1985ApJ. ..291 .... 8M 4 brightness werecorrelatedwith theluminositydifferencein velocity dispersion.Thecore radiusandeffectivesurface averaged 0.5magbrighterthanellipticalgalaxiesatthesame elliptical galaxies(FaberandJackson1976;Sargentetal.1977 ; luminosity oftheBCMgalaxiespoorly.The several tantalizingresults.OnewasthattheLocarelation for Schechter andGunn1979;1980)predicts the The AstrophysicalJournal,291:8-31,1985April1 (Peebles 1968;GellerandPeebles1976),orareproducedby evolution. WhethercD’sarejustthelargestellipticalgalaxies may provideimportantcluestounderstandingtheiroriginand for whichOemler(1976,hereafter076)hadpublishedsurface candles incosmology,butfirstitisessentialtounderstand Tremaine andRichstone1977;OstrikerHausman1977, where thecDgalaxiesarefound(Peach1969;Sandage1976; © 1985.TheAmericanAstronomicalSociety.Allrightsreserved.PrintedinU.S.A. metric observationsareusedtoincreasethenumberofBCM dispersions foreightbrightestclustermember(BCM)galaxies their photometricpropertiesandthevariationofthoseproper- the universe,therearestrongreasonstousethemasstandard galaxies. Sincethesegalaxiesareamongthebrightestobjectsin should leaveasignatureinthepresentpropertiesofcD hereafter OH;HausmanandOstriker1978,HO), special dynamicalprocessesthataltergalaxiesinclusters to 31. galaxies withbothvelocitydispersionsandsurfacephotometry brightness profiles.Inthispapernewspectroscopicandphoto- presented inPaperI(MalumuthandKirshner1981)velocity ties (GunnandOke1975;Sandage,Kristian,Westphal the AssociationofUniversitiesfor Research inAstronomy,Inc.,undercon- tract withtheNationalScienceFoundation. 1976). Togainadeeperunderstandingofthesegalaxies,we 2 1 Although thesampleinPaperIwasquitesmall,therewere The dynamicalandphotometricpropertiesofcDgalaxies AlfredP.SloanFoundation ResearchFellow. Guestobservers,KittPeakNational Observatory,whichisoperatedby 4-1 cluster members(BCMs)aresubstantiallybrighterthanpredictedfromtheirvelocitydispersionsandthe improved setofdataforinvestigatingthebrightestgalaxiesingalaxyclusters.Wefindthat luminosities aretheflattest.AnotheristhatVbandmass-to-lightratiosforBCMgalaxiesinthissample ed bysimplemergermodelsisthatthesurfacebrightnessprofilesofgalaxieswhichhavelargestexcess to thespreadofMatgivena,butshowthatobserveddistributionluminosityexcessdoesnotcorre- average 1.22magbrighterthanEgalaxies.Weconsiderthepossibilitythatthismightbeaselectioneffectdue Loca relationforellipticalgalaxies.Intherangeofvelocitydispersionfrom193to346kms,BCMs the McGraw-HillObservatory1.3mandKPNONo.10.9telescopes.Theresultsprovideagreatly and thelowestsurfacebrightnesses,aspredictedbyhomologousmergermodels.Oneresultthatisnotpredict- We notethatourdatashowtheBCMswithlargestexcessluminosityhaveeffectiveradii spond toasimplemodelofselectionunlesstheellipticalgalaxysamplesuffersMalmquistbias0.4mag. average 9.0±0.8,ascomparedwith6.50.7forourellipticalgalaxies. Subject headings:galaxiesclustering—internalmotionsphotometry © American Astronomical Society • Provided by the NASA Astrophysics Data System Velocity dispersionsfor46galaxiesandCCDsurfacephotometry27havebeenobtainedusing I. INTRODUCTION AND VELOCITYDISPERSIONSOFBRIGHTESTCLUSTERMEMBERS DYNAMICS OFLUMINOUSGALAXIES.II.SURFACEPHOTOMETRY 1,2 Eliot M.MalumuthandRobertP.Kirshner Received 1983September9;accepted]984October8 Department ofAstronomy,UniversityMichigan ABSTRACT measure oftheamountevolutionthatagivenBCMhas determine velocitydispersions.WealsoobtainedCCD improves thatsituationbysubstantiallyextendingthesample. formation. However,thesmallaveragevalueofresidual consistent withthedynamicalevolutionpictureofcDgalaxy persion doesnotchange.Theluminosityresidualwouldbea models ofOHandHO.Inthesemodels,eachmergerresultsin (1958) richclusters,13BCMs in“poorclusters”(Morgan, photometry tomeasurethesurfacebrightnessprofilesof 27 We obtainedspectraof46BCMgalaxiesandanalyzedthem undergone. ThecorrelationofRandIwiththatresidualis a brightergalaxythantheinitialgalaxy,butvelocitydis- the contrastingideapresentinsimplehomologousmerger