1978AJ 83. . 2 4 4C only earlysubdwarfsandhorizontalbranchstarswith photon counterrorslessthan2%(3%intheultraviolet) completely separated(aswas thecasewithwidely were considered.Starswith<5<—20°rejected. m <10.0andlatesubdwarfsgiantswith9.0 spaced pairHD134439and HD134440).165195 or inferredmetaldeficiencies lessseverethan[Fe/H] known E(B—V)greaterthan 0.10.Starswithknown and HDE232078werethe onlyobservedstarswith Binaries wereexcludedunlessthecomponentscouldbe analyses werefavored overthosewithout.Choice ofsome goal. Ourstellarsamplewasconstrainedbythefollowing 244 Astron.J. 83(3),Mar.1978 requirements. eral practicalconsiderationsimposedlimitationsonthat widely representativeofPopulationIIspectraltypes, 073 andSpinradTaylor(1971)toawiderangeof = “0.5wereexcluded.Stars with publishedcomposition luminosity classes,anddegreesofmetalpoorness.Sev- metal-poor objects. selves. distributions andmetallicity,topicsofinterestinthem- of theseobjectsandtherelationshipsbetweenenergy hereafter 073).ItextendsthePopulationIresultsof present paperdealsonlywiththeenergydistributions population synthesesofmetal-poorstellarsystems.The scribed hereinwasperformedtoprovideadatabasefor v THE ASTRONOMICALJOURNALVOLUME83,NUMBER3MARCH1978 ABSOLUTE SPECTRALENERGYDISTRIBUTIONSAND[Fe/H]VALUESOFMETAL-POOR To facilitateindividualscantimesoflessthan4hwith © American Astronomical Society • Provided by the NASA Astrophysics Data System Our workcloselyparallelsthatofO’Connell(1973, The spectrophotometryofPopulationIIobjectsde- It wasourobjectivetoobservealargenumberofstars II. observationalprogramanddata applied to19objectswithpreviouslyundetermined[Fe/H]values. has beenused.Continuumandfeatureindicesarecomparedinternallywiththoseofthe M31 globularsarealsodescribed.ThewavelengthindexsequenceofO’Connell(1970,1973) temperature, luminosity,andmetalcontent,aregiven.Fivelocalglobularclustersfive Absolute spectralenergydistributionsfor65metal-poorstars,spanningawiderangein cal relationshipsbetween[Fe/H],color,andcertainfeatureindiceshavebeencalibrated as temperature,luminosity,andmetallicitycriteriaisextendedtometal-poorobjects.Empiri- Population IstellarsequenceofO’Connell.Hisdiscussiontheusefulnesstheseindices a) SelectionofStars I. introduction Department ofPhysicsandAstronomy,BrighamYoungUniversity,Provo,Utah84602 reduction California InstitituteofTechnology,Pasadena,91109 Received 31March1976;revised'9November1977 STARS ANDGLOBULARCLUSTERS Clark G.Christensen 0004-6256/78/8303-0244$00.90 ABSTRACT than =8.5theincompletenessofoursamplebecomes substantial. erate metaldeficiency,—0.5>[Fe/H]—1:0,citedin literature availablethrough1971.Atmagnitudesfainter brighter thanm=8.5ofindicatedmetaldeficiency globulars wereselectedasobjectsforinvestigation.[The our observingschedule. faint starswasalsoinfluencedbytheircompatibilitywith synthesis resultsaredescribedelsewhere(Christensen test andrefineoursynthesistechniquewhilefiveM31 population synthesis.Fivelocalclusterswerepickedto stellar data,theclusterswerechosenascandidatesfor other information,includingidentificationasametal- den Bergh’s(1969) linestrengthindexL spannedby was sufficientapparentluminosity. Theonlyaccessible, Table I,thebestcurrentvalues,aregreaterthan—0.5 on somestarshavebecomeavailablesincetheobserva- latitude. heavy lightcontaminationresulting fromitslowgalactic instrumentation wasM71.It wasrejectedbecauseof but unobserved,localcluster sufficientlybrightforour tions wereperformed,thevaluesgivenfor[Fe/H]in poor star,aregiveninthetable.Becauseadditionaldata Photometric dataareaveragedvaluesfromBlancoetal in afewcases. Wilson (1953)orEggen(1962,1964).Referencesfor (1968). Mostradialvelocitiesarefromthecatalogsof [Fe/H] <—1.0andabouttwo-thirdsofthosemod- 1972).] ObservedclustersaredescribedinTableII. v Table Igivespertinentinformationforobservedstars. Observed objectsincludevirtuallyallnorthernstars The strongestconstraintintheselectionofallclusters The fiveM31globularsrepresent thefullrangeofvan Although theyprovideavaluablesupplementtothe b) SelectionofGlobularClusters © 1978Am.Astron. Soc.244 1978AJ 83. . 2 4 4C HD 73394 HD 64090 HD 60778 HD 60552 HD 46703 HD 44007 HD 43039 245 HD 94028 HD 90362 HD 79452 HD 74721 HD 74462 HD 37160 HD 117880 HD 109995 HD 107328 HD 106223 HD 103095 HD 86986 HD 85504 HD 84937 HD 81192 HD 25329 HD 19445 HD 10700 HD 9774 HD 123598 HD 122563 HD 88609 HD 6833 HD 6755 HD 3546 HD 2665 geneous extensionof073’sresults. Theobservedspectral of X4800andAX=30Âin the red,toobtainahomo- tions, andthesamebandwidths, AX=20Âshortward this samewavelengthsequence, withslightmodifica- metal-poor stars.Itwastherefore advantageoustouse enough tobespectrophotometricallydetectedin regions aredescribedinTable III. dening, clusterslyingwellwithintheM31diskwere I starsincludesnearlyallofthevisualfeaturesstrong avoided. tances fromtheM31disk.Becauseoflikelihood light contaminationandsubstantialinterstellarred- M31 clusters.Theyhaveawiderangeofprojecteddis- 1973) Mt.WilsonenergydistributionsforPopulation # B—FforHD2665isabout0.74accordingtopresentobservations. The wavelengthlistemployedinO’Connell’s(1970, (11) Melbourne(1960). (10) Wallerstein(1962). (13) Cayrel(1968). (12) CayrelanddeStrobel(1966). (15) EggenandSandage(1959). (14) PagelandPowell(1966). (18) MacConnell(1970). (17) Bond(1970). (16) Bidelman(1965). (19) Eggen(1969).' Discussions of observed featuresarefoundin 073and *No publisheddatumwasfound.Valueisinferredfrompresentobservations. © American Astronomical Society • Provided by the NASA Astrophysics Data System (9) AllerandGreenstein(1960). (8) Stromand(1967). (7) SandageandEggen(1959). (6) Strom,Cohen,andStrom(1967). (5) Oke(1969b). (4) CayreldeStrobel(1966). (3) WallersteinandHelfer(1966). (2) HeiferandWallerstein(1968). (1) Koelbloed(1967). 4.08 8.06 4.33 8.51 8.00 6.74 4.37 6.01 8.29 6.44* 8.72 8.34 6.70 8.92 5.28 8.21 8.61 5.97 8.74 9.10 3.50 7.68 7,65 9.08 4.95 6.45 5.58 7.99 7.70 6.20 7.61 7.0 7.44 C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS c) SelectionofWavelengths 1 .02 1.18 1.00# -.04 1.03* 1 .52 1.62 1.16 .85 .95 .87 .47 .60 .10 .49* .50 .73 .96 .72 .87 .14 .41 .97 .48 .91* .94* .86 .03 .91 .04 .04 .30 .75 -.12 -.18 1 .86 -.24 -.08 1.15 U-B <5(U-B .14 .16 .37 .13 .53 .25 .22 .80 .64 .36 .21 .38 .17 .06 .06 .28 .20 .25 .09 .19 [km/sec] -0.21 -0.41 -0.40 -1 .81 -1.71 -0.31 -0.85 -1 .9 -1 .04 -0.75 -1.56 [Fe/H] Rad.Vel.References -168 -230 -139 -245 -320 -383 -132 -75 167 -96 -30 -31 -16 -84 -22 -45 -17 -98 99 97 39 20 62 58 13 -4 35 32 9 9.10.11.37 8,13,15 8.12.13.14.37 6.7.8.34.37 8,13,20 8,15,20,21 2,3 3.37 2.3.36.37 2,3 25,27,28 22 13.19 15 19 18 16,17 15 5 19 15.19 2.3.37 7.8.12.15.37 26 17 15.24.25.37 5 17 1 3.12.15.20.23.37 12.19.24.25.29.37 Table I.Programstars. References forTableI HDE 232078 HD 165908 HD 165195 HD 161817 HD 157089 HD 148349 HD 144579 HD 142574 +17° 4708 HD 186776 HD 185657 HD 182762 HD 175305 -15° 4515 HD 151937 HD 140283 HD 135722 HD 134440 HD 219617 HD 205539 HD 201626 HD 196610 HD 193901 HD 188510 HD 134439 HD 130952 HD 128167 HD 126778 HD 221170 HD 219615 HD 215373 HD 222107 wavelength, andX4970,which issensitivetotheTiO vations completebeyondX8050intheinfrared.Weused sensitivity toCNbandsandless sensitivitytoHgresults. shortward ofX3448wereobserved;norareourobser- X4954 band. We alsousedX4780rather than X4785todetectthe wavelength listandthatof073.Becausetherelative X4226, todetecttheneutral calciumfeatureatthat (X4860), butwedidobserveHa (X6564).Wealsoadded MgH X4845band.Unlike073, wedidnotobserveH7 indices. X3880 ratherthan073’sX3889wavelength.Agreater faintness ofourPopulationIIobjects,nowavelengths to facilitateformationofblanketing-free,reddening-free were chosentobe“clean”andnearfeaturewavelengths of strengthandsensitivitytotemperatureand/orlumi- nosity and/orchemicalcomposition.Continuumbands references therein.Featureswereselectedonthebasis (37) Moreletal.(1976)andreferencestherein. (36) GreensteinandKeenan(1958). (35) WallersteinandGreenstein(1964). (34) Pagel(1964). (33) Helfer,Wallerstein,andGreenstein(1959) (32) PrestonandBidelman(1956). (31) Kodiara(1964). (30) Eggen(1964). (29) WallersteinandHunziker(1964). (28) Slettebak,Bahner,andStock(1961). (27) Burbidgeand(1956). (26) Deutsch,Wilson,andKeenan(1969). (23) Wallersteineiö/.(1963). (25) Oke,Greenstein,andGunn(1966). (24) Kodaira,Greenstein,andOke(1969). (22) Eggen(1966). (21) Greenstein(1965). (20) Sandage(1964). There areafewminordifferencesbetweenour 6.96 8.83 6.4 6.5 8.48 7.17 6.95 9.2 6.58 6.67 5.44 9.46 6.30 6.3 8.64 7.35 5.24 9.12 4.46 8.14 5.15 5.10 9.44 4.94 8.18 7.69 8.17 5.08 7.26 3.50 3.88 3.69 1.59 1 .46* 1.60* 1.95 1.18 1.25 1.72 1.02 1.07 1.11 .99 .18 .36* .55 .99* .78 .66 .62* .73 .95 .47 .92 .97 .44 .59 .48 .86 .78 .52 2.03 -.13 -.12 2.15 -.10 -.02 1 .94 1.17 -.20 -.20 -.08 .68 .81 .16 .14 .21 .68 .68 .62 .57 .31 .19 .74 .67 [km/sec] 6(U-B) [Fe/H]Rad.Vel. .24 .00 -1.6 .14 -0.56 .22 .04 .21 .16 .20 -2.70 -0.78 -0.17 -0.51 -1.30 -0.46 -0.22 -0.54 -2.70 -1.40 -387 -363 -296 -152 -175 -201 -188 -162 -171 -120 -85 292 -42 -97 -43 100 -60 -61 -12 306 -14 -66 15 13 0 1 7 1 8.10.12.37 9,12,15,19,20 8 8.30 8.9.10.11.12.15.20.37 8,9,10,12,15 5 25 26 26 12.34 12,32,33 24.25.27.31.37 18 26 26 2.3.37 13 2.3.37 6.7.8.37 2,3 3.12.15.23 17 12.35 17.30 5 19.30 10.12.37 3.12.23 30 13 36.37 19 245 1978AJ 83. . 