1985ApJS. . .57. .6 65B morphology ofgalaxiesinnearby clustersandfoundevidence galaxies indistantclusters with colorspredictedfromthe evolution ofclustergalaxies(ButcherandOemler1978æ,Z?). formation andgalaxystructuregenerallyfoundinfield gal- in particular,ofclustergalaxies,mayoccupymorethan the possibility thattheformsandstellarcontentofgalaxies, and, is aquahtativeandinexactprocedure.Furthermore,theex- for strongrecentevolution of galaxypopulations.However, Our initialstudiescompared thedirectlyobservedcolorsof axies. Finally,problemsofresolutionlimitthemorphological exhibit thegoodcorrelationbetweenpresentrateof star istence ofanemicspirals(vandenBergh1976)raises the typing ofgalaxiestofairlynearbyobjects. essentially one-dimensionalparameterspacerepresented by ral approach. existing studiesofpopulationvariationshavebeenbasedon lations exist,particularlybetweenclustersandthe“field,” from inspectionofphotographicplates,thisisthemostnatu- galaxy morphology,andparticularlyongalaxies’locations the Hubblesequence.Specifically,clustergalaxiesmay not and sincethemorphologicaltypeofagalaxyiseasilyobtained sequence isthesinglemostimportantpropertyofgalaxies, along theHubblesequence.Sincelocation about theprocessesofgalaxyformationandevolution.Most that thesevariationsmustcontainsignificantinformation The AstrophysicalJournalSupplementSeries,57:665-691,1985April & 1985.TheAmericanAstronomicalSociety.Allrightsreserved.PrintedinU.S.A. For someyearswehavebeenengagedinastudyofthe It does,however,haveitslimitations.Thetypingofgalaxies It haslongbeenrecognizedthatvariationsingalaxypopu- -1 dispersion thanwouldhavebeenpredictedfromtheirmorphologicaltypes. decreases withmagnitude.However,thecolorsofspiralgalaxiesarenotentirelyasexpected,havingasmaller center andbrighterthanJ=11.5.Theaccuracyofthephotometryvarieswithcluster,butmostmagnitudesare morphological typesarepresentedforgalaxiesinthecoresof10nearbyclustersgalaxies.Intypicalcluster, fields towardtheGalacticpolarcaps. the densityoffieldgalaxieshasalsobeenmadeusingexistingdata,extendedwithnewmeasurementsintwo accurate to0.10mag,andtypicalerrorsinthecolorsareofsameorder. the sampleincludesallgalaxieswithinaradiusof1.5Mpc(assuming7/=50kms)cluster Subject headings:gaüdúáes:clustering—galaxies:evolutionphotometrystructure 0 As expected,thecolorsofellipticalandSOgalaxiesshowanarrowdispersionaboutmeancolorwhich In ordertocorrectforforegroundandbackgroundcontaminationoftheclustersamples,adetermination Colors andmagnitudes,obtainedfromPalomar48inch(1.2m)SchmidtplatesintheJFbands, © American Astronomical Society • Provided by theNASA Astrophysics Data System THE EVOLUTIONOFGALAXIESINCLUSTERS.IV.PHOTOMETRY I. INTRODUCTION 10 LOW-REDSHIFTCLUSTERS Received 1984July3;acceptedOctober9 Kapteyn AstronomicalInstitute Augustus Oemler,Jr. Yale UniversityObservatory Harvey R.Butcher ABSTRACT AND 665 we areawarethoseoftheComaClusterbyGodwin, photographic andphotoelectriccolormeasurementsexistfor we presentphotometry,positions,andmorphologicaltypes of we hadsuitableplatematerial, toprovidearangeinrichness, galaxies in10nearbyclusters,aswellanestimateof the obtain theneededdataourselves,forourownpurposesand in Metcalfe, andPeach(1982).Wehave,therefore,setabout to only sufficientlycompleteandaccurateobservationsofwhich subsets ofthepopulationsafewnearbyclusters,but val 0.0redshift procedure wouldbetolookforvariationsusingauniformset Sarazin, Rood,andStruble 1982), andgalacticlatitudesare original observationsoftwodistantclusters,weobtained of photometryclustersateveryredshift.Tosupplementour this isnotaverysatisfactoryapproach.Inadditiontothe The 10clusterswereselected,fromamongthoseforwhich Surprisingly, fewsuchdataexistintheliterature.Some II. OBSERVATIONS 1985ApJS. . .57. .6 65B _1- photometry ofSearle,Wilkinson,andBagnuolo(1980)with photoelectric equivalentsareillustratedinFigure1ofOemler behind aRG610filter,definingbandwhichwecallF.The which wecallJ.Redplatesareon103a-For098emulsion Abell 262,1367,andtheHerculesClusterareirregular presented inthefirstthreecolumnsofTable1.Theclusters column ofTable1. clusters, withlargepopulationsofspiralgalaxies;theother photometry ineachclusterarepresentedthefourthand plete tothemagnitudecutoff,whichvariesfromcluster location ofthedominantgalaxyinthoseclusterspossessing lated assuming770=50kmsMpcand0.1.This individual clusters.Towithintheerrors,galaxiesappearto illustrated inFigure1.Thesmoothcurverepresentstheob- 0.0. Exceptforadifferenceinzeropoint,thephotoelectricJ ment that,forastarwithB-V=0.0,J-F=0.0andJ-V response functionsofthesephotographicbandsandtheir Palomar 48inch(1.2m)Schmidttelescope.Blueplatesareon cores. Abriefdescriptionofeachclusterisgiveninthelast seven arecompact,regularclusterswithfewspiralsintheir clusters. Withintheselimits,thephotometryshouldbecom- one orhasbeendeterminedbystripcountsinirregular within adistancefromtheclustercenterof1.5Mpc,calcu- den Bergh(1981).ThepointscomparetheB-VandJ-F determined bycomparingthesuitablyshiftedg-rcluster served relationforstarsandalsostarclusters,as (1974); theireffectivewavelengthsareapproximately5000Á IIIa-J emulsionbehindaWratten4filter,definingband and 6500A.TheyaretiedtotheUBVsystembyrequire- fifth