and Peebles1976),theyareingoodaccordwithpredictionsof nosity functionastheellipticalgalaxies(Peebles1968;Geller the ideathatBCMgalaxiesaredrawnfromsamelumi- We obtainedvelocitydispersions for28BCMgalaxiesinAbell properties ofcDgalaxiesto those ofbrightellipticalgalaxies. of theresultsPaperI. BCM galaxies.Thesenewdataarethenexaminedinthe light using theFourierquotientmethod(Sargentetal1977) to and thesmallnumberofgalaxiesweakenresult.Thispaper Kayser, andWhite 1975,hereafterMKW; Albert, White,and larger andhadlowersurfacebrightnessthanthosewithsmall residuals. discuss thepositionsofBCMgalaxiesinL-aplane in sense thatgalaxieswithlargepositiveresidualswerephysically summarized in§V. terms ofthemergerhypothesiscDformation.Theresults are the surfacephotometrymeasurementsin§III.InIV we ce While theseresultsarenotbythemselvesinconsistentwith Our aimistocomparethe dynamicalandphotometric We presentthevelocitydispersionmeasurementsin§II,and II. VELOCITYDISPERSIONS a) TheSample 1985ApJ. ..291 .... 8M photometry thatextendedtofaintsurfacebrightnesslimitswas groups orclusters.Eightofthesegalaxieswerechosenbecause available (076).TherestoftheBCMgalaxieswerechosenon Morgan 1977,hereafterAWM)andfiveBCMgalaxiesinother fication schemeproceedsthroughtypesI-II,II,II-III,andIII dominant cDgalaxy(BautzandMorgan1970).Theclassi- the Bautz-MorgantypeIclusterwasthatitcontainedasingle the basisofBautz-Morgantype,sinceoriginaldefinition in orderofdecreasingdominancetheBCMgalaxy.Most would havetakenprohibitivelylongtoobservewiththe emphasizes low-redshiftgalaxies,sincemoredistantgalaxies type I-IIclusters(21ofthe28Abellclusters).Thesamplealso the BCMgalaxiesinthissampleareBautz-MorgantypeIor galaxies haveredshiftslessthanz=0.08,withameanof McGraw-Hill Observatory1.3mtelescope.Alloftheobserved © American Astronomical Society NGC NGC 6086 NGC 6166 NGC 7720SJ NGC 7720N1 NGC 3090 NGC 7768 NGC 5400 NGC 4073 NGC 2804 NGC 5629 NGC 4213 NGC 741 NGC 6269 NGC 4486 NGC 3158 NGC 1129 IC 4062 NGC 7619 NGC 4889 NGC 4486 NGC 4486 NGC 1600 Galaxy 2831 3 a b b b b b b b b b b b a a b 3 3 3 3 a a A119 A76 A496 A401 A261 A151 A150 A957 A779 A754 A505 A194 A994 A2147 A2107 A2052 A1775 A1631 A1177 A2199 A2162 A2366 A2457 A2589 A2670 A2666 A2634 AWM 3 AWM 2 AWM T MKW 4 MKW 2 MKW l AWM 6 AWM 5 AWM 4 MKW 2s MKW ls MKW 5 NGC 3158 NGC 741 AWM 7 Coma Virgo Virgo Virgo NGC 1600 Pegasus I Cluster DYNAMICS OFLUMINOUSGALAXIES Bautz-Morgan II-III II-III Type II- I I II- I II-III II- I I-II I-II I- I I I-II I-II I- I I I-II I- I I-II I-II I-II III II II III III III II II I I II I I II II I I I I I I I I I I I I I I I I Velocity Dispersions BCM Galaxies Provided bythe NASA Astrophysics Data System TABLE l Richness -2 -1 -1 -2 -2 -1 -1 -3 -3 -1 -2 0 0 3 0 0 0 0 0 2 1 1 1 1 z =0.035.Galaxieswithmultiplenucleiweregenerally ple nucleusgalaxiesA2199andA2634wereobservedbecause the nucleiisdynamicalcenterofcDgalaxy.Themulti- avoided becauseofthepossibilityconfusionoverwhich elliptical galaxies,butsomeofwhichmaybeSOgalaxies.These largest nucleuswastakentobethecenterofcDgalaxy.In they hadsurfacephotometryfrom076.Inbothcasesthe was thelargeroftwo.Sincedifferenceinredshift the caseofA2634bothnucleiwereobserved:southernone northern oneisjustasmallgalaxyinthelineofsight. between thetwonucleiis990kms“,itseemslikelythat ity dispersionarelistedinTable1,alongwiththeBautz- various nearbyclusters.Allofthegalaxiesobservedforveloc- galaxies aretypicallysecondorlowerrankedmembersof Thirty-one othergalaxieswereobserved,mostofwhichare 5 Counts (10) 236 ±24 408 ±43 408 ±33 245 ±35 306 +31 246 ±23 330 +31 254 ±27 367 ±35 353 ±32 438 ±54 249 ±26 279 ±16 311+29 372 ±26 439 ±46 330 ±28 477 ±41 306 ±42 321 ±35 342 ±26 416 ±30 426 ±42 215 ±25 391 ±35 346 ±27 206 ±19 243 ±23 255 ±22 363 ±30 397 ±29 197 ±36 364 ±52 247 ±28 206 ±19 301 ±29 411+43 278 ±40 428 ±31 228 ±24 328 ±29 390 ±30 363 ±28 345 ±28 335 ±25 327 ±27 302 ±33 318 ±46 336 ±23 0.0451 0.0383 0.0532 0.0599 0.0744 0.0467 0.0181 0.0539 0.0540 0.0325 0.0443 0.0234 0.0319 