2 4 4C data wererejected.Integrationsterminatedand seeing scanswererepeatedseveraltimes.Inconsistent when seeingwasmoderatelypoor.Onnightsofpoor enough tosuppressspectraldegradationeffectseven confirm that the averagedenergydistributions have observed atleasttwice.Comparison ofseparatescans object toyield“restframe” energy distributions. wavelengths wereadjustedfor theradialvelocityofeach dards. Exceptforafewobjectsoflowdeclinationob- servations wererestrictedto secz<1.5.Theobserved program starsandlessthan3%forthebrighteststan- photon coincidencecorrectionswerenegligibleforthe dation wasminimizedbyholdingstarimagestowithin in thesecondorderof1.5-mtelescope,weresmall about 2arcsecoftheentranceaperturecenter. discarded wheneverimages“blewup.”Spectraldegra- scopes. The2.5-msystemwasoperatedinachopping ments. and requiredinterspersedskyobjectmeasure- ton-counting datasystemswereusedwithbothtele- mode; the1.5-msystemdidnotaccommodateachopper nights withtheMt.WilsonCassegrainscanner(Oke 246 1964) usingboththe1.5-and2.5-mtelescopes.Pho- Name (1)(2)(3)(4) M3 M92 M5 M15 M13 © American Astronomical Society • Provided by the NASA Astrophysics Data System Photon-count ratesweregenerallylowenoughthat The scalesatthescannerexitplane,e.g.,1.2Â/arcsec Except asnotedbyasterisks in TableVallstarswere (8) CrawfordandBarnes(1969). (7) Arp(1962). Stellar observationsweremadeon33photometric (6) SandageandWalker(1966). (5) vandenBergh(1967). (4) Arp(1965). (3) vandenBergh(1969). (2) KronandMayall(1960). (1) Morgan(1959). H 12 Name B282 H 140 H 55 MIV Morgan Sp.Line type index II II I I III C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS index Line (3) 15 11 0 8 d) ObservationofStars F7 FI F2 F6 F6 Disk edge Disk edge Halo Halo Halo -1 Projected location 4 0 6 3 -27° 41° 47° 78° 33° (arcmin) V 14.18 15.56 14.24 15.06 15.16 (3) Dq.9 12.3 12.9 10.7 (2) (4,5) V 9.3 9.4 Table H(a).Observedlocalglobularclusters. Table 11(b).ObservedM31globularclusters. 6.17 6.32 6.27 5.76 5.97 B-V 0.92 0.82 0.66 0.72 0.91 (3) References forTableII B-V 0.62 0.67 0.69 0.69 0.72 (5) U-B -0.01 (3) 0.47 0.16 0.12 0.49 of alargeraperture.Thischoice permittedroughly70 The strongcentral concentrationoftheseclusters helped scanner [accordingtoKronand Mayall(1960)bright- percent ofthelightfrommost clusterstoenterthe higher countratesandmorerepresentativelightsample lesser lightcontaminationofasmallerapertureandthe a compromisebetweenthebetterspectralresolutionand at thescannerexitplanewas2.66Â/arcmin.A0.79-mm moderate spectraldegradation.Thesecond-orderscale observe theintegratedlightfromclusterswithonly noise tolessthan30%ofthesignal atmostwavelengths. ness profiles]whilekeeping skyandbackgroundstar are describedinmoredetailtheirpaper. (8.1 arcmin)scannerentranceaperturewaschosenas Oke andSchild(1970)fortheircalibrationofaLyr porting pulse-countingdatasystemwereassembledby 45-cm Schmidttelescope.Thisequipmentandthesup- prime-focus scannertowhichitwasattached.Thein- using a10-cmNewtoniantelescopewithan//3.3focal struments weremountedonthesideofPalomar ratio matchingthe//3.3collimatorofHale5-m on photon-countstatistics. errors approach3%,consistentwithexpectationsbased errors oflessthan2%exceptshortwardX4000where U-B 0.02 0.06 0.04 0.13 0.09 The useofthe10-cmtelescopemadeitpossibleto Five localglobularclusterswereobservedon32nights (15) Bauma/.(1959). (14) Sturch(1966). (13) vandenBergh(1968). (12) deVaucouleursand(1964). (11) Sandage(1969). (10) McNamaraandLangford(1969). (5) (9) McClureandRacine(1969). e) ObservationsofGlobularClusters -0.19 -0.17 -0.43 -0.49 -0.40 Q (3) -0.43 -0.44 -0.44 -0.39 -0.41 (5) Q Rad. vel. (km/s) -241 -153 -118 -107 Rad. vel. (4) (km/s) -170 -348 -181 -247 -286 49 (3) 15.50 (4) 14.30 (4,15) 15.40 (6) 14.62 (6) 14.39 (7) m —M m —M 24.65 24.65 24.65 24.65 24.65 (13) 0.00 (8,9,10,11) 0.02 (10,11) 0.12(11) 0.02 (8,9,11) 0.02 (7,10) (3,9, 14) E-v B Eb-v 0.11 0.11 0.11 0.11 0.11 246 1978AJ 83. . 2 4 4C 247 degradation withthechosen 9.9-arcsecaperturecom- clusters filledthe8.1-arcmin aperture.Itistherefore similar tothoseofthelocalclusters thentheyfilledthe aperture. IftheM31globulars havebrightnessprofiles 9.9-arcsec aperturetoaboutthe samedegreeasthelocal parable tothatofthe10-cmsystem withthe8.1-arcmin plane oftheMCSP,2.5Â/arcsec,producedspectral segrain focusofthe5-mHaletelescope[seeOke(1969) for adescription].Thesecond-orderscaleattheexit likely thatspectral degradationeffectswere roughly multichannel spectrophotometer(MCSP)attheCas- violet andlessthan2%errorsatotherwavelengths. curacies inthefinalenergydistributionscomparableto those forthestellarsample,i.e.,3%errorsinultra- time foraccuraciescomparabletothoseofthestellar were performedintheeastwheneverpossibletomini- keep thelossofresolutionduetospectraldegradation accuracy. Nearlyallscanswereacquiredwithsecz< mize scatteredcitylight. Observations wererestrictedtomoonlessperiodsand modest. rather thantoobtainfewerscansofhigherstatistical and averagelargenumbersofshort,low-accuracyscans tinction onmanynightsmadeitadvantageoustoamass spectra. Systematicfluctuationsintheatmosphericex- 2/s intheultraviolet,necessitating20-30hofobserving 1.5. © American Astronomical Society • Provided by the NASA Astrophysics Data System The fiveM31globularclusterswereobservedwiththe A comparisonofscansforconsistencyimpliesac- A chopperwasusedtoremovethebackgroundsignal. Count ratesseldomexceeded20/sandwereaslow 4305 CHX4314,atomiclines 4270 Continuum 4200 CNX4216 4430 Interstellar 4400 Continuum 4226 CaIX4227 4101 Hô 4015 Continuum 4780 MgHX4845, 4500 Continuum 3860 CNX3883 3835 H 3815 Continuum,(FieI) 3798 H 3880 CNX3883,H 3784 Continuum 3620 Continuum 3570 Continuum 3448 Continuum A(Â) 3933 CaIIX3933 3910 Continuum 9 10 8 C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS TÍO X4762 AX =20Â Feature Table III.Programwavelengths. 10 800 10 400 4970 7400 7100 7050 6370 6180 6100 4780 9950 9190 8400 8190 8050 6564 5892 5820 5300 5175 8543 5050 8880 X(Â) 8800 were compared withinterspersedobservations ofthe Â. corrections typicallyleftresidualerrorsofIAX|^1 uum. 4%-5% inmostfeaturesto8%theultravioletcontin- roughness rangefrom2%intheredcontinuumand based onphoton-countstatisticsandobservedcontinuum was beingobservedatagivengratingtilt.Compromised vations toX5800,wellbeyondtheX4800limitof observe 15ofour17spectralfeaturesbetweenX3448and channels, itwasnecessarytouseninegratingtilts other second-orderobservations. the unavailabilityof30-Âbandpasses.MCSPinflexi- were 40ÂwidefortheMCSPobservationsbecauseof our programcontinuumbands.Mostfluxes cases observedcontinuumbandsdidnotcoincidewith comparable foralloftheobservedclusters. pletely forDopplershiftswhenmorethanonefeature applied toallMCSPchannelssimultaneously(except bility alsoforcedustoextendoursecond-orderobser- have thereforebeeninterpolated.First-orderbandpasses AXi =2AX2),itwasnotpossibletocompensatecom- X8050 (twowereomitted).Exceptinafewfortuitous The stellarandthelocalglobular clusterobservations Estimated errorsinthefinalenergydistributions Since identicalwavelengthincrementationmustbe Because ofthefixedwavelengthspacingMCSP f) SecondaryStandardStars TiO XX8860,8868 Continuum TiO XX7054,7088 TiO XX6148,6158 Nai Continuum Continuum (TiOX7054) Continuum Continuum Nal (He1X5876,TiOX5861) Continuum TiO 4954 Ca II Continuum Continuum Ha Continuum, (TiOX5814) Continuum Continuum Continuum Continuum CN XX9194,9198 Mg i(MgHX5211,TiOX5167) MgH X4845,TiOX4762 AX =30Â Feature 247 1978AJ 83. . 2 4 4C dards makesuchanapproach unsatisfactory.Thus,the calibrated wavelengthsinthe standardspectra, wavelengths exceptwherespectral featuresinthestan- energy distributionswereinterpolated attheappropriate of extinctioneffectsfromthe data. instrumental response functionwasinterpolated in standards (abouteverytwohours)facilitatedremoval detail byOke(1965).Afewcommentspeculiartoour situation follow. hundreths ofamagnitude.Frequentobservationsthe night atMt.Wilson).Typicalcolorvariationswereafew from nightto(andoccasionallywithinasingle bution consistentwithOke’s.) on thesameaLyrcalibration.(WealsoobservedHD calibration ofOkeandSchild(1970). energy distributions,providedbyOke(1970),werebased other standardsemployed.However,theircontinuum These twosubdwarfsarenecessarilyfainterthanthe secondary standardsHD19445andBD+17°4708. standard energydistributionswerebasedontheaLyr bright secondarystandardsofOke(1964).Theadopted 248 19445 asaprogramstarandobtainedanenergydistri- Since mostobservedwavelengths didnotcoincidewith The datareductionprocedurehasbeendescribedin © American Astronomical Society • Provided by the NASA Astrophysics Data System Residual extinctiontypicallyvariedby0.1or0.2mag Observations oftheM31clusterswerereferredto Name B/V V/B V/J V/l V/R MgH Ca II Ca n Mg I Na I Na I Ca I TiO TiO TiO TiO CN CH CN CN CN BL Name H H H H C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS 4226 4200 4101 4970 8880 6564 6180 4780 4305 9190 8190 7100 5892 3933 3880 3798 8543 5175 3860 3835 3835 Table IV(b).Continuumindices. 