columnsofTable1. distance ofthecluster.Thespatialandmagnitudelimits cluster accordingtothequalityofplatematerialand radius waschosensoastobealwaysgreaterthanR,the cluster. Usually,butnotalways,wehaveincludedgalaxies colors ofgalaxies,asdescribedbelowinthediscussions and rbands.Therelationofthe/-FtoB-Vcolorsis and FbandsareidenticaltotheThuanGunn(1976)g sample radiusforourpopulationstudies(ButcherandOemler follow therelationforstarsandstarclusters. the UBVphotometryofsameobjects,asreportedinvan 1978tf, Z?,1984).Theclustercenterhasbeendefinedasthe 30 666 We havephotometeredgalaxiesonlywithinthecoreofeach Plates oftheseclusterswereobtainedintwobandsonthe © American Astronomical Society • Provided by theNASA Astrophysics Data System A2199 0.030543° R<1.5Mpc=30'17.50.03519. BMISPC A401 0.0748-39°R<1.5Mpc=12'8 18.75 0.03520.BMISPC A400 0.0234-45°R<1.5Mpc=38' 17.0 0.03519.BMIISPC A262 0.0164-25°AX,AT<1.25Mpc=90' 16.00.03519.BMIIISRI A2670 0.0749-69° R<1.5Mpc=12^818.50.03520. BMISPC A2634 0.0322-33° R<1.8Mpc=33'17.50.07518. BMISPC A1904 0.071462°R<1.5Mpc=13'4 19.0 0.03520.BMIISPC A1367 0.021374°R<1.6Mpc=45' 17.0 0.07518.BMIIISRI Hercules ....0.037144°R<1.5Mpc=24'5 18.0 0.03519.BMIIISRI Coma 0.023587°R<1.5Mpc=38' 17.5 0.03519.BMIISPC a 3 BM =Bautz-Morgantype.SR/P =spiralrich/poor.C/Icompact/irregular. Cluster zbSample y amDescription Uni0 BUTCHER ANDOEMLER Clusters Observed TABLE 1 have magnitudesestimatedbyeyebutnocolors. were missedorobviouslymishandledbytheautomaticroutines within approximatelytheS=24.0isophote.Objectswhich relation forstarsandstarclusters.Filledcircles.ComaClustergalaxies. A1367, A2199,andtheComaHerculesclusters.The plate coordinatesusingtransformationsbasedonSAOstars galaxies, andJ-Fcolorswhichrefertothatpartofthegalaxy magnitudes whichapproximatethetotalof cally butwerethencheckedbyeyetocorrectanymisclassifi- cations andaddanymissingobjects.ThefinalresultsareJ reduced usingroutinesverysimilartothosedescribedin obtained, orfrom4mtelescopeplatesinthecaseofA401, estimated usingtheplatesfromwhichphotometrywas on eachplateandshould,ingeneral,beaccuratetoafewarc and theseparationofgalaxiesfromstarsweredoneautomati- Kirshner etal(1983,hereafterKOSS).Thesearchforobjects Open circles,HerculesClustergalaxies.Crosses,A1367 seconds. Themorphologicaltypesofthebrightergalaxieswere s The platesweremeasuredontheYalePDSanddata Fig. 1.—TherelationbetweenJ-FandB-Vcolors.Smoothcurve, Equatorial coordinatesofthegalaxieswerecalculatedfrom Vol. 57 1985ApJS. . .57. .6 65B -1 variation shouldhavetheform proximately thesamesurfacebrightnessindependentofab- galaxies, andiftheerrorsareduetoplatenoise,then magnitude byananalyticexpression.Ifgalaxiesareofap- ment givesusconfidencethatwehaveestimatedtheerrors solute magnitude,whichseemstobetrue,atleastforEandSO accurately. Itisusefultodescribethevariationoferrorwith closely matchtheobservedscatterincolorsofEand used themethodoferrordeterminationillustratedinFigure2 within eachofwhichthedataqualityisverysimilar.Wehave scatter shouldbedominatedbyphotometryerrors,thisagree- SO galaxiesaboutameancolor-magnitudetrend.Sincethat fact, wehavefoundthatthepredictederrorsineachcluster in thecharacteristiccurveofoneplate.Suchscaleerrorsarea show thattheclusterphotometrydividesintothreegroups, present atthislevel(—0.02mag)insomeofourdata. to estimatethecolorerrorsineachofthesegroups.After and thescatteramongdifferentmagnitudedeterminations, color withmagnitudeisascaleerror,probablyduetoanerror constant hazardwithphotographicphotometryandmaybe done thisforseveralclusters.Atypicalresultisshownin brightness ofextendedobjectsandare,forallbutthevery Figure 2,whichpresentsthe“colors”ofgalaxiesmeasuredon ors” ofgalaxiesusingtwoplatesinthesameband.Wehave random colorerrorsmaybeobtainedbymeasuringthe“col- faintest objects,about0.1mag.Averygoodestimateofthe magnitudes aredominatedbyambiguitiesindefiningthe photometry isbasedonphotoelectricintheBV two redplatesoftheComaCluster.Thesteadyincreasein Previous experiencehasshownthatrandomerrorsinthe from 0.03magatF=14.-0.0917.5. The standarddeviationofthecolorsaboutmeanvaries for individualclusters. and JFbands.Detailsofthecalibrationsarediscussedbelow of lowerprecision.Therationaleforthissystemisthat, used inKirshner,Oemler,andSchechter(1978,hereafter assign shouldbenogreaterthantheaccuracywithwhich these ratherdistantgalaxies,theprecisionoftypewe standard Hubblesequence,thereareseveralparallelsequences KOS); itissummarizedinTable12.Inadditiontothe true morphologicaltypeisknown.Absolutecalibrationofthe system usedisthesameelaborationofHubble No. 4,1985 Internal estimatorsofthedataquality,suchasskynoise Photometric errorshavebeenestimatedinseveralways. © American Astronomical Society • Provided by theNASA Astrophysics Data System a =^4dex[0.2(w—m)].