0.0390 0.0357 0.0425 0.0348 0.0689 0.0128 0.0321 0.0542 0.0309 0.0420 0.0595 0.0278 0.0309 0.0276 0.0383 0.0202 0.0776 0.0302 0.0168 0.0253 0.0192 0.0223 0.0271 0.0325 0.0152 0.0182 0.0357 0.0356 0.0045 0.0038 0.0224 0.0154 0.0189 0.0214 0.0040 0.0133 1980 Sep 1980 Sep 1979 Nov 1979 Nov 1980 Sep 1980 Sep 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 May 1980 Feb 1979 Nov 1979 Nov 1980 Feb 1979 May 1980 Sep 1979 May 1980 Sep 1979 May 1979 May 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 May 1979 Nov 1979 Nov 1979 May 1979 May 1979 May 1979 May 1981 Apr 1979 Nov 1979 May 1980 Sep 1979 May 1979 Nov 1979 Nov 1979 Nov 1981 Apr 1981 Feb 1979 Nov 1980 Feb Run 9 ; Maydataanda4"x10"slitwasusedfortheother runs;
I about5Â.Ingenerala2"8x10"slitwasusedforthe 1979 1985ApJ. ..291 .... 8M 5 -1 5 10 sample ofcDgalaxieswherewehavespatiallyresolvedvelocity counts obtainedforeachgalaxy islistedinTable1.Theinte- each galaxy,with4x10counts inmostcases.Thenumberof wavelength was5150Aforthe 1979Mayrunand4900Âfor channel, andafullwidthathalf-maximumresolution of unless otherwiseindicated. aligned withthegalaxy’sminor axisinallcases.Thecentral introduced bythevariationinprojectedslitsize.The was dispersion profiles,isthatnosignificantsystematiceffect is runs werepreviouslyreportedinPaperI.Anintensified telescope oftheMcGraw-HillObservatoryinsixruns:1979 Bautz-Morgan typesarefromLeirandvandenBergh(1977) gration timesvariedfrom10 minutesforNGC4472to3.5 all otherruns.Aminimumof 2x10countswasobtainedfor radius arecertainlypossible,ourevidence,basedonasmall tical galaxies.Whilevariationsofvelocitydispersion with however, thesmallerslitwasusedforsomeoffainterellip- obtain datain2048channelsatadispersionof1.1 Â Reticon scannerwithevent-centeringelectronicswasused to, February, and1981April.Someoftheresultsfrom1979 May, 1979November,1980February,September,1981 Morgan typeandclusterrichnessforeachcluster.The May, 1979November,1980February,andSeptember The spectroscopicobservationswereobtainedwiththe1.3m © American Astronomical Society • Provided by the NASA Astrophysics Data System b) ObservationsandAnalysis NGC 636 NGC 533 NGC 4564 NGC 4467 NGC 4458 NGC 4374 NGC 2693 NGC 2629 NGC 1889 NGC 1521 NGC 1426 NGC 1316 NGC 1278 NGC 1273 NGC 1272 NGC 1209 NGC 1052 NGC 7626 NGC 4874 NGC 4692 NGC 4649 NGC 4473 NGC 4472 NGC 4472 NGC 4406 NGC 2768 NGC 2672 NGC 1700 NGC 1400 IC 708 NGC 7626 NGC 6703 1 ’ Bautz-MorgantypeandrichnessfromBahcall1980. Bautz-MorgantypeandrichnessfromSandageHardy1973. Galaxy 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 a a Coma Coma Virgo Virgo Virgo Virgo Virgo Virgo Virgo Virgo Virgo A1314 Fornax Perseus Perseus Perseus Pegasus I Pegasus I Cluster Bautz-Morgan MALUMUTH ANDKIRSHNER II-III II-III II-III Type III III III III III III III III III III II II II II TABLE 1—Continued Elliptical Galaxies Richness -1 -1 -1 -1 6 (W æ100kms)anddriftinthewavelengths,D,weremade cos bsin/.Theerrorsintheredshiftswereapproximately 100 (A194, A957,A2107,andA2199).Thevelocitydispersion and essentially identicalwiththatofSargentetal(1977)wasused erroneous (butsmall)correction removed. Table 1forthosegalaxiesreported inPaperIhavehadthis the velocitydispersionisdetermined, thecorrectionfor1+z sions. Sincethespectraarebinned inequalstepslogvbefore stretching ofthespectrawasappliedtovelocitydisper- km sforallofthegalaxies.InPaperIacorrection1 -bz shifts havebeencorrectedforgalacticrotationusingAV= 300 redshifts aregivenincolumns(6)and(7)ofTable1.The red- km s;however,itwasconsiderablylargerinafewcases a galaxyobservation.Thedriftwastypicallysmallerthan 35 drift wasdeterminedbytakingcomparisonspectraeveryhour as outlinedbyWhitmore,Kirshner,andSchechter(1979). The velocity dispersiona.Correctionsfortheresolutionwidth to obtaintheredshiftz,line-strengthparameter7,and to 46kmsfrom41505680Â.AFourierquotientmethod analysis. Thestarsusuallyhad4x10countsintheirspectra. III, andwereusedastemplatesintheFourierquotient setting asforthegalaxies.ThesestarsweretypicallyG8III-K5 stars