5300 5300 4270 5300 3570 Table IV(a).Lineindices. g) DataReduction 4500 4500 4270 4015 4015 4015 6370 6100 8800 8800 8050 7050 5820 5050 3910 8400 3815 3784 3784 3784 3815 5820 5820 4400 5820 3620 X 2 4226 4200 9190 6180 4970 4780 4305 4101 8880 8543 8190 7100 6564 5892 5175 3933 3880 3860 3835 3835 3798 10 400 8400 7050 4270 5300 ^3 9950 4270 9190 7400 6370 6100 4400 4270 4270 4015 8800 8400 7050 5300 5050 5050 3910 3910 3910 3860 3815 ^2 10 800 8800 4400 7400 5820 X 4 high-velocity objects lyingwelloutofthegalactic plane program stars.However,in mostcasesthestarsare terstellar extinctiondatawere notavailableforother the endofstellardatajustbeforeclusters. according totheextinctionlaw ofWhitford(1958).In- clearly intooneoftheprevioussubgroups,isenteredat but notperfectlywiththeindexV/R.TheCHstarHD plotted energydistributions.Thisorderingcorrelateswell observational data.Withineachgrouporsubgroup,stars 201626 (WallersteinandGreenstein1964),notfitting are listedinorderofdecreasingtemperatureasdeter- the b(U—B)vs[Fe/H]calibrationsofWallersteinand et al.1963)havehadtheirenergy distributionscorrected mined fromvisualinspectionofredportionsthe Carlson (1960)andWallerstein(1962),present - K)=0.07(Koelbloed1967); HD165195,E(B-V) = 0.25;andHD221170,E(B-V) =0.05(Wallerstein signments arebasedonpublishedabundanceanalyses, the approximatesubgroupboundary.Theas- all ofmoderatemetalpoorness),[Fe/H]=—1.0being groups arefurthersubdividedintoextreme-andmod- erate-metal-poorness subgroups(thefoursubgiantsare Stars aregroupedashorizontalbranchstars,giants, subgiants, andsubdwarfs.Thegiantsubdwarf grated clustermagnitudesareroughly0.4magbrighter.) of X5050lightcontainedintheaperture.Actualinte- malized toX5050.TheunnormalizedX5050magnitudes in magnitudeform.Theenergydistributionsarenor- (uncorrected forinterstellarabsorption)arealsogiven. distributions apparentlyresultsfromweakNaIDlines, (Cluster X5050magnitudesrepresentonlythatfraction feature. either intrinsicorinterstellar,and/ortheHeIX5875 a smallbutobviousdepressioninthestandardenergy Small correctionshavealsobeenappliedatX5892where been madeatX4305becauseofthepresenceaweak G bandand/orthevioletwingofH7instandards. corrections ofafewhundredthsmagnitudehave differences betweenourwavelengthlists,wegivein and X6564,thewavelengthsofH<5Ha.Calibration spectral regionsXX3650-4000andXX8400-9000where Table IVthewavelengthsofbandsweusedinindex dices (essentiallyfluxratiosexpressedinmagnitudes) formation. are formedisdetailedby073.Becauseofthesmall with 073’sPopulationIdistributionswehaveutilized his indexsystem.Theexactmannerinwhichthesein- Balmer andPaschenseriesconverge,aswellatX4101 Three starswithknowncolorexcesses,HD2665,E{B Table Vgivesenergydistributionsofprogramobjects To facilitatecomparisonsofourenergydistributions h) SpectralIndices III. RESULTS 248 1978AJ 83. . 2 4 4C 10800 -0.32 10400 -0.69 Lambda 4226 0.700.75 4101 0.750.84 4015 0.850.89 3933 1.921.96 4430 0.420.43 4400 0.530.54 4305 1.020.97 4270 0.710.76 4200 0.730.76 3880 1.691.66 3815 1.481.67 3798 1.471.52 8050 -0.68-0.69 4780 0.120.10 4500 0.280.29 3910 1.271.38 3860 1.641.77 3835 1.811.87 3784 1.331.44 3620 1.741.82 3570 1.812.09 3448 1.882.07 8543 -0.65 8190 -0.72 4970 0.020.03 Lambda 8880 -0.86 8400 -0.72 249 9190 -0.71 8800 -0.81 6564 -0.39-0.41 6100 -0.36-0.39 9950 -0.73 7100 -0.57-0.60 7050 -0.56-0.59 6370 -0.42-0.46 6180 -0.37-0.40 5820 -0.30-0.35 5300 -0.10-0.13 5175 0.02 5050 0.00 7400 -0.59-0.62 5892 -0.28-0.34 A5050 10400 10800 A5050 6.074.52 4101 4200 4015 3933 3910 3860 3835 4305 4270 4226 3880 3815 3798 3784 4500 4400 3620 3570 3448 4430 6100 4970 4780 6564 6370 6180 5892 5820 5050 7050 5300 5175 8400 8190 8050 7400 7100 8543 9950 9190 © American Astronomical Society - -0.14 -0.10 -0.09 -0.19 -0.22 -0.12 -0.13 -0.16 -0.17 -0.02 -0.04 -0.14 -0.14 79452 3546 0.54 0.44 0.15 0.27 0.95 0.07 0.54 0.97 0.99 0.21 0.17 0.04 0.00 "HD HD 0.44 0.30 0.26 0.24 0.07 0.43 0.69 Giants -ModeratelyMetalPoor C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS -0.03 -0.15 -0.08 Horizontal BranchStars -0.02 -0.04 -0.10 -0.08 -0.13 -0.11 -0.10 -0.12 -0.13 0.69 0.02 0.66 0.20 0.47 0.14 0.03 0.00 0.46 1.27 1 .27 1.27 0.58 0.16 0.05 0.23 0.20 0.35 0.62 0.20 0.47 0.38 0.35 21961 5215373135722 -0.09 -0.06 -0.10 -0.08 -0.08 -0.02 -0.11 -0.12 -0.14 -0.15 -0.17 -0.19 -0.14 -0.15 -0.41 -0.42-0.44 -0.40 -0.42-0.43 -0.32 -0.30-0.33 -0.35 -0.38-0.37 -0.72 -0.70-0.73 -0.62 -0.61-0.63 -0.61 -0.60-0.62 -0.42 -0.43-0.44 -0.46 -0.49 0.00 0.56 0.44 0.00 0.67 0.65 0.42 1.30 1.29 -0.61 -0.59-0.63 0.02 0.19 1 .27 0.11 0.04 0.15 0.45 0.39 0.33 0.28 0.20 0.18 0.16 0.14 0.27 0.42 0.39 0.54 0.28 2.14 2.522.25 2.23 2.352.32 2.06 2.432.15 3.86 5.30-3.55 0.80 0.88 0.97 1.051.04 1.97 2.192.17 2.20 2.582.39 1.88 2.241.93 1.78 2.091.90 1.87 2.102.01 0.11 0.100.12 0.34 0.36 0.52 0.55 0.61 0.630.65 0.79 0.820.85 0.89 1.060.95 0.89 1.030.93 1.50 1.671.61 2.13 2.522.26 1.62 1.931.70 0.00 0.03 1.09 1.051.15 0.05 0.070.06 11^80 -0.04 -0.09 -0.08 -0.03 -0.09 -0.13 -0.06 -0.09 -0.09 -0.11 0.00 0.64 0.48 0.00 0.56 0.06 0.04 0.27 0.68 1.33 0.15 0.12 0.02 0.00 0.21 1.26 1.19 9.02 0.16 0.58 0.20 0.17 0.28 0.33 0.26 0.66 -0.01 -0.05 -0.10 -0.01 -0.03 0.06 0.65 0.02 0.10 0.01 0.02 0.58 0.13 0.78 0.79 0.00 0.06 0.30 0.56 1.37 0.14 0.07 0.08 0.01 1.36 1.41 0.35 0.30 0.29 0.59 0.23 0.16 0.15 0.36 0.20 86986 -0.01 -0.07 -0.06 -0.05 -0.04 -0.05 -0.05 -0.04 -,0.01 -0.16 -0.33 -0.36 -0.38 -0.41 -0.46 -0.48 -0.48 -0.51 -0.41 -0.47 -0.41 -0.45 -0.66 0.14 -0.71 -0.79 -0.65 -0.67 0.60 0.02 0.16 0.76 0.34 0.75 0.55 -0.64 -0.69 0.00 0.40 1 .40 1 .42 7.94 0.09 0.04 0.04 0.00 1.36 HD 0.12 0.20 0.18 0.43 0.13 0.12 0.12 0.27 0.21 2.21 2.05 2.15 2.11 0.89 0.88 2.48 2.35 2.07 1.95 2.45 2.34 0.13 0.09 0.56 0.49 0.66 0.62 1.15 1.12 0.84 0.85 1.04 0.96 1.00 0.95 1.10 1.03 2.38 2.27 2.43 2.28 2.06 1.99 0.00 0.04 0.03 0.38 0.30 1.63 1.62 1.87 1.81 2.37 2.16 5.53 5.19 0.06 0.07 9774 130952 HD leVou -0.04 -0.02 -0.04 -0.03 -0.02 -0.01 -0.01 -0.01 -0.02 0.16 0.53 0.15 0.47 0.21 0.75 0.72 0.54 6.92 0.05 0.37 0.05 0.02 0.00 1.37 1 .41 1.48 0.12 0.08 0.07 0.07 0.07 0.00 Table V.Normalizedenergydistributions. 0.18 0.08 9.35 0.03 "HD RD— -0.01 -0.05 -0.01 -0.07 -0.07 -0.07 -0.05 -0.04 -0.09 -0.09 37160 182762 -0.18 -0.16 -0.00 0.05 -0.48 -0.45 -0.42 -0.40 -0.52 -0.49 -0.49 -0.46 -0.38 -0.35 -0.71 -0.67 -0.70 -0.68 -0.54 -0.52 -0.72 -0.69 0.15 0.50 0.31 0.32 0.60 0.38 0.71 0.46 0.71 0.57 0.05 0.07 0.09 0.20 0.14 0.16 0.16 1.11 1.16 -0.84 -0.75 0.01 0.00 0.09 1.08 0.02 0.15 2.06 2.12 4.34 5.35 2.25 2.44 2.05 2.49 2.25 2.60 1.76 2.09 2.34 2.47 0.10 0.12 0.63 0.68 0.92 1.02 1.02 1.11 1.53 1.74 1.95 2.29 1.88 2.22 2.43 2.32 0.30 0.35 0.50 0.54 0.82 0.89 0.87 0.94 0.87 1.05 0.06 0.09 0.00 1.15 1.19 1.62 1.89 -0.06 -0.04 -0.06 -0.08 -0.08 -0.06 -0.07 -0.03 0.48 0.56 0.25 0.80 0.68 0.49 0.92 0.65 0.85 0.73 0.19 0.18 1.29 0.08 0.24 0.15 1.17 1.22 0.16 0.02 0.00 0.01 0.02 0.11 0.13 -0.17 -0.07 -0.13 -0.02 -0.00 -0.18 -0.22 -0.22 -0.22 -0.09 -0.13 -0.14 Provided bythe NASA Astrophysics Data System ¿3039 107328 -0.17 -0.22 -0.48 -0.61 -0.47 -0.58 -0.36 -0.46 -0.43 -0.53 -0.70 -1.01 -1.00 -0.97 -0.93 -0.80 -0.85 -1.06 -0.70 -0.88 -0.70 -0.87 -0.52 -0.67 0.91 0.83 0.83 -0.90 -0.86 -0.73 -0.92 -0.54 -0.69 0.38 0.36 0.54 0.34 0.71 0.51 0.87 0.67 0.78 0.00 0.10 0.19 0.22 0.25 0.32 0.33 1.75 0.00 2.10 2.43 2.21 2.61 4.55 5.23 0.89 1.16 2.28 2.57 2.46 2.74 2.12 2.44 2.46 2.84 0.10 0.15 0.34 0.39 0.53 0.65 0.68 0.78 1.22 1.31 0.89 1.08 1.11 1.36 2.44 2.83 1.69 2.08 2.56 2.90 1.85 2.24 2.30 2.62 0.00 0.02 1.05 1.26 1.00 1.26 0.07 0.10 to— B ^Tür -0.25 -0.02 -0.45 -0.12 -0.31 -0.29 -0.22 -0.10 -0.59 -0.49 -0.45 -0.30 0.69 0.71 0.38 0.79 0.45 0.71 0.95 1.15 0.87 0.91 4515 0.23 0.41 1.15 9.98 0.00 0.05 0.12 0.31 0.31 0.36 0.40 1.49 1.46 Giants -ExtremelyMetalPoor -0.54 -0.35 -0.27 -0.12 -0.53 -0.31 -0.38 -0.34 -0.25 -0.60 -0.56 0.56 0.65 0.70 0.98 0.40 0.76 0.54 0.56 1 .07 0.98 1.22 1.12 1.36 0.04 0.27 0.36 1.52 1 .11 1.06 0.00 0.00 0.08 151937 -1.16 -1.89 -1.46 -2.25 -1.44 -2.19 -1.28 -1.98 -1.11 -1.79 -1.32 -2.05 -1.28 -2.03 -1.17 -1.83 -0.93 -0.99-1.27 -0.63 -0.64-0.82 -0.61 -0.63-0.98 -0.48 -0.51-0.59 -0.54 -0.83 -0.21 -0.40 -1.21 -1.90 -1.13 -1.23-1.82 -0.97 -1.05-1.61 -0.94 -0.96-1.44 -0.71 -0.74-1.06 -0.69 -0.73-1.14 2.99 2.803.45 0.00 0.05 0.06 0.21 0.160.31 0.49 0.450.53 0.77 0.680.83 0.84 0.770.99 1.24 1.101.88 0.09 0.020.23 1.34 1.29K47 1.11 1.011.47 1.46 1.361.97 2.20 2.022.82 2.61 2.323.13 2.72 2.343.20 2.44 2.153.08 1.28 1.111.69 1.36 1.211.77 2.72 2.393.17 2.79 2.473.34 2.92 2.653.32 6.76 2.33 2.052.91 2.51 2.363.08 2.67 2.512.92 HD -0.11 -0.26 -0.26 -0.59 -0.57 -0.56 -0.36 -0.35 -0.34 -0.65 -0.41 0.63 0.91 1 .05 0.93 1.08 1.04 1.33 0.00 0.00 0.26 0.33 0.38 0.74 0.49 0.53 0.50 0.62 1.32 1 .02 1.02 0.01 0.10 -0.36 -0.29 -0.10 -0.58 -0.57 -0.34 -0.40 -0.36 -0.27 -0.66 -0.60 -0.89 -0.70 -0.70 -0.68 -0.71 -0.95 -0.68 0.71 0.77 1.21 0.63 0.64 1.69 1.12 1.14 1 .28 1.27 0.00 0.04 0.30 0.41 0.47 0.83 0.64 1.19 1.22 0.00 0.13 “HD HDHÜ 90362 142574123598186776 6.03 5.897.617.01 -0.10 -0.30 -0.30 -0.72 -0.61 -0.58 -0.57 -0.39 -0.43 -0.36 -0.37 0.76 0.81 1 .12 1 .26 1 .59 0.00 0.03 0.31 0.43 0.56 0.95 0.67 0.69 0.70 1.70 1.14 1 .22 1.34 1.22 1.23 1.50 0.00 0.16 1 .57 -1.68 -1.17 -0.88 -1.02 -1.63 -1.33 -1.48 -1.12 -0.67 -0.87 -0.41 0.17 0.00 0.09 0.29 2.11 3.62 0.55 0.89 1.07 1.54 1.88 1.88 3.03 3.32 3.37 3.27 1.57 1.79 3.33 3.51 3.30 3.50 3.07 3.07 -0.36 -0.12 -0.74 -0.54 -0.49 -0.46 -0.37 -0.03 -0.89 -0.79 -0.75 -0.56 0.93 1.28 0.86 1.18 1.22 1.39 1.31 1.33 1.69 0.04 0.47 0.53 0.80 0.68 0.73 0.74 1.51 1.36 1.81 1.94 0.00 0.21 0.40 -2.48 -1.36 -1.84 -1.37 -1.20 -0.61 -1.13 -0.41 -0.82 -0.50 -2.27 0.57 0.59 0.87 0.96 0.20 0.00 0.30 3.34 2.77 2.98 1.34 1.41 1.84 1.57 2.01 2.95 2.98 3.16 3.03 2.84 3.05 1.71 3.12 2.63 -0.14 -0.92 -0.81 -0.79 -0.76 -0.58 -0.52 -0.40 -0.38 -0.04 -0.55 -0.51 0.41 0.49 0.72 0.67 0.89 0.97 1.20 1.40 1.76 0.00 0.02 0.19 0.52 0.75 0.78 1.33 1.27 1.38 1.43 1.42 1 .48 -2.61 -1.42 -1.42 -1.26 -0.57 -1.15 -0.43 -0.87 -0.56 -2.39 -1.97 0.00 0.34 0.57 2.00 3.43 2.99 0.22 0.56 0.86 0.90 1 .72 2.79 3.00 3.21 3.00 1.30 1.30 1.49 1.67 3.08 2.37 3.22 3.44 3.29 -0.41 -0.44 -0.16 -0.01 -0.81 -0.63 -0.55 -0.54 -0.98 -0.90 -0.84 -0.61 1.92 2.39 1 .86 2.06 2.08 0.00 0.04 0.19 0.42 0.61 0.66 0.88 0.97 1.17 1.71 1 .86 1.92 1.76 2.18 1.07 0.99 1.07 1.77 148349 -2.91 -2.67 -2.83 -2.79 -2.41 -2.37 -2.47 -2.42 -1.47 -1.76 -1.36 -2.09 -1.22 -0.76 -1.13 -0.57 -0.92 -0.45 0.50 0.18 0.00 0.22 0.72 1.04 1.15 1.71 2.10 2.07 3.64 3.39 3.19 1.60 1.88 2.38 3.12 3.29 3.32 3.47 3.31 3.40 3.56 2.95 5.78 HD ' -0.17 -1.02 -0.65 -0.58 -0.56 -0.44 -0.45 -0.05 -0.91 -0.87 -0.85 -0.64 2.16 0.80 0.88 2.05 0.58 0.99 0.86 1.00 1.11 2.01 1.48 1.59 1.96 0.00 0.07 0.45 0.62 1.51 1.73 1.61 1.63 1.59 0.18 5 1 9661O -0.57 -3.98 -3.56 -1.73 -2.61 -1 .81 -1 .44 -0.53 -1.26 -0.21 -0.89 0.94 0.32 0.00 0.71 0.61 0.81 0.97 1.04 0.84 0.75 1.30 0.66 0.73 2.50 2.20 2.15 1.76 1.97 2.06 2.04 2.91 6.40 2.50 2.83 1.91 -0.17 -0.84 -0.58 -0.4¿! -0.46 -0.05 -1.07 -1 .02 -0.86 -0.65 -0.57 -1.31 -1 .29 -1.08 -1.06 -0.51 -0.64 -1.26 -1.14 1.83 2.17 2.23 0.05 0.86 0.96 2.14 1.80 2.26 0.00 0.21 0.49 0.62 0.66 0.99 0.93 1.11 1 .24 -0.46 -1.93 -2.04 -1.49 -1.17 -0.97 -1.05 -1.60 -1.30 3.59 3.25 3.46 3.57 3.53 3.44 3.51 3.54 3.00 0.19 1.82 2.05 2.07 2.36 2.62 3.89 3.53 0.02 0.00 0.50 0.99 1.31 1.79 1 .37 249 1978AJ 83. . 2 4 4C 10800 10400 distributions arethereforelessreliablethanthoseofotherobjects. 250 objects.] servations indicateitisagiant. the colormagnitudediagram.[Strom etal.(1970)discusssuch probably oneofthosestarslyingwell abovethehorizontalbranchin large Balmerdiscontinuityimplies that itismorelikelyahorizontal branch star. 10800 10400 4400 4270 4226 4101 4015 8190 8050 4780 4500 4430 4305 4200 3910 3835 6564 5175 4970 3933 3880 3860 9950 9190 7100 7050 6370 6180 6100 5892 5820 5050 3815 7400 5300 3798 3784 3620 3570 3448 3784 3835 3798 3620 3570 3448 Lambda 4270 4226 4200 4101 4015 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G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Subdwarfs -ModeratelyMetalPoor -0.47 -0.49 -0.43 -0.34 -0.36 -0.16 -0.79 -0.65 -0.65 -0.45 -0.68 2.18 0.54 0.67 0.83 0.87 0.92 0.95 2.31 1.58 2.04 2.27 2.01 0.06 0.15 0.34 1.02 2.26 0.00 0.02 1.13 1.72 1.85 2.23 1.95 -0.18 -0.16 -0.18 -0.13 -0.05 -0.18 -0.02 -0.16 -0.14 -0.14 -0.10 0.74 0.89 1.09 1.15 0.31 0.35 0.34 0.59 0.40 0.97 0.81 0.66 0.99 0.78 1.11 0.14 0.19 0.51 0.64 0.01 0.05 0.23 0.00 0.02 -0.67 -0.50 -0.52 -0.40 -0.79 -0.70 -0.68 -0.47 -0.46 -0.35 -0.18 0.56 0.68 0.88 0.92 2.44 2.57 0.11 0.36 1.03 2.42 1.70 2.28 2.11 2.47 2.40 0.07 0.00 0.02 1.15 1.05 1.11 2.24 2.11 1.90 -0.17 -0.07 -0.20 -0.20 -0.13 -0.31 -0.33 -0.28 -0.09 -0.23 -0.30 -0.48 -0.45 -0.30 -0.33 -0.34 -0.29 -0.28 0.36 0.35 0.43 0.69 0.84 0.82 0.90 0.83 0.13 0.19 0.51 0.35 0.54 1.14 0.71 1.09 1.15 1.20 0.05 0.24 1.08 0.00 0.01 0.03 -0.59 -0.40 -0.47 -0.21 -0.96 -0.80 -0.79 -0.61 -0.54 -0.53 -0.84 0.82 0.95 2.01 2.09 0.11 0.00 0.07 0.29 0.51 0.61 0.87 0.90 1.05 2.18 1.62 2.26 2.05 2.29 0.02 1.08 1.89 1.76 2.24 1.97 157089 -0.36 -0.31 -0.31 -0.11 -0.23 -0.20 -0.20 -0.14 -0.17 -0.06 -0.29 W 0.54 0.96 0.94 0.64 0.42 0.42 0.59 1.38 0.82 0.86 0.98 0.92 1.21 1.36 0.44 1.23 1.28 0.20 0.28 0.33 7.00 0.04 0.06 0.00 0.05 84937 Subdwarfs -ExtremelyMetalPoor -0.07 -0.08 -0.02 -0.01 -0.14 -0.11 -0.12 -0.19 -0.22 -0.20 -0.19 -0.24 -0:22 -0.16 -0.29 -0.37 -0.27 8.33 0.96 0.43 0.58 0.47 0.65 0.92 1.02 HD 0.49 0.28 0.52 0.78 0.58 0.74 0.22 0.21 0.22 0.16 0.24 0.15 0.07 0.13 0.01 0.00 0.02 144579 HD -0.30 -0.12 -0.34 -0.33 -0.22 -0.58 -0.50 -0.50 -0.31 -0.39 -0.49 6.78 0.65 0.69 1.43 1.24 1.42 1.62 1.62 0.63 0.57 0.66 1.81 1.38 1.33 1.74 1.15 0.08 0.19 0.32 0.43 0.86 1.17 0.00 0.01 0.16 TTF- -0.01 -0.06 -0.14 -0.15 -0.06 -0.19 -0.19 -0.16 -0.25 -0.27 -0.29 -0.28 47C8 ' 9.52 0.68 0.96 0.98 0.61 0.53 0.82 0.64 0.77 0.47 0.47 1.13 0.33 0.72 0.23 0.26 0.23 0.15 0.26 0.15 0.02 0.13 0.00 0.03 HD— 10700 -0.32 -0.13 -0.30 -0.33 -0.34 -0.25 -0.54 -0.50 -0.50 -0.49 -0.39 0.72 3.68 0.63 0.61 0.68 1.34 1.34 1.86 1.29 1.24 1.11 1.50 1.57 1.66 0.90 0.64 1.73 1.13 0.00 0.01 0.08 0.25 0.36 0.49 0.10 -0.12 -0.05 -0.14 -0.06 -0.21 -0.18 -0.18 -0.25 -0.25 -0.30 -0.27 -0.43 -0.29 -0.30 -0.30 -0.26 -0.45 0.84 0.93 0.99 0.54 0.54 0.63 0.65 0.88 0.48 0.35 0.87 0.66 0.75 0.25 0.28 0.27 0.34 0.17 0.17 0.03 0.12 0.00 0.01 0.00 HD 201626 -0.03 -0.50 -0.27 -0.11 -0.92 -0.79 -0.59 -0.57 -0.56 -0.45 -0.84 -0.79 -0.63 8.35 2.10 2.14 0.92 2.15 2.44 2.27 1.98 1.75 1.80 1.10 1.19 1.65 1.86 0.06 0.37 0.56 0.87 1.51 1.05 1.10 1.90 0.00 ""HD HD 19445 219617 -0.14 -0.06 -0.17 -0.13 -0.19 -0.18 -0.30 -0.27 -0.28 -0.04 -0.32 8.06 0.93 0.65 0.86 1.00 0.56 0.81 0.53 0.68 0.64 0.74 0.48 0.36 0.73 0.26 0.29 0.28 0.32 0.21 0.19 0.03 0.15 0.04 0.00 0.00 Table V(continued) "M9T" ms -0.01 -0.19 -0.37 -0.30 -0.21 -0.06 -0.52 -0.48 -0.31 -0.57 -0.56 -0.37 6.76 Local GlobularClusters 0.89 1.45 0.66 0.89 0.91 0.81 0.87 1.27 1.38 0.71 0.54 0.82 0.68 0.40 0.46 0.46 0.33 0.43 -0.01 0.15 0.25 0.29 0.00 0.03 -0.14 -0.16 -0.06 -0.19 -0.19 -0.07 -0.21 -0.27 -0.27 -0.33 -0.32 8.29 0.96 0.74 0.63 0.93 0.72 0.82 0.70 1.01 1.04 0.61 0.53 0.42 0.93 0.34 0.29 0.34 0.25 0.41 0.24 0.03 0.06 0.18 0.00 Notes toTableV Provided bythe NASA Astrophysics Data System 140283 193901 -0.02 -0.27 -0.27 -0.09 -0.58 -0.40 -0.38 -0.36 -0.35 -0.57 -0.75 -0.60 6.75 0.97 1.60 0.72 0.99 0.89 0.99 1.37 1.45 0.49 0.52 0.76 0.60 0.91 0.91 0.78 0.33 0.53 0.52 0.15 0.34 0.35 0.00 0.04 -0.01 -0.18 -0.13 -0.18 -0.06 -0.36 -0.25 -0.22 -0.20 -0.39 -0.38 -0.34 0.96 0.93 7.27 8.73 0.66 0.90 RD hT) 0.62 0.74 0.54 0.75 0.49 0.35 0.51 0.66 0.26 0.30 0.30 0.63 0.34 r.20 0.22 0.19 0.08 0.00 0.01 the edgesofwhichsometimesliewithinobservedbands,making tribution cannotbedirectlycomparedwithothersinthesubgroup. observed Balmerdiscontinuities. exceeding 01 magnitudes, especiallyintheregion XX4780-5300,subjecttoerrors other extremesubdwarfsofcomparable temperature.Itmaybea horizontal branchstar. HD 222107assubgiantsaresomewhat uncertain,basedmostlyonthe -0.26 -0.28 -0.10 -0.01 -0.39 -0.36 -0.37 -0.54 -0.38 -0.72 -0.73 -0.55 -0.59 6.25 0.75 0.92 0.92 0.91 1.48 0.53 0.98 0.81 1.02 0.94 1.29 0.48 0.45 0.67 1.42 0.34 0.50 0.40 0.10 0.23 0.28 -0.17 -0.20 -0.09 0.00 0.02 -0.21 -0.10 -0.23 -0.21 -0.34 -0.30 -0.40 -0.33 6 5 7 0.79 1 .07 0.75 0.85 0.89 1.00 1.09 0.72 0.84 1,05 Ml 3 0.53 0.46 0.39 0.40 0.39 1.24 0.28 0.31 0.55 0.00 0.03 0.09 0.19 0.02 TheclassificationsofHD81192, HD 126778,185657,and ThespectrumofHD196610containsverystrongmolecularbands, BD+17°4708hasaslightlylarger Balmerdiscontinuitythan -0.10 -0.43 -0.28 -0.29 -0.60 -0.40 -0.38 -0.33 -0.60 -0.71 -0.64 -0.59 -0.82 -0.74 -0.78 -0.93 -0.58 -0.85 6.42 1.66 0.^9 0.54 0.75 0.99 1.56 0.38 0.59 0.54 0.65 0.82 0.89 1.19 1.09 1.00 1.45 0.15 0.25 0.34 1.01 1.12 0.02 0.00 0.06 -0.18 -0.19 -0.20 -0.08 -0.38 -0.36 -0.27 -0.25 -0.24 -0.39 -0.44 0.80 1.11 1.20 0.77 0.79 0.88 0.89 0.52 0.52 0.85 1.13 1.03 0.41 0.44 1.25 0.43 0.27 0.32 0.62 0.07 0.21 0.00 0.03 0.04 -0.05 -0.24 -0.17 -0.38 64090 134439 0.76 0.85 0.94 0.60 0.98 0.93 0.93 1.01 1.08 1.39 1.38 0.31 0.49 0.49 0.48 1.39 0.09 0.39 0.61 0.00 0.01 0.24 -0.18 -0.22 -0.07 -0.27 -0.23 -0.32 -0.29 -0.53 -0.43 -0.44 -0.55 -0.50 -0.43 -0.43 -0.57 -0.57 -0.52 -0.53 8.43 9.19 -0.11 -0.55 0.84 1.14 1.16 HD 0.90 0.82 0.96 0.87 1.02 0.82 1.08 0.53 0.54 1.29 0.46 0.48 0.46 0.31 0.66 0.19 0.26 0.04 0.00 0.03 0.07 15.47 15.45 -0.08 -0.03 -0.32 -0.30 -0.15 -0.39 -0.36 -0.36 -0.49 -0.54 -0.36 -0.78 -0.63 1.13 1.46 0.40 0.73 0.51 0.95 0.65 0.88 0.79 1.35 1.38 0.41 0.44 0.36 0.46 -0.32 -0.14 0.03 0.20 0.26 -0.35 -0.41 -0.35 -0.35 -0.28 0.00 -0.50 -0.52 -0.64 -0.55 1.57 1.51 1.13 1.38 1.27 1.23 0.69 0.73 1.16 1.79 1.34 0.66 0.72 0.64 1.83 1.27 0.33 0.44 0.89 0.12 0.24 0.10 0.00 0.02 -0.04 -0.28 -0.34 -0.11 -0.46 -0.34 -0.38 -0.80 -0.63 -0.64 -0.43 -0.72 1.22 1.40 0.92 1.29 1.51 0.74 0.55 1.03 0.51 0.49 0.52 1.27 1.18 -0.11 0.05 0.31 0.36 0.55 -0.26 -0.29 0.00 0.14 -0.43 -0.36 -0.36 -0.37 -0.57 -0.56 -0.70 -0.67 -0.59 -0.74 -0.64 -0.71 -0.76 -0.76 -0.73 -0.70 1.58 1.12 1.35 1.60 1.19 1.58 1.42 0.63 0.68 1.17 0.65 0.57 1.15 1.23 0.79 0.58 1.82 0.33 0.40 0.20 0.02 0.08 0.14 0.00 -0.29 -0.03 -0.45 -0.38 -0.32 -0.14 -0.63 -0.64 -0.45 -0.38 -0.71 -0.29 -0.35 -0.13 1.63 -0.44 -0.48 -0.43 -0.58 -0.41 0.84 0.72 1.32 1.54 1.64 -0.62 -0.61 0.58 0.58 0.66 1.08 1.24 -0.65 0.42 0.73 1.53 1.28 8.62 0.15 0.33 0.38 HD 0.00 1.78 1.97 1.55 1.78 1.46 1.44 1.66 1.81 1 .94 0.83 0.84 2.08 1.42 0.41 0.53 0.80 0.36 0.78 0.98 0.13 0.28 0.17 0.00 0.01 -0.16 -0.28 -0.48 -0.54 -0.51 -0.43 -0.71 -0.71 -0.53 -1.03 -0.86 -0.31 -0.34 -0.11 -0.41 -0.45 -0.40 -0.39 1.91 2.10 1.81 -0.62 -0.58 1.63 0.98 0.88 1.42 1.80 1 .44 -0.72 -0.65 0.46 0.89 0.76 0.85 0.81 2.13 0.06 0.37 0.46 0.08 0.00 0.00 1.58 1.73 1.67 1 .87 1.38 1.29 1.48 1.57 0.76 0.86 1.99 1.31 1.43 0.73 0.79 0.72 0.39 0.92 0.13 0.27 0.51 0.14 0.00 0.02 “Tío— 14.38 74462 -0.43 -0.30 -0.39 -0.53 -0.43 -0.13 -0.85 -0.70 -0.69 -0.56 -1.06 -0.01 -0.36 -0.38 -0.10 2.04 -0.51 1.61 1.68 2.08 B282 -0.54 -0.49 -0.45 0.99 0.96 2.09 1.43 1.71 -0.73 -0.73 0.74 0.80 0.82 1.85 1.54 -0.88 -0.76 0.55 0.88 0.39 8.82 0.00 0.04 0.08 0.53 0.12 2.02 1.86 1 .59 1.59 1.82 1 .69 2.00 1.58 1.60 1.63 1.83 0.87 0.87 0.84 0.94 1 .02 0.64 0.92 0.56 0.20 0.41 0.00 0.05 250 1978AJ 83. . 