(1) E/S0 E In- Sa S0/a SO Pec Sc Sbc Sb Sab 0 Classification System TABLE 12 EL SP • \ EVOLUTION OFGALAXIESINCLUSTERS S rich clusters.Thesignificanceofthiseffecthasbeenconsid- do theE/S0’s,theirmeancolorisvirtuallysame. A ered inanotherpaper(ButcherandOemler1984). similar, thoughlesspronounced,effectisseeninotherspiral- The datafromTables2-11arealsopresentedinFigure3. color. Galaxieswithestimatedmagnitudesandsomeforwhich (in arcseconds),morphologicaltype,Jmagnitude,andJ-F in thecaseofComa,Rood-Baum[1967]number)ifithasone, The othercolumnsgivethegalaxy’sNGCorICnumber(or, galaxies thanareobserved,presumablybecauseofother galaxies, thisexpressionpredictssmallererrorsforbright uncertain byasmuch0.05 mag.Thegalaxiesinthiscluster on JFphotometryoffive galaxies. Thezeropointmaybe spiral galaxies.Althoughtheyhavealargerrangeincolor than bution ofthiscluster,asseeninFigure3,istheredness the right ascension,declination,distancefromtheclustercenter listed inorderofincreasingdeclination.Thefirstcolumnlists Table 1. expression In fact,althoughagooddescriptionoftheerrorsfaint 0.03 maginJ-F.Thereisnopublishedphotometryof this our clustersarepresentedinthesixthandseventhcolumnsof determines thenormalizationofw.ValuesHercules Cluster 17 5112 17 5119 17 515 17 5059 17 5057 17 5049 17 5051 17 5021 17 503 17 4931 17 505 17 4944 17 4944 17 4912 17 4858 17 4853 17 4850 17 4844 17 4825 17 4714 17 4341 17 4955 17 4942 17 4650 17 4631 17 4610 17 44 17 44 17 43 17 43 17 4323 17 4251 48 5340 48 535 48 5231 48 4939 48 5649 48 5551 48 5431 48 5250 48 5130 48 509 48 4947 48 4920 48 58 49 48 592 48 5356 48 539 48 5059 48 5023 48 30 48 24 48 15 48 5749 48 5143 48 515 48 5015 48 4951 48 4942 48 4928 48 495 48 27 48 20 49 48 5920 48 5035 48 36 TABLE 8 679 0 35 0 17 50 50 3 9 1044 1305 1015 1291 1272 1030 1277 1376 1105 1070 1234 1392 1467 1394 1250 1291 1150 1108 1401 1306 1100 1099 1416 1204 1265 1439 1421 1402 1462 1380 1419 980 450 343 245 289 727 637 488 326 393 329 251 202 518 243 771 767 737 426 714 641 681 236 647 283 524 196 596 206 777 653 110 174 172 434 74 75 Type E E? SO Sa SO Sa SOp SOp Type S SO 15.43 16.42 17.65 16.81 14.80 17.72 16.63 16.84 17.46 17.46 15.78 17.17 16.78 16.36 16.74 17.90 16.18 14.21 15.49 17.13 14.68 16.73 17.04 16.52 17.43 17.00 17.20 17.28 15.31 17.16 14.30 15.30 18.24 17.71 18.73 18.98 18.78 18.28 18.57 18.12 16.01 18.54 18.87 18.39 18.69 17.80 18.14 18.91 18.89 18.22 17.73 18.83 17.46 16.54 18.20 18.69 18.31 17.69 18.35 17.52 18.63 17.28 17.51 17.86 18.10 17.85 16.35 18.76 0.78 0.89 0.98 0.87 0.79 1.05 0.97 1.04 J-F 0.92 1.09 1.22 0.92 1.01 1.10 1.06 1.02 0.89 1.11 1.00 1.03 0.87 1.00 1.19 1.24 0.94 1.04 1.06 1.13 0.59 1.13 0.67 0.86 0.79 0.96 0.75 0.52 0.77 0.69 0.82 0.93 1.04 0.71 0.70 0.75 0.91 0.95 0.85 0.96 0.95 0.79 0.75 0.83 0.89 1.00 0.90 0.73 0.74 0.45 0.97 1.02 0.55 J-F 1985ApJS. . .57. .6 65B © American Astronomical Society • Provided by theNASA Astrophysics Data System Object IdentR.A.(1950)Dec(1950)Radius 140 105 109 131 141 110 138 126 147 137 108 106 146 123 139 132 124 136 119 111 102 120 117 115 122 128 142 33 41 53 71 18 29 17 15 74 37 12 16 11 95 96 66 91 85 88 38 58 28 47 48 39 46 55 72 49 30 40 52 54 56 35 60 45 32 13 90 19 65 63 83 86 80 82 84 2 5 9 7 N6047 N6043 11184 N6045 N6050 N6040 N6054 11176 11194 11179 11182 N6044 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 42.4 11.3 21.9 33.1 24.1 46.7 19.5 23.3 27.8 23.0 47.3 25.3 22.2 59.8 25.5 45.7 15.8 24.9 55.5 52.5 12.3 21.1 54.2 20.3 53.3 18.4 17.5 34.7 25.5 37.5 45.5 59.1 24.1 25.0 31.6 16.7 54.4 30.5 40.6 25.9 50.6 29.3 11.3 14.7 12.9 44.9 42.6 23.9 47.1 59.2 22.4 11.9 20.8 59.7 47.2 55.8 51.5 22.9 49.4 12.9 55.2 54.5 46.9 53.0 46.5 12.8 7.6 7.7 6.0 6.6 5.4 6.3 8.3 3.3 7.2 7.9 7.1 7.9 8.1 TABLE 8—Continued 17 546 17 5344 17 5231 17 5458 17 5436 17 542 17 5338 17 5332 17 5318 17 5247 17 5238 17 5231 17 526 17 5134 17 5552 17 5546 17 5515 17 5448 17 5428 17 5426 17 5356 17 5242 17 5227 17 5145 17 5134 17 5626 17 562 17 5524 17 54 17 5315 17 5256 17 5648 17 5623 18 1110 18 148 18 1247 18 1241 18 1236 18 10 18 18 18 18 1359 18 1333 18 1312 18 1140 18 10 18 18 18 18 18 18 18 18 18 17 598 17 581 18 18 18 18 18 18 17 5950 17 5926 17 5912 17 597 17 590 17 58 17 5745 17 5744 17 5738 17 5655 17 5652 18 18 18 17 5713 680 9 46 9 21 9 8 0 31 0 5 8 55 46 13 36 35 41 42 17 32 32 32 28 56 0 5 4 5 8 1070 1273 1007 1148 1187 1132 1276 1187 1246 1259 1273 1239 1138 1269 1016 1182 1373 1070 1285 1354 1053 1415 1336 1389 776 780 790 901 384 361 267 220 662 718 763 987 722 665 339 495 776 275 708 752 901 974 667 792 952 984 983 83 8 887 918 517 166 211 283 876 876 83 8 879 592 734 450 646 631 460 492 563 614 956 950 571 713 731 953 838 78 Pec EL E Sc Sbc Sc SO Sc Sb S- SOp Sc Sc SO/a Sb S Sab SO SO SO Type Sc 17.24 16.91 16.93 17.95 17.55 15.09 17.83 17.38 17.77 15.20 16.95 14.27 16.03 15.22 17.61 16.33 16.31 17.11 16.30 16.71 15.85 15.69 15.00 17.69 17.10 14.55 15.20 15.60 17.88 14.70 17.23 16.30 16.83 17.00 16.47 17.49 15.56 16.39 16.02 16.86 17.59 16.64 17.96 17.30 17.34 15.91 15.75 16.64 14.62 16.16 17.55 17.78 17.47 15.61 16.07 15.00 15.88 15.85 16.88 17.76 15.06 16.58 17.00 14.91 16.05 17.70 15.66 16.55 17.57 17.76 16.90 17.19 17.89 17.51 17.41 15.87 16.22 16.36 17.54 0.97 0.89 1.12 1.19 1.07 1.04 1.04 1.09 0.67 1.17 0.97 0.91 0.88 0.94 1.00 0.97 0.79 0.98 0.95 0.74 1.01 1.04 1.14 1.00 0.74 0.99 0.90 0.62 1.17 1.15 0.99 0.58 0.65 0.96 0.99 1.14 0.97 1.06 0.92 1.09 1.24 0.84 0.84 0.91 0.88 0.87 1.07 0.91 0.98 1.07 0.55 1.03 0.47 0.94 1.09 0.91 0.91 0.89 0.88 1.01 1.17 1.03 1.02 1.12 1.39 1.04 1.21 1.02 1.02 1.04 1.14 0.77 1.19 0.87 1.12 J-F 1985ApJS. . .57. .6 65B American Astronomical Society •Provided bythe NASA Astrophysics Data System Object IdentR.A.