wereobtainedoneachrun,withthesameinstrumental hours fortheBCMgalaxyinA401.Severallate-typegiant stretching isinherentinthe methodandthecorrectionin or soandcomparingthewavelengthsobtainedbefore after Paper Ishouldnothavebeen applied.Thevaluesofolistedin The datawerebinnedinstepslogvwhichcorresponded 5 Counts (10) 324 ±25 244 +19 207 +23 297 +26 296 ±27 245 ±28 259 ±20 281 ±21 284 ±35 230 ±27 203 ±12 343 ±20 299 ±21 332 ±24 303 ±31 267 ±20 250 ±29 223 ±23 344 ±23 283 +25 274 ±26 245 ±20 363 ±30 310 +23 311 ±29 192 ±33 174 ±17 102 ±17 176 +21 153 ±22 159 ±19 90 +20 -0.0012 0.0135 0.0044 0.0205 0.0182 0.0131 0.0088 0.0052 0.0064 0.0189 0.0031 0.0027 0.0047 0.0021 0.0030 0.0049 0.0163 0.0140 0.0128 0.0079 0.0126 0.0017 0.0058 0.0317 0.0123 0.0119 0.0090 0.0241 0.0267 0.0034 0.0037 0.0071 1980 Feb 1979 Nov 1980 Sep 1981 Apr 1979 May 1981 Apr 1981 Apr 1070 Nov 1979 Nov 1980 Sep 1980 Sep 1980 Sep 1980 Feb 1980 Feb 1980 Sep 1979 Nov 1981 Feb 1979 May 1979 May 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1979 Nov 1980 Sep 1979 Nov 1980 Feb 1981 Feb 1981 Apr 1980 Feb 1979 May 1980 Sep Run Vol. 291 1985ApJ. ..291 .... 8M _1 _1 _1 -1 -1 _1 Tonry 1980,hereafterT80;Davies1981,D81;and by theseauthors.ThebrightestmemberofA401hasamea- No. 1,1985 (D ä130kms).Wehavethereforeadoptedaweightedmean measured here.ThevelocitydispersioninNGC6166(the good agreementwiththevelocitydispersionof367kms the sodiumDline.However,theyestimatethatrestof sured velocitydispersionof480±120kmsbyFBDfrom Only fourBCMgalaxiesinAbellclustershavebeenmeasured Faber, Burstein,andDressier1977,hereafterFBD)inTable2. hereafter WK;Schechter1980,S80;Sargentetal. those ofsevenotherauthors(WhitmoreandKirshner1981, is 380kms. poorest determinationsandthedriftwasunusuallylarge the 350kmsdeterminedbyFJ;however,itwasoneofour spectrum indicatesavalueof350kms.Thisestimateisin to theFJvalue.TheadoptedvelocitydispersionofNGC6166 BCM galaxyinA2199)determinedhereismuchlargerthan imately 6%largerthantheothers.Sinceinternalerrorsare persions agreequitewellwithWKandS80areapprox- of ourmeasurementandthatFJ,withdoubleweightgiven authors issatisfactory. typically about10%,theoverallagreementwiththeseother sample ofellipticalgalaxiesobservedhere.Ingeneralourdis- 1977, hereafterSSBS;FaberandJackson1976,FJ; galaxies inAbellclustersandeightBCMMKWor We compareourvelocitydispersionmeasurementswith There isconsiderableoverlapwiththeseauthorsinthe Direct CCDimageswereobtainedforasampleof19BCM 1976; T80=Tonry1980;D81Davies 1981;FBD=Faber,Burstein,andDressier1977. © American Astronomical Society • Provided by the NASA Astrophysics Data System NGC 741.. NGC 636.. NGC 533.. A779 A401 NGC 1400. NGC 1052. NGC 2768. NGC 1700. NGC 1600. NGC 1426. NGC 4486. NGC 4473. NGC 4472. NGC 4467. NGC 4406. NGC 4374. NGC 3158. NGC 4649. NGC 4564. Average factors NGC 7626. NGC 7619. NGC 6166. NGC 4889. a c b Otherauthors:WK=Whitmoreand Kirshner1981;S80=Schechter1980;SSBSSargentetal.1977; FJ =FaberandJackson AveragesofthevaluesinTable1. ValueexcludingthesodiumDline. c) ComparisonwithOtherAuthors Galaxy III. SURFACEPHOTOMETRY a) TheSample 284 + 372 + 367 ±35 267 + 250 + 345 + 207 ± 439 ± 428 ± 244 ± 299 + 363 ± 245 + 203 + 352 ± 390 ± 292 + 324 + 343 + 174 ± 336 ± 153 ± 192 ± 102 + c c c c c 26 28 23 20 28 22 29 35 33 46 40 25 21 30 25 20 25 23 31 17 12 17 19 DYNAMICS OFLUMINOUSGALAXIES 283 ±18 282 +30 300 +23 358 +29 WK 1.01 3 Comparison withOtherAuthors 273 ±25 212 ±19 231 ±12 298 ±18 267 ±38 383 ±33 330 +37 176 ±14 0.99 S80 TABLE 2 318 +35 263 +17 187 ±16 151 ±8 cluster BCMs.Thevelocitydispersionofa17thAbell AWM poorclusters.ThesurfacephotometrystandardNGC photometry of076andTRgivesusasample31BCM the 19AbellclusterBCMgalaxies,andalleightofpoor published surfacebrightnessprofilestofaintlimits(076).In Table 3.TheCCDcamerausedontheMcGraw-HillObserva- 0.9 mtelescopetoobtainimagesofthe28galaxieslistedin exposure timesandthetelescopeused. galaxies withbothsurfacephotometryandvelocitydisper- BCM (inA2029)ispublishedbyDressier(1979).Includingthe published