2 4 4C 251 of thesubdwarfs,allwhicharewithinadistance100 dening. energy distributionshavenot beencorrectedforred- which welaterinferE(B—V)^ 0.89.Globularcluster pc. Theonlyuncorrectedstarknowntobesubstantially and shouldsufferlittlereddening.Thisisexpeciallytrue reddened isthelow-latitude red giantHDE232078for dening.) V. (Thefeatureindicesarevirtually unaffectedbyred- © American Astronomical Society • Provided by the NASA Astrophysics Data System Table VIgivesspectralindices fortheobjectsofTable Feature Indices Continuum Indices Composite Index Feature Indices6755 Call 3933 Continuum Indices Call 8543 Composite Index MgH 4780 Cal 4226 TiO 4970 TiO 6180 Mg I5175 TiO 7100 Nal 5892 Nal 8190 TiO 8880 Call 3933.61 CN 3860 Call 8543 CN 3880 CN 4200 CH 4305 CN 9190 TiO 4970.01 MgH 4780-.05 Cal 4226-.01 TiO 6180.00 Mg I5175.06 Nal 5892.03 H 3798 TiO 7100.01 TiO 8880 Nal 8190 H 3835,BL3835 H 4101 H 6564 CN 3860-.03 CN 3880.05 U/B CN 4200-.02 CH 4305.25 V/R B/V V/I V/J CN 9190 khg H 3835,BL3835.16,.19 H 3798.02 H 4101.01 H 6564.12 khg .98 V/J V/R .35 U/B 1.06 V/I B/V .59 C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Horizontal BranchStars 35504 - -.13 -.02 -.36 -.26 1.10 .54, .37 .20 .00 .03 .03 Giants--Extremely MetalPoor .03 .01 .01 .00 HD HD 74721 -.12 -.02 -.21 -.27 1.38 .35 .42 .55, .42 .00 .72 .00 .03 .04 .00 .00 2665 17530544007 -.02 -.05 .00 .01 .36 -.03 -.01 -.02 .01 -.03 -.01 -.01 .00 HD 1.05 1.091-06 .10,-10 .07,.10.14,-15 .02 -.04-.03 .04 -.01.00 .10 .05 .47 .66.64 .01 -.01 .02 .03 .06 .04.05 .28 .25.31 .09 .11 .01 .03. .82 1.101.14 .39 .56 .65.68 HD -.10 -.02 -.01 -.20 1 .40 -.21 -.23 •57, .48 .34 .03 .45 .74 .00 .01 .06 .01 .02 .00 .33 .01 .02 .08 .23 .07 -.09 .00 .06 .14 .60 117880 -.17 -.01 -.03 -.16 1.35 -.20 .30 .48, .09 .66 .00 .02 .02 .00 .02 .38 .01 HD Spectral Indices 60778 -.13 -.03 122563 8860973394 -.12 1.38 -.22 .36 .55, .43 .73 .01 .04 TABLE VI .07 .08 .05 .01 .02 .00 .36 HD -.02 -.01.12 - •02_.04-. 1.28 1.301.44 •06 .07.08 .12,.13 .04,.05.02,.18 •04 .02-.06 •02 .03.00 •39 .34.82 •00 .03.01 •01 .00-.01 •10 .09.25 •01 .02.06 •03 .03.07 •00 .01 •01 .01.05 • 08.08.07 •00 ..02-.01 •52 .52.55 • 78.80.94 HD of eachourindicesasatemperature, luminosity,and metal-content indicatoramong PopulationIIstars. (Because ofinsufficientdata noinfraredindicesare differences between thecolorindexrelations ofstarsand curves representing073’sPopulation Idataforcom- considered.) Figures1-10,in whichwehaveincluded parison, illustratethediscussion. Wealsosummarizethe IV. DISCUSSIONANDAPPLICATIONOFRESULTS 86986 In theensuingdiscussionweevaluateusefulness -.16 -.09 -.01 -.12 1 .44 -.13 .52, .38 .31 .18 .04 .66 .04 .01 .00 .02 .29 .00 .03 .01 HD .42 1.32 161817 -.09 -.05 1.45 -.07 .45, .37 .26 .04 .25 .56 .00 .08 .00 .00 .00 .02 .02 .00 .28 .00 HD 4 221170 165195232078 106223 -.01 -.03.18 -.04 -.03 .08 -.01 .14 -.01 1.44 1.541.93 1 .02 .03 -.02-.07 .16,.18 .12,.10.04,.17 .07 .03-13 1.00 .91.96 .62 .61.81 .00 .06 .00 .01.06 .19 .24 .19.10 .01 .11 .02 .23 .29,.25 .35 .04 .26 .00 -.01.07 .08 .02 .01 .01 .18 .04 .05.14 .02 .01 .07 .06 .05 .02 .23 .03 HD HDE .93 .982.12 .13 . .56 .551.36 HD .06 -.01 -.05 205539 .09 .15 .86 -.08 -.02 1.11 .34,.29 .15 .15 .37 -.08 .01-.46 .34 .00 .10 .02 .00 .04 .03 .01 .24 HD .00 .03 .16 46703 -.03 1.58 .18,.22 .02 .04 .28 .24 .20 .03 .01 .07 .01 .02 .06 .02 HD .10 .01 .33 .14 4515 -.07 -.01 -15° 1.17 .26 .36,.33 .21 .07 .38 .00 .03 .07 .01 .01 .03 .04 .23 .01 .47 .29 251 1978AJ 83. . 2 4 4C yields neworcuriousconclusions. a fewindividualstarsforwhich applicationofourresults those ofclusters.Wethendescribethecalibrationand feature indicesforgiantsanddwarfs.Finally,wediscuss application ofempiricalrelationshipswhichyield[Fe/ H] asafunctionoftheVjRcolorindexandcertain 252 To betterreveal howspectralindicesvary with con- © American Astronomical Society • Provided by the NASA Astrophysics Data System Feature Indices Feature Indices Continuum Indices Composite Index Continuum Indices Composite Index Call 3933 Call 8543 Mgl 5175 TiO 4970 TiO 6180 MgH 4780 Cal 4226 Call 3933 TiO 8880 TiO 7100 Nal 5892 Nal 8190 Call 8543 CN 3880 CH 4305 CN 4200 CN 3860 MgH 4780 Cal 4226 TiO 4970 CN 9190 Mg I5175 TiO 6180 TiO 7100 Nal 5892 TiO 8880 Nal 8190 H 3835,BL3835 H 3798 H 4101 V/J V/I V/R CN 4200 CN 3880 CN 3860 B/V U/B H 6564 CH 4305 CN 9190 khg H 3835,BL3835 H 3798 H 4101 H 6564 V/I V/R B/V U/B V/J khg C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS a) SpectralIndices 51937 6833 -.05 -.02 -.02 .00 -.02 -.06 -.03 -.01 1.15 1.08 1.83 1.74 .07 .03 .07 .01 .02 -.03 .99 .95 .27 .20 .47 .36 .07,.51 .11,.43 .20 .13 .30 .35 .01 -.01 .09 .07 .01 .02 .08 .06 .93 .86 .06 .13 .57 .62 HD Giants--Moderately MetalPoor 79452 1 .33 -.04 -.02 -.05 -.07 ■.02 .34 .26,.50 .07 .75 .35 .01 .04 .07 .02 .31 .11 .01 .08 .56 .37 .68 .09 HD 1 .44 .01 .19 .03 .70 .36 •16,.46 .02 .03 .08 .01 .09 .01 .36 .74 90362 142574 -.02 -.02 .01 2.10 2.24 -.03 1.45 1.33 1.53 1.60 .86 .31 .29 .16,.47 .16,.46 .05 .08 .07 .03 .15 .17 .34 .25 .09 .10 .19 .16 .02 .20 .17 .03 .06 .19 .17 .28 .23 .44 .38 .89 .90 .11 HD 1 .41 .35 .02 .05 .02 .86 .37 .59 •22,.63 .05 .01 .05 .12 .02 .05 .36 .80 .09 215373 1.69 •.02 -.07 .83 .01 .09 .14 .03 .33 .29 .18 .07 .84 .75 .37 .23,.76 .03 Spectral Indices HD 123598 186776 TABLE VIcont. 1.59 1.60 1.90 2.38 -.07 -.06 1.40 1.47 .10 .11 .53 .61 .04 .07 .54 .61 .50 .52 .47 .53 .30 .31 .02 .77 .86 .16,.35 .17,.37 .06 .04 .23 .26 .06 .12 .35 .31 .17 HD 135722 temperature. Peak strengthsoccuraroundV/R =-0.25 guide derivedfromPopulation Istarsonly. ventional spectraltypeswehaveextractedtheapproxi- not regardthisrelationship as definitive.Itisarough mate relationshipbetweenV/Randspectraltypefrom Fig. 2of073.ItisgiveninTableVII.Thereadershould -.01 -.04 -.05 .09 .01 .06 .14 .36 .00 .05 .61 .30,.73 HD All fourBalmerindicesare sensitiveprimarilyto 1.62 9774 .38 .86 .05 .14 .01 .05 .36 .13 .01 5 .02 .01 .43 .71 .22,.71 .09 HD 148349 196610 2.05 1.89 1.93 1.23 2.45 -.06' -.01 -.05 -.19 1.81 1.50 .17 .18 .34 1.06 .03 .05 .40 .79 .40 .78 .42 .63 .13 .85 .18 .71 .07 .00 .29 .46 .02 -.20 .72 .96 .09 .10 .04 .02 .17 .24 .12,.31 .09,.35 HD 130952 /) BalmerSeriesIndices 1.53 .38 .83 .06 .15 .02 .06 .00 .05 .33 .00 .02 .30 .58 .17,-61 .01 HD 1.69 ■.05 -.04 -.03 .41 .84 .01 .06 .15 .38 .01 .01 .85 .32 .49 .29,.66 .03 81192 Subgiants -.01 -.03 -.01 -.04 -.08 1.44 1.521.65 .38 .40 .00 .08 .02 .05 .17 .35 .33 .85 .36 .36,.62 .06 HD 182762 1.63 .39 .88 .17 .00 .04 .36 .01 .87 .42 .69 .27,.77 .06 HD 126778 -.03 -.02 -.01 .00 .08 .00 .14 .34 .04 .87 .55 .01 .04 .01 .34 .19,.61 HD 1 .62 -.03 -.06 -.03 -.04 .56 .61 .41 .89 .08 .05 .00 .00 .07 .01 .08 .16 .39 .10 .90 .45 .71 .24,.77 .10 185657 -.03 -.06 .01 .07 .01 .06 .16 .33 .00 .11 .00 .66 .24,.75 .88 .43 .07 HD 107328 1.06 1 .84 •.03 -.04 .52 .07 .01 .33 .04 .01 .08 .21 .11 .95 .35 .60 .24,.73 .04 HD 252 1978AJ 83. . 2 4 4C 253 at somewhatlongerwavelengths, theH4101indexis izontal branchstars(Christensen 1972),despitethe uum lightinatypicalglobular clustercomesfromhor- graphically (Fig.1). parable color(either PopulationIorII).This property 0.1-0.2 magstrongerinclusters thaninstarsofcom- nearly completedominanceof redgiantsandsubgiants similar behaviorsoftheseindicesonlyH4101isshown as notedby073forPopulationIstars.Becauseofthe Since aboutone-fourthofthe XX4000-4200contin- © American Astronomical Society • Provided by the NASA Astrophysics Data System Feature Indices Continuum Indices Composite Index Feature Indices Composite Index Continuum Indices Call 3933 Call 8543 Call 3933 Cal 4226 TiO 4970 MgH 4780 Mg I5175 TiO 6180 Call 8543 TiO 8880 Nal 8190 TiO 7100 Nal 5892 TiO 4970 MgH 4780 CN 3880 CN 3860 TiO 6180 Mg I5175 Cal 4226 Nal 5892 CN 4200 CH 4305 TiO 7100 Nal 8190 TiO 8880 CN 9190 CN 3860 CN 3880 CH 4305 CN 4200 H 3798 H 3835,BL382 H 4101 H 6564 CN 9190 V/I B/V U/B V/R V/J H 3835,BL383 H 3798 khg H 4101 H 6564 khg V/J V/I V/R U/B B/V C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS 222107 103095 1.57 -.03 -.07 -.02 1.09 -.02 -.01 -.01 -.01 -.03 -.02 -.07 .19,.55 .01 .42 .70 .27 .01 .02 .33 .21 .08 .07 .01 .47 .87 .27,.45 .05 .00 HD .26 .79 .10 .02 .05 .20 .06 .08 .00 .03 .49 .58 .52 .37 HD 84937 Subdwarfs--Extremely MetalPoor 25329 .25,.22 .13 .05 .24 .12 .11 .00 .00 .02 .04 .00 .02 .02 .02 .00 .17 .02 .30 .06 .04 .22 .81 .27 1.23 .15 HD -.03 .14 .38 .14,.51 .12 .01 .00 .24 .00 .26 .05 .02 .81 .07 .07 .75 .37 HD 134440 4708 -.03 -.02 +17° .11 .23,.23 1.14 .01 .02 .17 .05 .03 -.02 -.05 -.06 -.03 .01 .02 .02 .16 .86 .17 .28 .18 .34,.57 .04 .79 .00 .25 .04 .10 .02 .05 .19 .71 .39 HD 74462 94028 -.04,.11 -.10 -.05 -.06 -.03 -.02 -.01 -.02 -.01 -.05 -.02 -.01 1.23 -.05 .04 .25,.23 .56 .37 .09 .01 .11 .01 .16 .11 .04 .04 .04 .86 .16 .01 .03 .03 .50 .01 .01 .26 .06 .28 .75 .27 HD .16 HD Spectral Indices TABLE VIcont. Subdwarfs--Moderately MetalPoor 128167 -.04 -.04 ■.01 .16 .34,.30 .01 • 20,.21 .33 .11 .11 .02 .15 .23 .02 .02 .08 .02 .22 .00 .04 .04 .01 .00 .06 .01 .07 .00 .02 .13 .95 .18 .02 .02 .03 .00 .03 .72 .30 HD .19 other Balmerindices. stronger instarsofnormal metal abundancethanin keting, theindexisafewhundredths ofamagnitude dwarfs. Ingiants,apparently asaresultoflineblan- do notseparatenoticeablyfrom thestarsinanyof galaxies andforegroundfieldstars.Theglobularclusters of globularclusterscouldbeusefulinphotometrically metal-poor objects. discriminating betweenthehaloclustersofexternal The H4101indexisnotaffected bymetalcontentin 219617 -.01 .13 .03 .28,.27 .01 .23 .22 .03 .01 .04 .01 .19 .90 .07 .32 -.02 .25,-26 .11 .02 .09 .36 .16 .03 .01 .13 .00 .03 .03 .16 .01 HD .76 .35 .18 165908 140283 -.04 -.02 -.01 -.01 -.06 •31 .07 .51 .11 .19 .14 .00 .00 .16 .01 .05 .07 .07 .00 .12 .35 .91 -.03 .16 .27 HD -.02 -.02 .10 .17,.15 .12 .15 .03 .17 .02 .09 .00 .02 .15 .00 .01 HD .69 .35 .24 157089 193901 -.03 •.03 -.05 .05 .33,.36 .10 .00 .63 .23 .14 .00 .04 .09 .01 .43 .97 .19 HD -.01 .07 .25,.29 .08 .00 .10 .58 .00 .18 .00 .00 .07 .04 .16 .01 HD .43 .75 .17 188510 -.03 -.07 -.01 -.01 -.01 1.13 .18 -36,.59 .14 .76 .29 .02 .11 .02 .22 .09 .28 .60 -.04 -.01 .05 .29,-34 .01 .05 .54 .03 .01 .24 .01 .08 .02 .12 .00 HD .81 .45 10700 64090 -.01 -.04 -.03 -.04 -.02 -.01 1.16 -.02 -.02 -.01 -.02 •55,.75 .22 .06 -.01 .15 .70 -.01 .17 .30 .12 .02 .07 .65 .27 .18,.25 HD .04 .54 .03 .00 .24 .00 .07 .13 .05 .00 .00 HD .12 .03 .77 .41 .47 .20 .28 134439 -.01 -.04 -.02 1.01 .02 .48,.65 .12 .05 .77 .04 .00 .29 .17 .05 .10 .02 HD .67 .30 253 1978AJ 83. . 2 4 4C dence onblanketing.InFig.2wenotethattheindexis deal ofscatterinthisindex. giants haveH3835indicesmorethan0.1magstronger as theBL3835indexwhichusessamecentral sensitive tometallicityalthoughnotnearlyso and mildPopulationIIsequenceswidelyexceedingthe nearly normalvalues,theseparationbetweenextreme than theirmoremetal-poorcounterparts.Thereis, We notethatthemildPopulationIIsubdwarfsand bandpass butdifferent,lessheavilyblanketed,sidebands. much moresensitivetoverylowmetalcontentthan tallic linesinlateFstars,theindexbecomesasensitive istence ofPopulationIIsupergiants. pergiants whichwefailtodetectbecauseofthenonex- probably becauseofdispersioninmetalcontent,agreat indicator ofmetalcontentbecauseitsstrongdepen- primarily H9.Withtheincreasingprominenceofme- luminosity. 073foundastrongseparationofB-Fsu- 254 The Balmerindicesshowinsignificantsensitivityto Because ofblanketing,theH3835indexissomewhat For starsbluerthanV/R=0.10thisindexmeasures © American Astronomical Society • Provided by the NASA Astrophysics Data System Sp. type Feature Indices Continuum Indices Composite Index 05 A0 A5 B5 B0 Call 3933 F5 F0 Call 8543 MgH 4780 Cal 4226 TiO 4970 TiO 6180 Nal 5892 Mg I5175 TiO 7100 Nal 8190 TiO 8880 CN 3860 CN 3880 CN 4200 CH 4305 CN 9190 H 3798 H 3835,BL3835 H 4101 H 6564 V/R B/V U/B V/I V/J khg C G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Table VII.Spectraltypt-V/Rrelation. -0.01 -0.19 -0.29 -0.38 -0.48 -0.55 V/R 0.08 201626 1.05 -.09 -.12 -.15 •.04 1.12 .71 .03,.50 .02 ii) BL3835 .37 .37 .51 .02 .07 .03 .02 .09 .42 HD Local GlobularClusters -.07 M92 .19 .17,.12 .02 .19 .04 .03 .22 .03 .05 .01 .02 .00 .02 .04 .40 .45 .03 Sp. type GO G5 K5 K0 MO M5 -.04 -.01 -.01 1.07 Ml 5 .15,.13 .06 .01 .21 .14 .01 .20 .09 .02 .02 .04 .00 .41 .59 0.16 0.70 0.37 0.90 0.27 V/R 1.7: 1.07 -.01 -.01 .15,.17 .00 .02 .28 .12 .05 .01 .18 .11 .04 .04 .06 .01 .05 .00 .51 .35 Spectral Indices TABLE VIcont. -.01 -.02 -.07 .14 .25,.26 .09 .33 .02 .15 .01 .03 .12 .02 .02 .07 .08 .14 .01 .29 .06 .60 .42 .56 .18 M5 with increasingluminosity. sequences. greatly, e.g.,ourmaximummeasuredindicesare0.75 behave similarly.However,theirsensitivitiesvary separation betweenPopulationIandmildII stars, theseindicesbecomesensitivetobothmetallicity for CN3860,0.463880,and0.184200. holds forPopulationII,sinceCNabsorptiondeepens K lineachievesthegreatest strength ofanyfeaturewe giants arewidelyseparatedfrombothextremely and luminosity.InFigs.34themildPopulationII somewhat weakensitsusefulness asametallicity consider. However,heavy saturation inthefeature of theM31globulars,anapparentindicationrelatively nearest —0.25,whereBalmerfeaturesarestrongest.We strength inthethreehorizontalbranchstarswithV/R by thevioletwingofH(X3890)asisevidentfromits in CN3860,thereisseparationwithmetalcontent. temperatures. Amongthecoolersubdwarfs,especially metal-poor giantsandfromsubdwarfsofcomparable With theappearanceofCNbandsinlateGandearlyK objects. There ismoderateseparation(<0.2 mag)be- discriminant, especiallyamong earlygiantswhereit achieves substantialstrength in eventhemostmetal-poor high metalcontent. note therelativelygreatstrengthofthisindexinsome 8 The indicesofCN3860,3880,and4200 A moderateluminosityseparationnotedby073also Figure 5illustratesthebehavior ofCAII3933.The Among hotterstarstheCN3880indexisinfluenced 1.03 -.02 -.04 .18 .10 .13,.14 .25 .14 .05 .17 .04 .03 .64 M3 1.11 -.05 -.07 -.01 .04 .33 .01 .26 .14 .06 .00 .00 .07 .00 .36 .52 -.01 -.03 ■.01 .43 .20 .00 .20 .09 .07 .02 .09 .07 .45 .54 .08 iv) Caii iii) CN 1.13 •.01 .54 .07 .19 .03 .04 .17 .14 .04 .04 .05 .02 .45 .68 1.31 -.01 -.05 -.12 -.07 .85 .07 .02 .14 .36 .22 .16 .16 .06 .85 -.01 -.11 .01 .78 .37 .02 .03 .11 .20 .10 .19 .02 .03 1.31 .51 .82 254 1978AJ 83. . 2 4 4C ^3" X 2 40 255 c.G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Fig. 1.TheHôindexversusthecontinuumV/R.symbolkeyisapplicabletosubsequentfigures.solidanddashedcurves © American Astronomical Society • Provided by the NASA Astrophysics Data System .00 .20 .60 .80 -.20 Fig. 2.Thelineblanketing indexBL3835versusVjR. NodataareavailablefortheM31 clusters. represent eye-fitcurvestothedwarfandgiantpopulationIdataof073. .00 .20 .40 .60 V/R V/o € LocalGlobularCluster O ExtremelyMetalPoorGiant 0 M31GlobularCluster Q Subgiant • ModeratelyMetalPoorGiant V ExtremeSubdwarf ▼ MildSubdwarf X HorizontalBranchStar 80 ! I 1.00 1.20 1.40 1978AJ 83. . 2 4 4C because oftheabsencelatesubdwarfs.Ashaslong 0.4) discussedby073isbarelyevidentforoursample dwarfs. been knownandisevidentinFig.5,theKlineespe- separate widely(0.3-0.4mag)inCaII3933,butthere sensitive tometallicity.Mildandextremesubdwarfs giants. AmonglategiantstheKindexissomewhatmore There issomewhatlessdifferencebetweenourmild tween earlygiantsofmildandextremePopulationII. is littleseparationbetweenmildsubdwarfsandnormal Population IIearlygiantsand073’sI o g.20 ro 00 oo 256 C.G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS A luminosityseparationamongcoolerstars(V/R> © American Astronomical Society • Provided by the NASA Astrophysics Data System .00 .40 Fig. 4.TheCN3880 indexversusV/R.Nodataare available forstarsofnormalmetal abundance. .40 .60 w V /R of theKstrengthsinindividualstars).Theclusters therefore arenotsoclearlyseparatedfromthestarsas of thetendencyforhorizontalbranchtobeleast clusters toscatterwidelyinthisindex(partlybecause prominent inthemostrichclusters,andpartlybecause that thedispersioninclustermetallicitiescauses even extremePopulationIIgiants.Wenote,however, metal-poor clustersthaninanystarofcomparablecolor, branch causestheKfeaturetobemuchweakerin cially sensitivetotemperatureamongA,F,andG stars. The strengthofvioletradiationfromthehorizontal 1.00 1.201.40 1978AJ 83. . 2 4 4C observed. Thisindexisslightlystrongerinextreme they areintheH4101index. subdwarfs thaninmildbecauseofsideband among earlierspectraltypes,wherebothsequenceswere tendency fortheindextobestrongerinmildPopu- tallicity intypesfrommid-F toatleastmid-Kexcept strength oftheGband,issensitive totemperaturein blanketing. lation IIgiantsthanintheextremePopulation comparable V/Rforcomparison.Thereisonlyaweak stellar typesFandGmoderately sensitivetome- objects exceptthesixcoolestmildPopulationIIgiants. Unfortunately, welackextremelymetal-poorgiantsof 257 virtually asstrongingiants ofnormalcomposition. among mildPopulationIIgiants, wheretheindexis No luminosityseparationis evident. The CaI4226indexisweak(<0.07)inalloursample CH 4305(Fig.6),whichmeasuresprimarilythe © American Astronomical Society • Provided by the NASA Astrophysics Data System In theglobular clusterstheindextendstobe roughly C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS v) Cai vi) CH Fig. 5.ThecalciumKlineindexversusV/R. with thatof073revealssensitivity tobothlow-and stars andisaffectedbyboth metallicity andluminosity high-level MgIconcentrations. in Gandlaterstars.Acomparison ofourdata(Fig.7) the btripletisstronglyaffected bytemperatureinG an abnormallycoolredgiantbranch. strength intheMgHorTiOindiceswouldhaveto giants. ThenonexistenceofveryredextremePopulation indices. Anyglobularclustershowingnon-negligible the six(fourforTiO4970)coolestmildPopulationII 0.1 magweakerthaninstarsofsimilarcolorandmetal II giantsconcealstheeffectofmetalcontentonthese stars toshortwavelengthluminosity. content. Again,aswiththeCaII3933index,cause 7100 registernoevidenceofspectralfeaturesexceptin is therelativelylargecontributionofhorizontalbranch The MgI5175indexwhichmeasures thestrengthof Among Gstars, wheresubdwarfshaveindices 0.1-0.2 The indicesMgH4780,TiO4970,6180,and vii) MgH,TiO viii) MgI 257 1978AJ 83. . 