(1950)Dec(1950)Radius Object IdentR.A.(1950)Dec(1950)Radius 111 125 132 118 124 149 142 104 134 120 130 104 116 133 118 130 145 127 125 144 121 135 48 47 36 20 43 42 18 71 28 69 78 62 35 64 93 75 58 10 69 89 50 62 43 88 92 31 59 26 87 67 34 21 20 94 73 14 24 99 68 77 44 42 97 5 4 6 N6061 N6057 N6055 11189 16 27 16 27 16 27 16 27 16 25 16 25 16 27 16 24 16 25 16 25 16 26 16 27 16 26 16 26 16 26 16 28 16 26 16 27 16 27 16 25 16 26 16 25 16 26 16 26 16 28 16 26 16 28 16 25 16 26 16 25 16 25 16 25 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 42.8 40.2 27.4 54.2 21.5 28.6 53.1 36.7 34.1 30.1 56.0 39.1 14.8 16.2 20.0 17.3 53.4 24.1 34.0 40.4 53.3 58.7 48.1 12.4 12.0 14.0 10.1 11.4 55.3 15.4 57.0 12.0 27.8 27.3 12.8 19.4 40.1 20.2 22.6 21.8 14.7 51.2 30.1 37.6 38.4 13.7 45.5 43.8 10.8 17.3 25.0 25.8 17.8 60.0 46.6 34.4 47.3 26.2 5.7 5.4 1.3 5.0 1.5 7.9 2.7 0.3 1.6 6.8 TABLE 8—Continued 39 2542 39 2538 39 2531 39 24 39 17 39 17 39 2617 39 2544 39 2437 39 2435 39 2319 39 23 39 22 39 2153 39 2131 39 2053 39 20 39 1929 39 16 39 16 39 1529 39 2637 39 2151 39 20 39 1530 39 1456 39 1446 39 1433 39 14 39 12 39 11 39 12 18 2950 18 2949 18 28 18 2741 18 2651 18 2923 18 2648 18 2641 18 2639 18 2458 18 2417 18 24 18 243 18 230 18 2258 18 2244 18 2123 18 1941 18 1916 18 195 18 2110 18 2022 18 19 18 58 18 56 18 1759 18 1746 18 13 18 1728 18 1624 18 167 18 1533 18 1530 18 158 18 1421 18 1441 Abell 2199 TABLE 9 681 34 38 30 49 38 14 39 53 6 0 1092 1503 1766 1418 1350 1007 1412 1244 1393 1338 1390 1553 1033 1170 1181 1202 1264 1421 1388 1382 1488 1453 1737 1619 1661 1048 1744 1498 1658 1762 1392 1374 1353 1409 1202 1360 1347 1280 1450 1215 1303 1037 1133 1295 1064 1385 1424 1221 1014 1156 1228 1401 864 856 950 686 890 850 928 657 651 907 626 937 876 535 615 453 Type E EL SO S- SBc SO Sc SO SO Sc S+ E SO Sb Sc E SO/a SO/a Sbc Type 16.91 16.61 15.78 16.25 17.02 16.39 17.37 16.11 16.65 15.89 15.63 16.98 16.07 17.04 15.21 15.44 15.89 15.64 17.13 15.23 16.60 14.14 17.15 17.27 16.30 17.11 16.63 16.76 16.29 16.17 15.80 16.84 14.80 17.21 16.44 17.48 15.98 17.03 16.94 16.18 16.38 17.71 16.60 15.62 15.44 17.50 14.34 15.74 17.66 17.05 17.92 17.60 15.27 15.25 16.68 15.03 17.15 15.42 16.61 17.58 14.57 17.91 16.76 17.54 17.73 17.12 15.92 16.00 0.67 0.97 0.92 0.49 0.98 0.94 0.97 J-F 0.89 0.85 1.02 0.73 0.77 0.93 0.78 0.92 0.82 0.88 0.97 0.73 0.94 0.96 0.90 1.05 1.09 1.32 1.10 0.85 1.09 0.86 1.04 1.09 0.89 0.90 0.79 1.06 0.95 0.66 1.04 1.08 1.19 0.93 0.76 0.88 0.74 0.79 1.06 1.03 0.90 1.04 1.09 0.58 0.53 1.12 0.78 1.04 1.08 1.02 0.72 1.03 1.16 0.68 1.00 0.85 0.81 1.05 J-F 1985ApJS. . .57. .6 65B © American Astronomical Society • Provided by theNASA Astrophysics Data System Object IdentR.A.(1950)Dec(1950)RadinsTypeJJ—F 152 1627 156 1627 155 1626 147 1626 109 1626 129 1628 116 1626 163 1627 106 1627 138 1624 141 1626 139 1627 151 1625 123 1627 105 1626 148 1626 161 1627 117 1626 158 1625 100 1627 101 1626 110 1626 144 1626 154 1627 140 1627 136 1624 135 1627 157 1627 119 1625 115 1628 153 1625 44 1625 70 1625 34 1627 17 1628 52 1625 94 1627 96 1626 30 1627 31 1624 67 1625 79 1624 60 1629 16 27 63 1625 23 1626 15 1626 27 1629 25 1626 46 1626 24 1626 61 1627 51 1627 29 1627 91 1624 72 1626 98 1626 66 1627 41 1626 57 1628 95 1627 12 1626 99 1627 55 1625 73 1627 97 1628 53 1627 74 1626 82 1625 92 1625 83 1625 84 1626 87 1626 2 N61581625 4 1627 7 1628 9 1627 1 N61661626 8 1625 51.9 394428704 13.6 3929151326 17.5 392645884 53.9 392853936 49.7 3929491449 40.5 392737891 27.3 392731816 46.2 3944201299 26.1 3941321044 55.6 394120103 46.6 39411806 20.5 3940341669 35.7 3929531713 33.1 3929251127 59.0 392859908 47.7 392859643 49.5 3928481588 24.7 394414428 52.8 394431449 17.9 39443516 43.3 394352599 49.2 394038773 24.1 393619384 52.0 39366214 52.0 393524776 23.9 3932381767 20.6 3932201178 48.2 393126917 57.5 39309875 57.6 392921905 41.4 394349575 34.3 394332974 51.4 394351330 52.0 3942571337 36.9 393224647 51.0 393138481 33.3 393041694 39.7 394349560 40.9 394249261 36.3 3942271623 40.3 394044193 28.8 39471072 31.2 3913286 16.6 393826935 20.4 3937591105 48.0 393749140 10.0 393623254 20.4 393328468 48.1 393381520 59.6 392950588 15.8 394241501 31.3 394135422 13.0 394032499 51.7 392549 53.8 39385152 48.0 393754140 24.7 393752373 54.2 393318379 13.8 39438292 10.2 394011167 27.6 39406328 55.5 39448 56.2 393738118 56.8 393649168 2.9 3934301336 3.7 393415335 8.6 392657928 1.2 3935246 0.9 390635 1.6 393450295 0.5 3943241354 3.1 39438225 1.9 393246417 9.6 394430612 6.5 394330261 0.2 394078 2.6 393812115 1.4 393729144 1.4 39413105 TABLE 9—Continued 682 E 14.030.97 EL 15.600.91 E 15.121.05 E 15.301.01 E 14.531.00 EL 15.741.10 SO/a 15.201.03 Sc 15.960.62 S- 14.140.98 SO 15.50 SO 15.521.06 SO 15.531.08 SO 15.950.91 SBa 14.781.03 SO 15.171.07 SO/a 15.261.09 SO 15.831.00 SO 15.420.96 Sc 15.960.61 cD 12.711.00 SO 15.30 Sa 14.390.96 SO 15.871.13 SO/a 15.001.03 16.27 0.96 16.15 0.72 16.70 0.94 17.42 0.87 16.08 1.02 16.23 1.05 16.69 1.02 17.35 0.89 16.21 1.09 16.62 0.85 16.46 0.89 16.29 1.05 17.46 0.93 16.41 0.74 17.39 0.62 17.43 0.31 17.49 0.85 16.70 16.82 0.98 16.46 0.77 17.48 0.98 16.91 0.83 16.90 16.80 0.95 17.22 0.81 16.70 16.29 1.04 17.10 17.16 0.85 16.30 16.06 1.16 17.30 16.10 1.21 17.41 0.92 17.39 0.80 17.20 0.73 17.25 0.80 17.38 1.01 16.04 0.93 17.23 0.72 16.70 17.17 0.85 16.64 0.89 16.71 0.92 17.45 0.94 17.01 0.65 16.83 1.08 16.86 0.87 16.50 16.67 1.06 16.80 17.36 0.94 16.65 0.90 16.96 0.75 16.59 0.86 1 985ApJS . 