profilesforfiveofthepoorclusterBCMgalaxiesin addition, ThuanandRomanishin(1981,hereafterTR)have Of theBCMgalaxiesinAbellclusters,threehavepreviously cloudy, mostofthemwerephotometric.Surfacephotometryin ton University.Thesedatawereobtainedinthreeruns,1981 tory telescopewasdevelopedbyDr.DonaldYorkandPrince- this sample.Wehavedeterminedvelocitydispersionsfor16of 3379 (deVaucouleursandCapaccioli1979)wasalsoobserved. partly cloudyweatherisreasonableaslongtheexposure moonless skies.Althoughsomeofthenightswerepartly December and1982MayatMcGraw-HillObservatory tometry inTable3alongwiththenumberofexposures, sions. Welistallofthegalaxiesobservedforsurfacepho- conditions. Bygoodfortune,thelastnightofeachrunwas However, theabsolutecalibrationwillnotbegoodundersuch the field,sinceentirefieldwillbeobscuredinsameway. time islongcomparedwiththeittakesforacloudtocross 1.3 mtelescopeandtheKittPeakNationalObservatoryNo.1 1982 JuneatKPNO.Mostofthegalaxieswereobservedwith SSBS 1.06 CCD cameraswereusedontheMcGraw-HillObservatory 265 ±19 285 ±15 400 +40 295 ±6 315 +28 350 ±35 360 ±36 <150 1.07 FJ b) ObservationsandAnalysis 268 ±22 301 +11 267 ± 218 ±23 241 ±14 270 +16 301 +14 411 ±20 228 +7 319 ± 372 ±20 352 ±23 285 +17 316 +830820 222 ±23 285 ±20 341 +13 348 ±12 177 ±22 T80 1.06 257 +12 280 ±14 D81 1.05 b 1 350 Í480 + FBD 120 11 1985ApJ. ..291 .... 8M -1 -1 12 MALUMUTHANDKIRSHNERVol.291 photometric, soweobtainedashortexposureofeachthe digital convertorunit(ADU),the1982Maydataat40.0elec- bration forthosegalaxies. ditions. Theseshortexposureswereusedfortheabsolutecali- galaxies whichhadbeenobservedundernonphotometriccon- December dataweredigitizedat13.0electronsperanalogto trons perADU,andtheKPNO(1982June)dataat14.8elec- long exposure.Thisresultedinthesaturationofanalogto the maximumsignalinlowsurfacebrightnessregionsa trons perADU.Thechoicesofdigitizationweremadetoget f/7.5, whichgaveafieldof5'.6x3'.5fortheMcGraw-Hill digital conversionnearthecentersofsomegalaxies.A tion nearthecenterinthosecases.Bothtelescopeswereused at short exposurewasusedtodeterminetheluminositydistribu- observations and7'.3x4'6fortheKPNOin the trons foreachcamera. KPNO observations.Thereadoutnoisewasabout75 elec- frames wereobtainedatbothtelescopes.Domeflat and with aF-likefilter.Thefilter usedinthe1981Decemberrun bias frameswerealsoobtainedatKPNO.Standardstars with McGraw-Hill observationsand0.85arcsecpixelfor the 512 x320pixels.Thescalewas0.65arcsecpixelfor the has apeaktransmissionatabout 5300Âandessentiallyno videocamera/CCD standardfields.Allimageswereobtained absolute calibration.TheseweretypicallyinKittPeak galaxy-like colorswereobtainedeachnightofrun for transmission shortof4850Â or longwardof6000Â.Thefilter has apeaktransmissionatabout 5400Âanddropsessentially used intheotherrunswas KPNONo.18F-filter,which to zeroat4750and7000Â. RCA CCDchipswereusedinbothcameras.The1981 Along withtheimagesofgalaxy,darkframesandskyflat © American Astronomical Society • Provided by the NASA Astrophysics Data System NGC 6086A21622 NGC 5400MKW52 NGC 7768A26663 NGC 4213AWM2 NGC 2804AWM12 NGC 6269AWM52 NGC 5629AWM31 NGC 3379M96group2 NGC 1129AWM73 IC 4062AWM61 Galaxy ClusterExposures(minutes)Telescope A4012 A1177 2 A994 2 A505 2 A496 3 A150 2 A1904 2 A1631 2 A2107 2 A2052 1 A2029 2 A2457 2 A2366 2 A2147 1 A2124 2 A2670 1 A2589 4 AWM 41 Surface PhotometryObservations Number ofExposureTime TABLE 3 was thenflattenedbydividingitanaverageskyflatwhich read areaof20rows,anddark-subtractedusinganaverage ite skyframe:theaverageofallframescleanedstars. in theKPNOdata.Thiswasdealtwithbyformingacompos- ference fringescausedbythe5577Ânight-skylinewerepresent had beencleanedofstarsandgalaxies.TheKPNOdatawere all ofthedarkframesobtainedduringrun.Thedataframe (IPPS) Comtaldisplayunitwithveryhighcontrast.Asecond This compositeskywasmultipliedbyaconstantandthen an averageofthedomeflatstakenonsamenight.Inter- the observation.Eachframewasthenflattenedbydividing bias-subtracted usingthebiasframesobtainedonnightof made