2 4 4C comparable color. /Mine strengthexceedingthatattainedingiantsof nent inthelong-wavelengthlightofaclustercanproduce M31 globularssuggeststhatastrongredgiantcompo- separation occursinstarsofnormalabundancetype separation ispresentinmetal-poorobjectsalthoughwide F andlater. spectral types.Onlyveryweakevidenceofluminosity ident, asissensitivitytometalcontentinthesesame tivity totemperatureinFandlaterspectraltypesisev- which measuresthestrengthofNaDlines.Sensi- temperature-restricted PopulationIIsample. A reversalinthesenseofluminosityseparationtype the indexisaparticularlyusefulluminositydiscriminant. M starsdetectedby073isnotrevealedourmore mag strongerthangiantsofcomparablemetalcontent, 258 © American Astronomical Society • Provided by the NASA Astrophysics Data System The greatstrengthofthisindexinthetworeddest Figure 8illustratesthebehaviorofNa15892index C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS ix) NaI sensitive tothestrengthofBalmerdiscontinuityand dependent onmetallicityformildPopulationIIobjects interstellar reddening. and starswithnormalcompositions.SinceE(khg)~ low concentrationsofheavyelements,butisonlyweakly —0.002 E(B—V),khgcanberegardedasinsensitiveto in latertypes.Itishighlysensitivetometalcontentfor spectral typesearlierthanKO.Itbecomessensitiveto luminosity atabouttypeK1andincreasesinsensitivity and theGband,ishighlysensitivetotemperaturein depends onthestrengthofCailKline,H Table VandisillustratedinFig.9.Thisindex,which gle-feature strengths,acompositeindexkhg=m\3933 + WA4305”2rax4iobhasbeenformedfromthedataof ô The behavioroftheU/Bcontinuumindex,whichis In additiontotheaboveindiceswhichmeasuresin- xi) U/B x) khg 258 1978AJ 83. . 2 4 4C 259 C.G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS © American Astronomical Society • Provided by the NASA Astrophysics Data System Fig. 8.ThesodiumDindexversusV/R. 1978AJ 83. . 2 4 4C Population II giants. is qualitativelysimilartothe dependenceinextreme similar color.Thedependence of£//£onVjRinclusters continuity smallerintheclusters thaninmoststarsof metal-poor giantsinglobular clustersmakesthedis- to differentialblanketing,isshowninFig.10.Wenote that amongmildPopulationIIgiantstheBalmerdis- continuity mayexceeditsstrengthinextremePopulation data of073showsthatthissensitivitypersistsforhigher metal contentalso. II giantsbymorethan0.5mag.Acomparisonwiththe 260 The presenceofrelatively earlysubdwarfsand © American Astronomical Society • Provided by the NASA Astrophysics Data System C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Fig. 10.ThecontinuumUjBindexversusV/R. V /R duces astandard deviationofa=0.036in Æ—F.A based onallsampleobjectswith publishedB—V,pro- squares-derived relation,B— V-0.864{B/V)+0.22, linear andsufficientlytight thatthesimpleleast- 0.1 magforsubdwarfsand0.2 magforgiants. and extremePopulationIIsequences amountstoabout sensitive totemperatureforallspectraltypeshotterthan early M.ThedifferentialblanketinginÆ/Fbetweenmild The correlationbetweenB/V and5—Fisnearly The behaviorofB/VissimilartoÆ—F.index xii) B/V 260 1978AJ 83. . 2 4 4C 261 ulation IIgiantsformostindices.Thebehaviorsofafew for thegalacticglobularclustersandclusterMIVof short-wavelength indicesareexceptional,however,be- M31 areindistinguishablefromthoseofextremePop- wavelengths intheclusters.Thus, theheavilyblanketed cause giantdominanceintheV/Rcolorindexandfea- ture indicesatlongerwavelengthsisgraduallyreplaced the Hline)indicesareafew hundredths ofamagnitude by horizontalbranchdominanceatprogressivelyshorter standard valuesforthosestars of thesameV/R.H4101,which ishardlyaffected,by stronger intheclustersthan in thePopulationIIgiants H 3798andCN3880(which containsthevioletwingof slightly better,eye-smoothedcurvewasusedtoestimate deviations are0.15fordwarfs abundance analyses.Standard in oursamplewithpublished same reason,CH 4305is^0.2magweaker andCaII 5 —FforsomeobjectsinTableI.Thereisnoappre- mean valuesof[Fe/H]versus blanketing, is^0.2magstronger intheclusters.For V/R-'màzx relationsbyfirstnotingthatsuch ciable departurefromtheaboverelationshipforanyof and 0.11forgiants. the designatedsubgroupsinoursampleofobjects. 8 Fig. 11.Inferredweighted We cansummarizethedifferenceinclusterandstellar © American Astronomical Society • Provided by the NASA Astrophysics Data System xiii) ComparisonofStellarandClusterIndices C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS LÜ X UJ -2.00 UJ < Z o X -2.50 -1.00 -1.50 -.50 .50- .00 r / L -2.50 -2.00-1.50-1.00-.50.00.50 / / V DWARFS o GIANTS / / rably coloredgiants.Thekhgindex,whichcombinesthe clusters thaninthegiantsbyover1.0mag. given V/RhasvaluesforH55andB282comparableto ulation Igiants,andtheU/Bcontinuumindex,whichat The twoexceptionsarethekhgindex,whichis^0.5 cluster relationsresemblethoseofPopulationIIgiants. globulars H55andB282resemblethoseofPopulation effects ofH4101,CH4305,andCaII3933,islessinthe values intermediatebetween MIVandthegalactic The aforementionedirregularitiesintheirindicescould chemical compositionssimilartoPopulationIobjects. giants. ItthereforeseemslikelythatH55andB282have those forPopulationIIgiantsratherthanI rather than1.0maglessintheclustersPop- these clusters,asclaimedby Christensen(1972). 3933 ^0.3magweakerintheclustersthancompa- be attributedtoanunusuallylargenumberofdwarfsin I giantsinthesamewaythatMIVandlocalglobular the other.Theobviousimplication isthattheyareof globular clustersatoneextreme andH55B282at in ourowngalaxy. intermediate metallicity,resembling mildPopulationII With twoexceptionstheL//?-indexrelationsofM31 The M31globularclustersH 12 andH140haveindex 70/7 / STANDARD [fE/h] / 7 / / / O / °/ / ° /o °/v / 70 «b/ / V / / / 261 1978AJ 83. . 2 4 4C 2 2 4305, MgI5175,andkhg.Aftercoefficientswerede- ciently strongandmetallicitydependenttoyielduseful the calibration.Comparisonsofstandardandpredicted used topredictavalueof[Fe/H]foreachstarin termined foreachindex,theresultingrelationshipwas data foreachofseveralindicesbyleast-squaresopti- relationships areBL3835,CN3860,CaII3933,CH where /representsindex,strength,havebeenfittothe mization ofthecoefficientsa-fThoseindicessuffi- lationships oftheform subdwarfs andforgiants.Forbothtypesofobjects,re- tween [Fe/H]andspectralindiceshavebeenderivedfor luminosity, independentsetsofempiricalrelationsbe- et al.(1976)orassumedtobezerowhenunavailable. of [Fe/H]forindividualstarsweretakenfromMorel deviation aforeachrelation.Aweightedmean[Fe/H] with datafrom073forpurposesofextendingourcali- or clusters.(Sinceclusterindicesdependonbothme- been attemptedforhorizontalbranchstars,subgiants, available [Fe/H]datamakesuchcalibrationspossible was thendeterminedformostoftheobjectsinourstellar the starsuponwhichmeantypesarebased.Values mean stellartypesof073areaveragesthevaluesfor brations tonormalcompositions.[Fe/H]valuesforthe tallicity andluminosityfunction,successfulcalibration for thesesubgroups.Forlackofdatanocalibrationshave cluster metallicity,isthemostpromisingindexforsuch of [Fe/H]-indexrelationshipsmightbedifficultto numbers ofgiantsandsubdwarfsinoursamplewith log(Fe/H)* —log(Fe/H)andthestrongerindices.The an attempttocalibraterelationsbetween[Fe/H]^ spectral indicesdiscussedintheprecedingsectionjustify to beproportionala~forthatindex.Suchachoice sample. Theweightassociatedwitheachindexwastaken [Fe/H] valueswerethenusedtodetermineastandard achieve. TheKlineindex,withitshighsensitivityto purposes.) [Fe/H] =a+6/c/d{V/R) 262 0 Giants Subdwarfs © American Astronomical Society • Provided by the NASA Astrophysics Data System Because ofthesensitivityspectralindicesto We havesupplementedourgiantandsubdwarfdata The strongcorrelationsbetweenmetalcontentand Object type b) Determinationsof[Fe/H]fromIndices C G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS CH 4305 Can 3933 khg CN 3860 khg CH 4305 Can 3933 CN 3860 BL 3835 Mg I5175 BL 3835 Mg I5175 Index 2 + e{V/R)fI{V/R), Table VIII.Empirical[Fe/H]-indexrelationships. -1.47 -1.43 -2.96 -3.59 0.18 6.05 2.93 3.83 3.40 5.56 5.94 1.16 a -2.83 -8.09 -2.57 -5.27 -1.58 29.87 12.17 10.48 12.70 11.52 6.67 2.95 -57.90 -13.76 -3.74 2 derived valuesof[Fe/H]fortheobjectsusedincali- also included.Figure11comparesstandardand O’Connell withassumedandderived[Fe/H]valuesare in calibration.Theutilizedmeanstellartypesof 5.84 all programdwarfsandgiantsinthetemperaturerange deviations indicatedinTableVIII.Extrapolatingmuch which calibrationswerebasedaregivenforobjectsused in TableIX.Adoptedstandardvaluesof[Fe/H]upon to whichtherelationsareapplicable.Resultsgiven tions describedinTableVIIIhavebeendeterminedfor results becauseofthegenerallylargecoefficients beyond thesespectraltypeswouldproduceunreliable ranges therelationshipsshouldproduceestimatesfor proximate spectraltyperangeG5-K5);withinthese 1.32 range 0.03-0.37(approximatespectraltype 1.61 (V/R) terms. F2-K0) andgiantsintheV/Rrange0.30-0.62(ap- c d subdwarfs andgiants,respectively.MgI5175,although the weakestofindicesconsidered,ismostaccu- dence ontemperatureovertheV/Rrangeconsidered; have beenderivedentirelyfromsubdwarfsintheV/R relationships relating[Fe/H],V/R,andindexstrengths rate predictorof[Fe/H]forbothdwarfsandgiants.The have beenassignedweightsofzerowhenappliedto range [Fe/H]>—1.Forthesereasonstwoindices because ofitsvirtuallycompletelosssensitivityinthe ond-order indextermintheempiricalrelationproduces CH 4305indexisapoorpredictorof[Fe/H]ingiants indices, probablybecauseofaverystrongindexdepen- to determine[Fe/H]insubdwarfsappearsbemuch c hasbeenassumedtobezero.UseoftheCN3860index of TableVIIIdeservecomment.Inseveralcasesasec- [Fe/H] withaccuraciescomparabletothestandard less reliablethanuseofanytheotheraforementioned no significantimprovementinthepredictedvaluesof of weightsminimizesthefinalerrorin[Fe/H]if each indexaregiveninTableVIII. normalized weightsfortherelationshipsderivedfrom are independent.Coefficients,standarddeviations,and errors inthedeterminationsof[Fe/H]fromeachindex [Fe/H]. Inallsuchcasesthecorrespondingcoefficient Coefficients Weighted meanvaluesof[Fe/H]basedontherela- A fewnotablepropertiesoftheempiricalrelationships -17.98 -19.19 -24.41 -26.40 -29.73 -15.47 -15.27 -4.07 -8.07 -5.23 2.62 3.89 -2.47 -0.42 -5.64 21.36 21.10 28.76 23.79 12.97 15.02 7.15 6.65 2.94 -12.63 -66.65 -14.59 -30.23 -33.00 -8.25 28.95 30.40 11.56 f 9.84 7.61 8.75 0.145 0.298 0.431 0.245 0.184 0.177 0.126 0.462 0.129 0.233 0.137 0.209 Weight 0.348 0.082 0.000 0.122 0.215 0.233 0.289 0.000 0.276 0.085 0.245 0.105 262 1978AJ 83. . 