57 . . 665B © American Astronomical Society • Provided by theNASA Astrophysics Data System Object IdentR.A.(1950)Dec(1950)Radius Object IdentR.A.(1950)Dec(1950)Radius 103 145 122 159 146 100 114 160 162 143 112 133 128 131 107 102 121 126 150 127 113 137 108 42 26 41 34 17 30 54 39 56 13 59 22 37 26 49 61 75 54 32 77 14 11 19 21 56 50 45 39 40 94 76 33 68 65 38 88 98 81 86 90 85 80 86 3 6 23 36 23 34 23 36 23 35 23 34 23 34 23 37 23 34 23 36 23 35 16 27 16 28 16 27 16 26 16 27 23 35 23 37 23 34 23 35 23 35 23 35 16 26 16 28 16 27 16 28 16 28 16 26 16 25 16 27 16 28 16 24 16 28 16 27 16 27 16 28 16 27 16 25 16 28 16 26 16 27 16 28 16 26 16 27 16 26 16 27 16 26 16 27 16 27 16 29 16 27 16 27 16 26 16 26 16 28 16 25 16 27 16 26 16 24 16 27 16 27 16 29 16 27 16 26 16 27 16 27 16 27 16 29 16 28 57 .5 39.4 14.9 55.7 10.6 24.6 16.2 40.9 30.6 31.4 42.3 54.3 37.5 34.6 59.7 15.6 59.7 14.4 35.2 42.3 37.8 50.1 53.1 58.9 37.0 34.6 29.0 50.9 38.3 29.0 24.4 42.0 47.1 50.8 50.8 56.3 34.9 48.5 53.2 29.8 57.6 21.2 31.0 57.3 16.4 58.8 54.2 11.4 14.6 54.5 17.1 15.2 4.3 2.7 6.2 2.7 5.4 7.6 3.5 4.8 5.1 1.2 1.2 1.9 2.5 1.7 8.3 8.6 TABLE 9—Continued 26 2454 26 2125 26 2027 26 1716 26 2315 26 1913 26 1814 26 1343 40 26 2435 26 2342 26 132 40 40 26 2934 26 29 26 28 26 13 26 250 40 40 40 40 39 5521 40 40 39 58 39 57 39 57 39 5731 39 5727 39 5650 39 5642 39 5551 39 5519 39 5459 39 5446 39 5322 39 5241 39 5134 39 510 39 5038 39 5011 39 4943 39 4940 39 4938 39 5641 39 56 39 5549 39 5224 39 5154 39 513 39 5047 39 4828 39 4737 39 46 39 4554 39 45 39 45 39 4447 39 44 39 495 39 4651 39 4649 39 4617 39 4518 39 4455 39 4453 Abell 2634 TABLE 10 683 20 50 34 21 40 23 41 26 34 33 3 1 7 8 1437 1340 1997 1957 1009 1221 1910 1611 1728 1924 1666 1520 1571 1678 1740 1482 1251 1785 1679 1484 1412 1381 1765 1672 1420 1746 1143 1024 1665 1236 1661 1030 1206 1003 1567 1735 1495 1082 1481 1135 1639 1010 1724 1523 1431 1480 531 431 514 748 641 607 604 579 385 368 315 993 703 994 534 410 322 935 932 939 940 843 Type S+ SO SO EL EL E so SP s+ Sb SO Sbc SO Sc SO SP SO SO S+ Type 16.26 15.98 17.32 17.27 16.62 15.80 16.31 16.31 15.47 16.72 17.14 17.11 17.33 16.91 16.64 16.15 16.73 17.32 16.31 16.00 15.08 15.25 15.37 15.24 17.00 17.47 16.07 17.35 17.28 15.10 16.53 16.05 17.13 15.59 16.19 15.83 16.71 15.64 16.53 16.85 17.48 16.45 15.21 14.10 16.85 16.42 16.62 17.09 16.23 15.94 17.05 15.64 15.94 16.85 15.68 17.00 14.81 14.26 16.31 17 .49 15.67 17.13 16.81 16.82 15.55 17.37 17.18 17.04 J-F 1.17 0.97 0.93 1.08 0.88 0.87 0.68 1.08 1.30 1.01 1.09 1.11 0.76 1.16 1.12 1.15 1.04 0.86 0.97 0.70 0.96 0.91 0.83 0.96 0.62 0.84 0.53 0.49 0.73 0.76 0.93 1.04 0.83 1.03 1.00 1.14 0.92 0.78 0.66 1.02 0.81 0.67 1.00 0.87 0.97 0.94 0.86 1.10 0.91 1.10 1.05 1.01 0.85 0.88 0.83 1.10 0.92 0.95 1.06 0.82 0.98 1.07 0.82 0.88 0.99 0.92 1.01 0.86 J-F 1985ApJS. . .57. .6 65B © American Astronomical Society • Object IdentR.A.(1950)Dec(1950)Radins 106 103 104 107 101 109 102 108 48 40 21 29 69 35 14 31 33 32 67 12 53 19 65 62 79 64 47 43 38 51 72 22 24 28 13 99 50 78 49 15 60 44 92 71 66 90 37 59 27 55 18 10 36 45 20 77 58 70 76 83 11 57 95 82 84 96 81 87 89 4 2 7 3 6 1 8 N7728 N7720 15342 23 36 23 36 23 38 23 38 23 36 23 36 23 35 23 37 23 37 23 36 23 35 23 38 23 36 23 34 23 36 23 36 23 35 23 37 23 38 23 38 23 36 23 36 23 36 23 38 23 37 23 37 23 38 23 36 23 36 23 37 23 38 23 36 23 35 23 35 23 33 23 37 23 36 23 35 23 35 23 34 23 36 23 35 23 35 23 35 23 34 23 35 23 38 23 37 23 35 23 35 23 37 23 34 23 33 23 37 23 35 23 36 23 33 23 35 23 36 23 36 23 36 23 36 23 35 23 34 23 37 23 37 23 38 23 36 23 35 23 36 23 36 23 35 23 34 23 35 23 35 23 35 25.1 48.4 12.6 16.9 31.1 36.4 39.3 31.7 47.4 47.2 45.7 12.7 10.9 19.5 11.7 51.9 12.4 24.9 16.2 28.0 58.5 34.4 34.8 51.4 15.7 32.5 25.7 41.3 30.1 33.5 16.4 40.6 14.2 23.3 25.7 31.7 48.2 46.8 18.0 18.7 11.5 57.5 56.6 55.8 39.1 46.7 31.0 22.1 48.1 49.7 46.3 43.1 12.4 50.3 59.0 44.2 16.2 37.9 13.8 57.2 20.1 56.4 58.6 2.8 4.8 3.0 1.3 6.5 3.1 2.6 4.0 0.1 5.8 8.5 8.6 8.3 TABLE 10—Continued Provided bythe NASA Astrophysics Data System 26 5746 26 5658 26 584 26 5620 26 5619 26 5541 26 5419 26 5118 26 5058 26 4943 26 3359 26 3353 26 3318 26 3318 26 3221 26 5721 26 5637 26 5620 26 5439 26 5435 26 5317 26 5253 26 5118 26 516 26 4932 26 4928 26 3340 26 32 26 3216 26 3043 26 2946 26 5533 26 5352 26 5342 26 5315 26 532 26 5213 26 5029 26 506 26 4737 26 4531 26 395 26 3424 26 3225 26 5256 26 5044 26 4918 26 4743 26 4549 26 4258 26 4217 26 428 26 4131 26 4051 26 3712 26 4849 26 4845 26 4736 26 4711 26 46 26 4512 26 458 26 451 26 4419 26 443 26 4228 26 428 26 418 26 3941 26 3452 26 34 26 4514 26 385 26 36 26 3611 26 3527 684 1008 1590 1974 1818 1598 1849 1052 1396 1338 1314 1607 1827 1904 1970 1390 1074 1904 1270 1817 1814 1496 1916 1872 1633 1548 1408 1526 1774 1175 1099 1087 679 673 710 795 495 798 660 713 457 347 516 205 773 544 580 723 413 624 518 207 416 939 146 288 179 607 688 978 182 465 132 750 147 