bylookingattheresidualfringes.Thiswasnecessary played ontheKPNOinteractivepictureprocessingsystem fringes couldnolongerbeseenonthedisplayunit.Atthat time continuum. Thisprocesswascontinueduntiltheresidual because thenight-skylinevariesinstrengthrelativeto the guess oftheconstantneededtomultiplyskyframeby was subtracted fromthedataframe.Theresultingframewasdis- were replacedwithzeros.Stars andgalaxiesinthefieldwere gradient intheskyremoved, badcolumns,rows,andpixels was subtractedfromthedataframeandaveragevalue which hadnobrightobjectsnearthecornersofframe, so the residualfringeamplitudewassmallerthan1%ofsky. removed byreplacingwithzeros allofthepixelswithincircles cally l%-2%ofthesky. that wecouldmeasuretheskyinallfourcorners.Thisplane across theframe.Thegradient measuredinthiswaywastypi- added back.Thisremovesanylarge-scalegradientinthe sky 30 MGH1.3m The McGraw-Hilldatawerebias-subtractedusinganover- Once theframeswereflattened, thefringesremoved,and A planewasfittedtotheskybackgroundforthosegalaxies 5 30MGH1.3m 5 1530MGH1.3m 30 MGH1.3m 30 MGH1.3m 15 60MGH1.3m 15 30MGH1.3m 15 30MGH1.3m 30 MGH1.3m 15 50MGH1.3m 10 60MGH1.3m 2 60KPNONo.10.9m 5 60KPNONo.10.9m 5 60KPNONo.10.9m 5 60KPNONo.10.9m 5 60KPNONo.10.9m 5 30KPNONo.10.9m 5 40KPNONo.10.9m 5 60KPNONo.10.9m 5 60KPNONo.10.9m 5 60KPNONo.10.9m 2 30MGH1.3m 5 60KPNONo.10.9m 30 MGH1.3m 30 MGH1.3m 60 MGH1.3m 5 KPNONo.10.9m 5 KPNONo.10.9m 5 KPNONo.10.9m 1985ApJ. ..291 .... 8M -2 -2 -2 1/2 No. 1,1985DYNAMICSOFLUMINOUSGALAXIES13 were about1%ofthesky.Thiscleaningstarsandgalaxies method ofKent(1983)asadaptedbyHegyi,Gudehus,and of approximatelytwicetheradiuscontourwherethey ignored) at1pixelintervalsinthesemimajoraxis,using of theframewithdata. and ofthebadpixels,rows,columnsleftabout60%-70% Sharkin (1983).ThismethodissimilartothatofYoungetal. major axisandwassmoothedbyfittingastraightlinetothe ellipse, thepositionangle,andellipticitywerethen ellipticity wereobtainedforeachisophotedowntoasurface (1979). Thecenteroftheellipse,positionangle,and cases thedatawerebestdescribedbyahigher(upto5th)order fits toeachisophotehadalargeamountofscatter.These may beacluetothetrueshapeofthisgalaxy.Thevalues isophotes inthisgalaxychangesbyabout5"fromthecenterto the centerpositionclearlyvariedasafunctionofsemi- brightness ofapproximately25magarcsec.Thecenterthe data. chosen tobestrepresentthetrendinunsmootheddata.A different rangesinradii.Theorderofthepolynomialwas quantities weresmoothedusingoneormorepolynomialsover position angleandellipticitydeterminedfromtheindividual the edgeofgalaxy.Thisvariationappearstoberealand unsmoothed valuesofthecenterposition.The as theaverageofcentersallisophotes.ForA2666 smoothed withradius.Inallbutonecasethecenterwasfixed obtained whichwasagoodrepresentationoftheunsmoothed polynomial. Thisprocesscontinueduntilasmoothcurvewas second-order polynomialwasusedinmanycases,andafew mag perairmass. ellipticity, andpositionanglesasthelastsmoothedone.The into magarcsecusingthecalibrationstarsobserved photes wereaveragedinroughlylogarithmicbinsandchanged areas nearthecornersofframe,andthensubtracted.Iso- the datawouldallowbyassumingcontoursofsamecenter, the isophotes.Beyondthat,profilewasextendedasfar semimajor axis.Theseaveragesarethesurfacebrightnessesof smoothed quantitieswereaveragedatintervalsof1pixelinthe exposure wasobtained,andtheresultshavebeenaveraged exposure exclusivelyfarfromthecenter,andanaverageof the As mentionedbefore,theinnerpartsofmanylongexpo- same nightasthegalaxy.Theatmosphericextinctionwas0.20 sky levelwasdeterminedfromtheaverageofpixelvaluesin two exposuresinbetween.Insomecasesmorethanone long also obtained.Inthosecasesacompositeprofilewasproduced sures weresaturated,soinmostcasesashortexposure was arcsec), versusthelogofgeometricmeansemi- have spectralenergydistributions likethoseofEgalaxies. distribution ofthegalaxy.The BCMgalaxieswereassumedto (1976) arelistedinTable4.These K-correctionsincludeonly galaxies correctedforgalactic absorptionusingthemodelof the 1+zstretchingofspectrum andthespectralenergy