reddy,A.B.S.,etal.,2013,MNRAS,431,3338

•Reddy,A.B.S.,etal.,2015,MNRAS,450,4301•Yong,D.,Carney,B.W.,&Friel,E.D.2012,AJ,144,95•Frinchaboy,P.M.,&Majewski,S.R.2008,AJ,136,118

DataforclustersusedinthisresearchweretakenfromastudybyFrinchaboy&Majewski (2008).ObservationsweretakenusingtheBlanco4-mHydraspectrographinChile.Frinchaboy&Majewski (2008)alsodidmembershipanalysisforeachclusterandFigure1isanexampleoftheresultsforM67.

Figure1:Color-magnitudediagramforNGC2682(M67).Membersusedinthisstudyareshownaslargeblackcircles. (a)

(c)

(b)