2 4 4C 263 correlated with[Fe/H]asthebestofourfeatureindices, bration. ThescatterinFig.11iscomparabletothe ciencies increasewithvelocity. However,HD134439, available propermotiondata. S,thetotalpeculiarve- the localstandardorrest, for thosesubdwarfswith with theu,v,andwcomponentsofmotion,referredto our indicesandb(U—B),althoughtheyexist,arenot we werenotsurprisedtofindthatcorrelationsbetween parameters. Sinceô(U—B)isnotnearlysotightly such astheclassicalindicatorô(U—B)andkinematic be correlatedwithothermetallicity-relatedparameters color, andcertainfeatureindices,atleastamongthe in theliteratureforindividualstarsusedcali- scatter inindependentdeterminationsof[Fe/H]found than mightbe expectedonthebasisoftheir motions. in thattheirmetaldeficiencies appeartobelesssevere locity, isalsogivenforeachstar. Generally,metaldefi- tight. subdwarfs andgiants,implythatourindicesshouldalso brations. Therefore,althoughtherelationsbetween HD 157089,and193901 aresomewhatanomalous dance analysisfortheircalibrations,theyshouldyield tional approaches. VIII aredependentupontraditionalmethodsofabun- [Fe/H], color,andfeaturestrengthsdescribedinTable [Fe/H] valueswithnearlytheaccuracyofmoretradi- b a AlthoughHD74462isidentifiedasadwarfinoursources,itsindicesindicateitprobablygiant. MeanspectraltypesfromO’Connell(1973). Table Xcomparesthemetallicityparameter[Fe/H] The strongcorrelationswhichexistbetween[Fe/H], © American Astronomical Society • Provided by the NASA Astrophysics Data System a a a a G8 V GO-5 V HD 10700 HD 165908 HD 157089 HD 144579 HD 60552 HD 25329 HD 188510 HD 140283 HD 94028 HD 84937 HD 64090 HD 19445 K0-1 V HD 134440 HD 128167 HD 103095 BD +17°4708 HD 219617 HD 193901 HD 134439 F5-8 V a Number/ Sp. type C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Subdwarfs/Dwarfs Standard -0.09 -1.40 -0.46 -0.56 -1.85 -0.54 -1.25 -1.81 -1.71 -0.31 0.01 0.08 0.02 Table IX.[Fe/H]valuesforgiantsanddwarfs. [Fe/H] Weighted mean -0.13 -1.62 -1.32 -0.62 -0.92 -0.62 -0.45 -0.39 -1.85 -1.71 -0.71 -0.48 -1.50 -1.29 -1.16 -1.25 -0.32 -1.49 -1.65 -0.37 -0.23 -0.09 0.22 value of—0.01±0.03ismostconsistentwiththe E{V/R) -0.76andE(BV) ^0.89,sinceE{B-V) uncertainty inthereddening correctionisabout0.1 color V/R^0.6producesfairagreementbetweenits low galacticlatitudesupportsthisconclusion. E{V/R) =0.30±0.05[E(B—V)0.350.05].Its of thestellartypesobservedbyusor073.Forthese weaknesses ofitsKlineandkhgindex.AnintrinsicV/R questionable spectroscopicparallaxes,plausiblekine- tremely metal-poorgiantsin thesample.However, may beslightlyredderintrinsically thantheotherex- Population IIstars.ThisvalueofV/Rwouldimply indices andthecolorindexrelationsderivedfromother reasons weconcludeBD—15°4515isreddenedby 0.29, itsBalmerindiceswouldbeinappropriateforany strengths ofthesefeatures.GivenitsobservedV/R= index tooredforthestrengthsofitsBalmerlinesor mag. 232078 iscorrectedwiththeWhitford(1958)law,a matic dataareunavailableforthegiants. Because ofunreliablysmalltrigonometricparallaxesand = 1.17(E{V/R).Thesevalues suggestthatHDE232078 The horizontalbranchstarBD—15°4515hasaV/R Although Eggen andSandage(1959) Eggen If thehighlyreddenedPopulationIIgiantHDE a a a b G5-8 III HD 2665 K3 III HD 182762 HD 175305 HD 79452 HD 44007 HD 43039 HD 6755 HD 3546 KO-2 III HD 221170 HD 219615 HD 215373 HD 165195 HD 151937 HD 135722 HD 130952 HD 122563 HD 107328 HD 88609 HD 37160 HD 9774 HD 6833 HD 74462 HD 73394 a Number/ Sp. type c) IndividualStars Standard Giants -0.22 -0.41 -1.04 -2.70 -0.48 -2.71 -0.85 -0.85 -0.75 -1.56 -0.21 -0.40 -0.06 -0.03 -2.70 -0.17 0.06 JTe/H] Weighted mean -0.20 -1.49 -2.65 -0.53 -0.23 -0.39 -2.69 -0.36 -2.72 -0.79 -2.32 -1.92 -1.45 -0.21 -0.49 -0.22 -0.99 -1.06 -0.75 -1.49 -0.15 -2.62 -0.27 -0.04 0.07 0.05 263 1978AJ 83. . 2 4 4C _l -1 with theextremesubdwarfsinTablesVandVI.Its within 0.10of—0.71.This compares with[Fe/H]^ s (Wilson1953).However,thefivelineindicesused 292-km sradialvelocity(Eggen1964)anditsCN to determine[Fe/H]allsuggest its[Fe/H]valuetobe its obviousassociationwithextremesubdwarfHD 3860, andU/Bindicessupportthisclassification,asdoes especially BL3835,Can3933,CH4305,andMgI indices aremorecompatiblewithagiantclassification, is treatedassuchinTablesVandVIFigs.1-10.Its the [Fe/H]-index relationswerecalibrated. However, (1964) haveclassifiedHD74462asasubdwarfandit result fromtherelativelyred colorofHD134440,V/R between theindicated[Fe/H] valuesforthispairmight 5175. WehavetreateditasagiantinTableIX.A poorness. 134440, only5arcminawaywithradialvelocity306km -1.71 foritscompanionHD 134440.Thedifference that thisstarlieswellabovethehorizontalbranch(see = 0.39,whichis0.02magbeyond therangeforwhich combined toyieldthefinalenergydistribution. complicating irregularityisitsunusuallylowfluxdensity are giants,theirindicatedvaluesof[Fe/H]—0.38, difficult whenawiderangeinmetalcontentispossible. Fig. 10).TheweaknessofitsKlineconfirmsmetal nosity classesonthebasisofindicesbecomesespecially especially HD185657.Distinguishingbetweenlumi- V andVIcouldconceivablybereclassifiedasagiant, however, itappearedinbothofthescanswhichwere in theX3815band.SinceisasidebandforH It ispossibletheX3815depressionanobservingerror; —0.43, —0.28,and—0.92,respectively. If HD81992,126778,185657,and222107 3798, H3835,andCN3880indices,allareanomalous. 264 a Statedvalueisweightedmeanimpliedbyfeatureindices.OthervaluesincolumnarefromreferencesgivenTableI. We havelistedthehigh-velocitysubdwarfHD134439 © American Astronomical Society • Provided by the NASA Astrophysics Data System The sizeoftheBalmerjumpinHD46703confirms Any ofthefourstarsclassifiedassubgiantsintables C. G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS + 17°4708 HD/BD 219617 128167 103095 134440 134439 193901 157089 144579 140283 165908 94028 64090 84937 25329 10700 19445 Table X.Comparisonof[Fe/H]andkinematicdataforsubdwarfs. a a a a a a a a [Fe/H] -0.31 — 1.29 — 1.25 -1.81 -1.71 —0.39 —0.71 -0.54 -1.25 — 1.66 — 1.62 -1.40 —0.62 -0.46 -0.56 -1.85 — 1.71 HD 74462,134439,10700,and215373 components. Allbutthementionedspectralindicesof our dataarenotadequatefortheresolutionofoverall grateful toJ.B.Okeformaking availableHale5-m- individual starsfallwithinexpectedlimits. abundance parameter[Fe/H]intoseparatechemical velocity confirmthephysicalassociationofHD134439 tions. values forHD134440varyingonlyfrom—1.54to1.83. telescope timefortheM31 globular clusterobserva- for sharingdatapriortopublication. Iamespecially metal contentisaseriousoversimplification.However, may indicatethatasingle-parameterrepresentationof color. SinceHD10700wasscannedfourtimesand although itsotherindicesconfirmmetalpoorness.HD structures. Furtherstudyofthisinterestingpairis possibility theirphysicalassociationhasinfluenced and HD134440.Sincethetwostarsareseparatedbyat fellowship. have causedtheseapparentpecularities. indices (aboutthestrengthexpectedforPopulationI) planned. least severalthousandastronomicalunits,thereislittle Common valuesofparallax,propermotion,andradial produce alargeerrorin[Fe/H],especiallysincethefive 215373 twice,itseemsunlikelythatobservingerrors 215373 hasanunusuallystrongCN4200indexforits indices usedindetermining[Fe/H]individuallyimply it seemsunlikelythatsuchasmallextrapolationcould The above-mentionedirregularitiesinthespectraof The authorexpresseshisthanks toR.W.O’Connell Part oftheworkwassupported byanNSFpredoctoral HD 10700hasrelativelystrongH3835andBL -205 -300 -289 -274 -129 -259 -172 -28 -12 186 143 149 194 -6 24 24 28 Peculiar velocity(km/s) -254 -149 -172 -132 -433 -430 -137 -113 -104 -169 -179 -124 -44 -35 41 28 11 -11 -81 -85 -15 -28 -35 -30 -12 -5 -9 80 20 30 16 17 19 2 224 229 325 255 528 519 319 235 306 154 117 166 184 20 52 53 30 264 1978AJ 83. . 2 4 4C 265 C.G.CHRISTENSEN:ABSOLUTESPECTRALENERGYDISTRIBUTIONS Bidelman, W.P.(1965).VistasAstron.editedbyA.Beer(Pergamon, Arp, H.(1965).GalacticStructure,editedbyA.BlaauwandM. 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