guider ontheKittPeakNo.10.9mtelescope.Inthosecases and AWM4werelostasaresultofproblemwiththeauto- together atallradii.ThelongexposuresofA2147,AWM 3, using theshortexposureexclusivelynearcenter, long Sandage (1973)andK-corrected usingthetablesofPence only ashortexposurewasobtained. major andsemiminoraxes[logr=log(ah)]wasproduced Ellipses werethenfittedtotheremainingdata(zeros The valuesofeachpixelalongtheellipsesdefinedby In thiswayatableofsurfacebrightness,ii(inmag The finalcompositesurfacebrightnessprofilesoftheBCM v © American Astronomical Society • Provided by the NASA Astrophysics Data System - -2 4 -1 -2 -2 Where thesurfacebrightnessisgiveninunitsofmagarcsec, with eachother,unitsofLpcareused,assumingH=50 when thesurfacebrightnessesofgalaxiesarecompared no correctionfor(1+z)dimminghasbeenmade.However, The averageaxialratio,b/a,is0.7±0.03atasurfacebright- brightness tothelocalrestframeofgalaxy. km sMpcandq=0.Theseunitscorrectthesurface clusters intheirsample.However,whentheyexcludedthe ness of24magarcsecforthesegalaxies.Leirandvanden Bergh (1977)foundasimilarvaluefortheBautz-MorgantypeI more distantclusters,theyfoundasmallervalue(flatter elliptical withradius.Sinceanearbygalaxycoversmorearea galaxies). TheBCMgalaxiesinBautz-MorgantypesII-IIIand 3379 isanearbygalaxyandlargerthanthe5'6x3'.5fieldof why LeirandvandenBergh(1977)foundthenearerBCM down toafaintisophoteonnearbygalaxy.Thismayexplain galaxies). Mostofthegalaxiesinthissamplebecomemore as flat({b/a}=0.83foralloftheBautz-MorgantypeHIBCM III clustersinLeirandvandenBergh’s(1977)samplewerenot galaxies tobeflatteronaveragethantheirentiresample. on aphotographicplatethandistantgalaxy,itiseasiertosee comparison ofthisgalaxydoessuggestthattherelativepho- NGC 3379(deVaucouleursandCapaccioli1979)was The agreementisbetterthan0.08mag peaktobeyondthat. Vaucouleurs andCapaccioli(1979)inFigure1.Thezero-point tory. OurprofileofNGC3379iscomparedwiththatde published surfacebrightnessprofileby076orTRwere of 0.85mag.Atradiilessthan1"thedifference islargebecauseofseeingeffects. profile minusours.Thezero-pointshift wasarbitraryandrepresentsa.B—V Vaucouleurs andCapaccioli(1979). AM isthedeVaucouleursandCapaccioli fainter thanthestandardprofileincentral1"0becauseof last pointisnotatzerodifferenceinFigure1,sincetheaverage dimension. Wechoseaskyvaluesothatthelastpointin radius of100",theedgeframeinshort the CCD.Thesurfacebrightnessis22.7magarcsecata shift wasarbitraryandrepresentsa£—Fof0.85mag.NGC observed inthe1981DecemberrunatMcGraw-HillObserva- observed. Inaddition,thesurfacephotometrystandardgalaxy 0 throughout. This,ofcourse,doesnottellushowaccuratethe shift wasdeterminedaftertheskyvalueset.Ourprofileis 0 absolute photometryortheskydeterminationsare,but seeing, butafterthattheagreementisbetterthan0.08mag Figure 1wasinfairagreementwiththestandardprofile.The The positionangleandellipticitiesarealsolistedinTable4. During eachrun,oneormoregalaxieswithapreviously Fig. 1.—Comparisonofourphotometry ofNGC3379withthatde <-0.2 - + 0,1 -0.4- -0.7 I^^^ -J ^1- -0.6 -+ -0.5- + -0.3 - .0.1 I+^ + 0.0 ,+4-+.,4--^■ '¿1+ 0.2 - 0.3 - -0.5 0.00.51.01.5 2.02.5 c) ComparisonwithOtherAuthors LOG RADIUS(SEC) NGC 3379 1985ApJ. ..291 .... 8M i arcse> Log r -0.06 -0.32 Log r . 78 . 68 . 84 . 01 . 89 . S6 . 65 . 90 . 01 . 95 . 81 . 09 . 54 . 47 . 65 . 79 . 07 . 31 6 3 73 9 6 20 24 36 3 2 2 8 4 1 5 1 4 6 06 60 76 70 1 5 85 24 20 1 5 O 1 60 38 26 73 70 9 7 9 1 85 26 6 2 5 2 4 6 4 1 3 6 72 57 8 2 77 6 7 9 2 87 12 FWHM ofPSF2.3 FWHM ofPSF2.2 20 75 20 5 20 15 2 1.58 2 140 22 62 2 47 19 68 23 16 2 98 2 2.81 19 96 19 79 23.50 23 32 23 65 24 23 2 405 23 83 2 467 24 46 25 45 25 31 25 08 24 85 26 73 26 53 26 48 2 6.32 25 95 25 75 27.52 26 49 2 64 28.04 20.91 20 69 20 52 20.34 20.12 2 93 22 69 2 17 2 1.91 2 1.70 2 1 2 1 2 371 23 17 22 44 16.33 © American Astronomical Society • 25.41 24 35 2 408 2 3.44 18.46 25 91 2 497 24 57 27 98 27 58 26 .72 26 30 19.89 19.62 19.33 A150 4 6 1 6 1 32 1 35 1 34 1 3 1 35 1 79 1 72 1 67 1 63 1 6 1 69 1 7 1 75 1 75 1 75 1 75 1 75 1 75 1 75 175 1 76 1 75 1 76 176 1 76 1 76 176 1 76 1 76 1 76 1 76 1 76 1 76 1 76 1 76 1 76 1 76 1 33 1 33 1 33 1 33 150 1 48 1 39 1 54 1 54 1 54 1 53 1 52 1 52 1 52 1 5 1 50 1 50 150 1 52 1 58 1 56 1 55 154 1 5 1 63 1 62 1 60 1 59 1 57 1 70 1 67 1 65 1 74 1 72 4 4 1 . 