199 685 460 997 505 551 624 801 858 816 13 90 Type EL EL SO/a SO E EL SO/a SP SO? cD SO SO SP SO 15.49 15.33 17.43 16.03 14.96 16.81 16.50 15.00 17.48 17.40 15.48 16.79 16.99 16.10 16.08 16.34 15.42 14.00 14.53 16.88 16.84 16.15 14.50 15.20 15.23 16.26 16.59 16.48 16.51 16.96 16.51 17.22 16.88 15.00 15.91 17.42 16.57 16.71 17.03 17.21 16.70 15.47 17.34 15.20 17.30 17.28 16.42 15.60 16.93 17.33 16.72 16.78 17.49 16.23 16.80 15.59 16.23 15.85 17.04 16.64 15.20 16.20 16.42 16.65 17.48 16.92 17.00 15.49 17.13 17.15 15.88 16.67 17.35 17.01 16.84 13.46 0.88 1.24 1.02 1.23 1.06 0.80 1.23 0.83 1.11 1.17 1.05 1.28 1.02 1.27 J-F 1.34 1.22 0.94 1.34 1.07 1.10 1.11 1.32 1.02 0.90 1.11 1.21 1.22 1.11 0.55 1.09 1.15 1.32 1.07 1.04 1.33 1.25 1.11 1.11 1.24 1.19 1.15 1.11 1.14 1.12 1.14 1.07 1.22 1.25 1.28 1.24 1.27 1.21 1.26 1.11 1.04 1.11 1.12 1.11 1.04 1.06 1.30 1.11 1.16 1.28 1.09 1.28 1.20 1.18 1.28 1.33 1^985Ap JS . . . 5;7 . . 665B © American Astronomical Society • Provided by theNASA Astrophysics Data System Object IdentR.A. Object IdentR.A.(1950)Dec(1950)Radins 118 2351 100 2351 104 2351 105 114 2351 101 2351 111 2351 121 2351 105 2350 127 2351 117 2352 103 2351 126 2352 124 2351 43 2351 40 2351 20 2352 25 24 2352 33 2351 63 74 2351 56 2351 22 2351 64 2351 58 2352 57 2351 49 2351 41 2351 74 16 97 91 73 52 46 23 92 2351 90 2351 77 2351 79 2351 12 2351 68 2351 65 2351 19 2351 54 2350 25 2350 11 2351 17 2351 30 2351 94 2351 18 2351 91 2351 14 2351 62 2351 93 68 95 2351 99 2351 96 2351 85 80 7 2351 9 5 23 36 23 35 23 37 23 36 23 36 23 37 23 35 23 36 23 38 23 34 23 35 23 36 23 36 23 37 23 36 23 34 23 35 43.0 28.1 32.0 -10428110 42.7 40.2 26.0 47.3 -104211118 45.6 -10421996 44.0 18.6 38.6 42.4 30.9 27.3 42.9 -10424172 49.4 -10439167 39.4 -10432089 50.3 11.9 30.2 -104230141 45.2 -10423697 27.7 -104239179 41.4 -10431287 36.4 -104346125 40.4 -10452192 28.4 -104521267 30.8 -104614293 37.1 -10546738 20.0 14.2 -104233515 58.8 -104258293 35.9 -104428167 39.3 -104429159 28.4 -104455247 20.8 -104523348 36.0 -10462257 18.7 -10471437 58.6 -1043304 28.6 -104435230 17.5 -104453590 52.7 -104539300 51.8 -104557745 31.8 -104620293 36.1 -104632286 17.6 -104632429 42.9 -104639293 55.6 -104659389 53.5 -104713752 10.6 -104741577 56.5 -104823465 44.3 -104918453 45.1 -104942479 34.0 -105128585 10.9 -105216757 55.1 -104819763 11.3 -105031668 4.7 5.2 -10428381 0.9 5.4 5.6 -104225499 4.4 -10459553 1.1 -1044592 0.4 -105027601 8.3 -105036700 TABLE 10—Continued Dec(1950) Radins Abell 2670 27 27 1711 27 27 27 1615 27 27 27 27 27 27 27 27 27 27 26 5925 26 5918 TABLE 11 685 9 0 8 16 31 23 17 56 47 39 38 21 58 53 0 2002 1942 1963 1146 1141 1957 1583 1695 1048 1385 1314 1632 1706 1117 979 932 886 EL E Type JJ-F EL EL Sa? Type 15.68 16.89 15.43 16.74 17.42 17.32 15.16 17.21 17.10 16.89 16.58 17.25 16.46 15.59 16.99 14.75 16.77 0.92 16.68 0.84 18.36 0.46 18.43 0.97 18.49 0.78 17.14 0.73 18.39 0.61 18.44 0.85 16.90 0.76 17.59 0.71 18.06 0.41 16.81 16.23 0.87 18.14 0.83 18.41 0.54 17.19 0.81 17.12 0.68 17.01 0.83 18.03 0.58 17.51 0.90 17.84 0.78 17.87 0.95 16.49 0.99 17.66 0.69 18.04 0.70 18.17 0.89 18.15 0.73 17.32 0.90 18.02 0.37 17.42 0.89 18.48 1.18 16.42 0.92 16.52 0.88 16.55 0.86 17.77 0.69 18.02 0.82 16.73 0.78 17.59 0.80 18.14 0.84 18.26 0.76 17.56 0.76 18.16 0.52 17.55 0.72 17.61 0.85 18.05 0.91 18.12 0.73 16.55 0.91 16.55 16.80 0.78 0.69 0.61 0.96 0.76 0.55 1.29 1.18 1.12 1.06 1.12 1.31 1.13 0.72 1.24 1.11 J-F 1985ApJS. . .57. .6 65B © American Astronomical Society • Provided by theNASA Astrophysics Data System Object IdentR.A.(1950)Dec(1950)Radius 115 109 119 113 122 112 102 123 107 125 116 110 120 106 108 76 31 45 21 72 59 29 16 52 67 42 70 36 27 37 86 87 80 75 69 93 81 84 47 85 48 61 28 32 23 26 66 53 73 50 10 98 39 38 60 15 97 88 89 51 34 35 78 63 82 71 55 13 83 46 1 3 6 8 2 4 5 9 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 50 23 51 23 51 23 51 23 51 23 50 23 51 23 51 23 50 23 51 23 51 23 51 23 51 23 51 23 51 23 52 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 52 23 51 23 51 23 51 23 51 23 51 23 51 23 52 23 52 23 51 23 51 23 51 23 51 23 52 23 52 23 51 23 52 23 51 23 51 23 51 23 52 23 51 23 52 23 52 23 51 23 52 23 51 23 51 23 52 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 51 23 52 23 51 23 51 18.5 39.3 44.1 35.7 47.1 32.6 42.6 20.3 32.6 34.8 40.4 42.8 40.8 36.9 43.7 39.3 29.4 22.8 34.3 39.0 44.6 39.3 53.0 14.0 22.8 50.4 52.4 51.6 53.0 10.0 50.3 32.5 25.9 22.8 33.6 49.0 21.4 40.0 36.2 30.4 19.2 39.0 41.9 45.1 31.3 16.9 38.4 14.6 29.5 44.0 29.1 14.6 23.6 12.2 23.8 19.9 40.5 37.9 42.2 14.4 43.7 21.6 16.6 27.6 56.6 22.6 56.5 44.0 0.9 6.1 2.4 3.8 7.7 2.7 3.4 7.0 5.4 9.9 TABLE 11—Continued -10 4148 -10 4151 -10 4151 -10 4157 -10 404 -10 4019 -10 414 -10 4153 -10 4157 -10 406 -10 4021 -10 4029 -10 4042 -10 417 -10 4111 -10 4118 -10 4130 -10 4138 -10 3919 -10 3952 -10 401 -10 4056 -10 4059 -10 4123 -10 4132 -10 398 -10 3929 -10 4138 -10 3859 -10 397 -10 3918 -10 3951 -10 393 -10 3825 -10 3856 -10 3659 -10 3722 -10 3753 -10 389 -10 3828 -10 3557 -10 3618 -10 3642 -10 3738 -10 3836 -10 3543 -10 3553 -10 3611 -10 3643 -10 3656 -10 3731 -10 3443 -10 3511 -10 3538 -10 360 -10 365 -10 344 -10 3431 -10 3516 -10 3253 -10 33 -10 33 -10 3440 -10 3136 -10 3148 -10 3218 -10 3248 -10 33 -10 33 -10 3414 -10 3421 -10 3053 -10 3152 -10 3253 -10 33 -10 308 -10 3034 -10 3052 44 16 41 47 8 307 292 210 331 212 114 280 118 133 728 101 111 693 375 100 265 462 292 738 139 103 493 182 167 220 283 339 293 281 292 353 210 200 307 302 296 673 415 374 353 362 678 665 700 576 666 509 589 627 553 761 581 487 548 547 667 761 541 533 566 643 595 748 658 657 616 678 680 716 69 25 22 68 51 65 52 80 1 Type 14.99 17.81 16.93 16.68 16.53 18.37 18.42 17.56 16.88 17.91 16.29 18.20 15.88 17.92 17.20 17.73 17.93 17.87 17.70 17.36 17.06 17.79 17.68 18.44 16.21 17.65 18.31 17.88 17.17 17.90 18.03 17.05 16.84 16.97 18.11 16.85 18.44 17.99 17.28 18.31 18.15 17.57 17.27 17.62 17.36 18.19 17.95 16.42 18.24 17.56 16.52 17.73 18.38 17.89 16.75 18.06 16.84 18.48 17.37 17.07 18.43 17 .06 17.85 17.59 17.36 17.90 15.70 16.51 17.01 17.72 18.18 17.43 17.04 15.95 17.24 18.20 16.18 16.30 0.59 1.04 0.84 0.80 0.90 1.02 0.69 0.75 0.94 0.93 0.46 0.89 0.60 1.11 0.77 0.80 0.65 0.74 0.76 0.95 0.74 0.75 0.85 1.16 0.67 1.15 0.84 1.05 0.94 J-F 0.68 0.90 0.51 0.80 0.56 0.82 0.86 0.80 0.89 0.85 0.75 0.85 0.98 0.93 0.65 0.85 0.63 0.81 0.82 0.86 0.90 0.89 0.86 1.10 0.80 0.64 0.70 0.94 0.84 0.74 0.71 0.93 0.61 0.96 0.61 0.71 0.94 1.17 0.82 0.73 0.86 0.82 0.89 1.07 0.64 0.97 0.98 0.82 1.06 1985ApJS. . .57. .6 65B B-V photometryofLdV and ofBothun,Schommer, poorest oftheten.Acomparison ofourJ-Fcolorswiththe published photometryofthiscluster. galaxies fromthecompilationofLongoanddeVaucouleurs (1983, hereafterLdV).Thecolorzeropointshouldbeaccurate cluster memberandisuncertainto0.05mag.Therenoother Hoessel, Gunn,andThuan(1980)photometryofthebrightest Sullivan (1984)isincludedin Figure1.Thestandarddeviation to 0.04mag.Ourphotometryofthisclusterisamong the of theJ-Fcolorsabout expectedrelationis0.10mag, latitude. However,HImeasurementssuggestthatgalactic slightly higherthanthepredicted dispersionof0.08mag. extinction initsdirectionmaybequitehigh(Bothun1984). are unusuallyredforaclusterofmoderatelyhighgalactic unclassified. The calibrationofA1367isbasedonBVphotometry14 The zero-pointcalibrationofA401isbasedonlyonthe Fig. 3.—Color-magnitudedistributionsofgalaxiesinthe10clusters.Opencircles,EandSOgalaxies.Crosses,spiralsirregulars. Filledcircles, © American Astronomical Society • Provided by theNASA Astrophysics Data System d) Abell1367 c) Abell401 EVOLUTION OFGALAXIESINCLUSTERS included inFigure1.Thescatter'mJ-Fhasastandard photometry revealedacolorscaleerrorinthelatterwith 0.02 mag.ThecomparisonoftheJ-FandÆ-Fcolors is maximum amplitudeof0.15mag.Thiswascorrectedin the Godwin etalAsidefromthis difference,theagreementbe- errors inthephotoelectricphotometry. colors of0.04mag,ifweassumeareasonablevaluefor the deviation of0.08mag,or0.05magifthefourbluestobjects sive photographicphotometryoftheComaClusterin 5 are excluded.Thisisconsistentwithanexpectederrorin our final photometry.Thecolorzeropointshouldbeaccurate to Comparison ofthisphotometrywiththerawphotographic tric photometryof54galaxiesfromSandage(1972)andLdV. probably duetotheparticular choiceofzeropointusedby by 0.24mag.Thereason for thisshiftisunclearbut curve isthecalculatedrelation betweenthecolors,shiftedup of colormeasurementsispresented inFigure4.Thesmooth and F(whichtheycallr)bands.Acomparisonofthetwo sets J The ComaphotometrywascalibratedusingBVphotoelec- Godwin, Metcalfe,andPeach(1982)havepublishedexten- e) TheComaCluster 687 1985ApJS. . .57. .6 65B 0.0 0.5 0.0 0.5 1.0 1.5 1.0 1.5 _i iIMrJi_i_ig 1..1-1 11.J.1IiJ-L.1.JJ HERC. CL. COMfi CL. © American Astronomical Society • Provided by theNASA Astrophysics Data System 13. 15.17.19. + -H-t + *“yt Fig. 3—Continued ::fi 1904 J i »I1■>'!^ fl 2199 + '~ * ’*5;^ . •*V«* + ®i ® . •*;‘r . .•'A* 17. v • A, 19, 1985ApJS. . .57. .6 65B line is0.07mag,somewhatlarger thanthedispersionof0.05 in Figure1.ThestandarddeviationofJ-Faboutthemean photometry of22galaxiesfromLdV;thezeropointshould be mag predictedfromtheestimated errorsinthephotoelectric accurate to0.02mag.TheB-VdataforHerculesisincluded and photographicphotometry. photometry oftwogalaxies;theuncertaintyincolor zero point isabout0.04mag.Therenopublishedphotometry of relation, shiftedupby0.24mag. this clusterotherthanthatsummarizedinOemler(1974). ter galaxiesandourJ-Fcolors.Thesmoothcurveistheexpected between theirisophotalandourtotalmagnitudesofthese linearity atthefaintendisprobablyduetodifference a =0.18mag,comparedwith0.16magpredictedfromour faint galaxies.Otherwise,theagreementisquitesatisfactory; of Godwinetal.ispresentedinFigure5.Thedeparturefrom values aregiveninTable7withinparentheses. better, thanhadbeenestimated.Wehaveusedthepublished larger thanthescatterpredictedfromourerrorsaloneandis and theirerrorestimates(0.100.13magrespectively). ( a=0.15)intheGodwinetalcolorsalone.Apparently 0.04 magatJ=14.to0.07/17.5.Thisisscarcely B-V andB-Rphotometry,therelationbetweenthese standard deviationofJ-Faboutthemeanlinerangesfrom tween thetwosetsofphotometryisremarkablygood.The some ofourgalaxieswithoutmeasuredJ-Fcolors.These and J-FshowninFigures14,toestimatecolorsfor Godwin etal.colorsaremuchbetter,andourssomewhat smaller thanthescatterpredictedfromstatederrors Calibration oftheHerculesphotometryisbasedonBV The calibrationofA1904isbasedonJFphotoelectric Fig. 4.—RelationbetweenGodwinétal.B-RcolorsofComaClus- A comparisonofourJmagnitudeswiththeB © American Astronomical Society • Provided by theNASA Astrophysics Data System g) TheHerculesCluster /) Abell1904 J-F EVOLUTION OFGALAXIESINCLUSTERS lished relationsbetweenB-VandU-BV-Rforgal- relation inFigure1betweenB-VandJ-Ftheestab- galaxies andourJ-Fcolors.The smoothcurveistheexpectedrelation. expected relationbetweenthecolors,calculatedusing Cluster GalaxiesandourJmagnitudes. axies. ThedeviationofpointsfromthelineisplottedversusJ try iscomparedwiththeirsinFigure6.Thesolidlinethe (1978). Thecolorzeropointshouldbegoodto0.03mag. a largenumberofearly-typegalaxiesinA2199.Ourphotome- and BVphotometryoffivegalaxiesfromStrom Strom andhavemeasuredphotographicU-Rcolorsof Fig. 6.—RelationbetweenStrom andStromU-RcolorsofA2199 Fig. 5.—RelationbetweenGodwinétal.BmagnitudesofComa A2199 wascalibratedusingJFphotometryoftwogalaxies h) Abell2199 689 1985ApJS. . .57. .6 65B photometry ofthebrightestclustermember;colorzero is basedonJFphotometryoftwogalaxies;thezeropoint less accuratethanthoseofmostotherclusters.Thecalibration uncertain to0.05mag. expected relation. of A2199galaxiesandourapparent Fmagnitudes;straightlineisthe photometry isatfault.InFigure8wecompareourFmagni- is linearwithascatterof=0.16mag.Thezeropointagrees parent fainterthan16.0;itisnotobviouswhichsetof perfect matchofthetwoplatesandcouldnotbeusedforthis 48 inchSchmidttelescope,thetwoplateshaveslightlydiffer- with thatexpectedtobetterthan0.03mag. magnitude inFigure7.Asystematiccolordifferenceisap- cluster. Becauseofthis,thecolorsA2634galaxiesare ent scales.Ourstandardphotometryroutinesdependona of thefieldflattenerusedwith5X7inchplatesonPalomar cm) andone10inch(25.4squareSchmidtplate.Because tudes withtheStromandRphotometry.Therelation magnitude. 690 The calibrationofA2670isbasedonSandage’s(1973) Fig. 8.—RelationbetweenStrom andStromabsoluteRmagnitudes A2634 wasphotometeredonone5x7inch(12.7X17.78 Fig. 7.—Deviationofpointsin6fromthecurve,vs.theirJ © American Astronomical Society • Provided by theNASA Astrophysics Data System j) Abell2670 i) Abell2634 Mr BUTCHER ANDOEMLER but thisisnotpossibleformostofourclustersbecausetheir point isuncertainto0.05mag.Dressier(1978)hasalso latitude, asufficientlyaccurateestimateoffieldcontamination large angularsizeleaveslittleorno“field”areaontheplates. position oftheclusterisknown.Ideallythisshouldbede- color and0.25inmagnitude. distribution ofthedensitygalaxiesversuscolorandmagni- may beobtainedfromameandeterminationofthe field published Fbandphotometryofthiscluster.Acomparison galaxies. degree, ispresentedinTable13,binnedintervalsof0.1 in fainter magnitudesbyaremeasurementoftheNP7and SP4 surveys ofKOSandKOSS.Thesehavebeenextended to galaxy densityathighlatitude.Forthiswehaveused the nitudes. mag, closetotheexpectedvalue.Thedifferenceinzeropoint of thephotometryispresentedinFigure9.Thescatter0.17 AST81-19986. lished dataandBillvanAltena fortheavailabilityofYale tude. Thisdistribution,innumbersofgalaxiespersquare fields. Fromthesedatawehaveconstructedasmoothed,mean tion oftheseclustersissmall.Sincemostareathighgalactic termined beyondbutintheimmediatevicinityofeachcluster, and theslightupturnatfaintendarebothprobablydueto PDS. Thisresearchwaspartially supportedbyNSFgrant practical nornecessary.Astatisticalcorrectionforfieldcon- the differencebetweenDressler’sisophotalandourtotalmag- fine ofsighttothecluster.Redshiftmeasurementswillallow contaminated byforegroundandbackgroundgalaxiesonthe one toeliminatetheseobjects,butinmanycasesthisisneither tamination canbemadeifthedensityoffieldgalaxiesat We aregratefultoGregBothum fortheuseofhisunpub- Fortunately, becausetheyarenearby,thefieldcontamina- Fig. 9.—RelationbetweenDressler’sandourFmagnitudesforA2670 The apparentgalaxypopulationofaclusterisalways IV. FOREGROUNDANDBACKGROUNDGALAXIES Vol. 57 1985ApJS. . .57. .6 65B Augustus Oemler,Jr.:YaleUniversityObservatory,P.O. 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J 19.00 18.75 18.50 18.25 18.00 17.75 17.50 17.25 17.00 16.75 16.50 16.25 15.50 16.00 15.75 15.25 15.00 14.75 14.50 14.25 13.50 14.00 13.75 © American Astronomical Society • Provided by theNASA Astrophysics Data System 0.0 0.10 0.00 0.21 0.00 0.07 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 0.30 0.65 1.05 0.31 0.67 0.16 0.38 0.03 0.10 0.01 0.02 0.00 0.00 0.12 0.00 0.06 0.01 0.05 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.03 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 Background Corrections(GalaxiesperSquareDegree) EVOLUTION OFGALAXIESINCLUSTERS ,4 0.50 1.24 1.66 0.51 0.74 0.95 1.24 0.36 0.63 0.15 0.52 0.07 0.27 0.38 0.44 0.17 0.23 0.10 0.11 0.02 0.07 0.01 0.06 0.00 0.01 0.01 0.05 0.00 0.02 0.00 0.03 0.02 0.01 0.01 0.00 0.00 0.00 0.00 6 0.70 2.80 4.66 1.50 1.91 0.68 0.99 0.85 0.77 0.76 0.69 0.68 1.33 0.40 0.65 0.26 0.38 0.13 0.20 0.16 0.26 0.09 0.14 0.14 0.21 0.04 0.09 0.02 0.08 0.01 0.05 0.04 0.05 0.04 REFERENCES 0.01 0.02 0.01 0.04 0.00 0.01 0.00 0.01 0.00 TABLE 13 J-F .1981,Astr.Ap.Suppl.,46,79. .1973,Ap.J.,183,711. van denBergh,S.1976,Ap.J.,206,883. 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