12 . 08 . 08 . 12 . 16 . 21 . 21 . 24 . 24 . 24 . 24 . 24 . 24 . 24 . 24 . 24 . 24 . 24 . 24 06 06 08 08 07 08 09 . 22 . 19 . O1 . 27 . 25 . 31 . 29 . 37 . 35 . 35 . 35 . 35 1 2 . 35 . 35 . 35 . 35 . 35 25 26 23 24 2 4 24 . 35 24 24 1 6 1 4 1 9 O 1 O 1 0 9 34 35 35 35 35 1 5 35 35 35 35 35 35 3 5 (ar csec> i arcsec Log r - 022 - 037 Log 0 07 0 37 0.25 0 53 0 46 0 70 0.65 0 59 0.9 1 0 86 0.80 0 74 C .95 1 04 1 OO 1.39 1 33 1.28 155 1 50 1 .89 1.84 1.79 1.74 1.69 16 4 1.60 1 44 0 56 0.84 0 74 0.63 0.97 0.91 0.78 0.69 1.03 118 1.07 1 .27 1.23 1.13 1.41 1.36 1.32 1.85 1 .80 1.76 1.66 1.62 1.51 1.46 1.87 1.83 1.71 1.57 3 4 38 26 4 9 1 O 1 9 FWHM ofPSF2.0 FWHM ofPSF2.8 20 87 20.59 20.29 20.08 2 1.26 2 1.08 2 1.57 2 1.41 22.51 22.36 22 22.02 2 185 2 170 2 77 23.58 23 40 2 3.24 2 .93 22.62 19 9 23 76 23.09 24.98 24 93 24.62 24.37 24.01 25.88 25.29 25 10 2 6.01 25.49 20 08 20 48 20 29 2 108 20 85 20.63 2 128 2 1.92 2 1.76 2 1.59 2 1.45 18 63 18.20 22.39 22.25 22.09 19.52 19 21 18 41 23.63 23.40 22 67 22.53 24 47 23 98 23 80 23 16 22 87 19.80 18 91 25.01 24.67 24 59 24.31 24 16 26 14 25 63 25 28 A 4O1 Surface PhotometryProfiles 9 2 92 6 2 72 73 80 55 37 43 45 46 32 34 36 36 35 35 34 35 35 35 35 35 35 3 5 35 35 35 35 35 35 35 35 35 55 55 55 5 55 5 55 5 5 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 Provided bythe NASA Astrophysics Data System TABLE 4 . OO . OO . 40 . 40 . 40 E Logr 20 24 23 22 2 1 40 40 35 32 27 4 0 40 40 40 40 40 40 40 40 40 1 9 40 40 40 09 09 09 09 09 50 4 9 38 28 2 1 50 50 50 50 1 O 1 3 1 2 1 1 O 1 O 1 7 1 5 14 < arcsec> < arcse) -0.35 -0.20 -0.06 -0.23 0.26 0.07 0.39 0.63 0.56 0 49 0.77 0.73 0.68 0.83 0.95 0.89 1 .05 1 .OO 1 20 1.15 1 .09 1.36 1.33 1.28 1.24 2 12 2.07 2.02 1.58 1.53 1.47 1.42 1.63 1 .82 1.77 1.72 1.67 1.92 1.87 1.97 0.59 0.51 0.39 0 22 0.93 0 73 0.67 0.88 0.83 0.78 10 1 1.11 1.06 142 132 1.27 1.22 1 6 1.66 1.61 1.52 1.4 7 1.37 1.56 . 19 .14 . 09 04 7 6 9 95 90 85 8 1 72 29 24 FWHM ofPSF3.0 FWHM ofPSF2.5 2 0.02 2 019 2 05 20.35 20 75 20 63 2 1.09 20.90 2 1.72 2 1.56 2 1 2 1 19.45 19.34 19.28 22.05 2 1.89 19.82 22.62 22.47 2 2.31 22 20 19 62 22.79 23 48 23.22 23.01 23.66 24.23 24 04 23.85 2 41 25.21 24.90 24.62 26.20 25 95 2 5'9 26.46 26 .77 20 77 20.56 20 35 2 016 20 02 2 163 2 117 20 98 2 1.85 2 1.39 23 76 2 34 23 18 22.90 22 69 22 48 22.27 22.06 18.27 24 69 24 09 19 06 18 79 18 49 18.2 I' 25 43 25.29 24 98 24 35 19.28 26 33 25.91 25.57 19.87 19 71 19.51 28 49 27.59 2 7.10 A 49S 40 26 1 47 1 7 1 4 1 40 158 1 58 1 7 1 57 1 73 1 70 1 73 1 6 1 76 1 72 1 75 1 74 1 76 1 79 176 1 76 1 76 1 76 1 76 1 76 1 76 1 76 1 75 175 1 75 1 7.5 1 75 1 75 1 75 1 75 1 75 1 75 175 1 75 1 6 1 6 6 4 6 1 69 6 9 64 53 53 53 5 3 53 5 3 53 52 52 5 1 52 50 50 5 1 5 1 46 4 8 4 9 4 9 4 1 44 45 4 7 48 34 36 38 39 42 34 34 34 34 3 4 . 18 . 05 . 07 . 1O . 08 . 12 . 08 . 16 . 16 . 13 . 12 . 21 . 16 . 19 . 21 . 23 . 24 . 28 . 32 . 32 . 32 . 32 . 32 . 32 . 32 . 32 . 32 . 32 04 03 . 31 . 30 . 32 .32 1 8 28 28 28 28 29 28 32 1 8 32 23 23 22 23 23 23 23 23 23 23 23 23 23 24 23 23 24 24 25 25 25 24 24 24 29 27 27 26 32 32 28 26 32 32 32 t arcsec) < arcsecl Log r -0 36 -0.21 Log r 0 10 0 27 0 49 O 40 O 57 0 98 O .91 0.84 0.78 0 74 0 69 0 63 1 19 114 1 08 1 .03 1.24 1.48 1.43 1.38 1 .33 1.29 1.53 1 .64 1.59 1.69 1.78 1 .73 1.88 1.83 1.93 1.12 1.16 1 .06 1 .OO 1.27 1.21 1 40 1 .36 1.31 1 79 16 5 1.59 1 .54 1.49 1.45 1 74 169 1.83 04 09 99 1 9 1 4 24 57 48 36 72 65 94 83 78 88 1 3 1 7 FWHM ofPSF40 FWHM ofPSF2.4 20 00 20.36 20.18 20.87 20.54 2 1.77 2 1.56 2 1.35 2 109 20 71 22.79 22.61 22.40 22.19 2 1.97 19.46 23.48 23.22 2 2.98 19.40 24 30 24.07 23.76 19.82 19.66 19.55 24.51 24.80 25.51 25 33 25 04 25.98 25.78 26 41 26 24 25.76 27.79 27.28 20 25 2 1.44 20.97 20.62 2 164 2 1.23 22 30 22.03 2 1.80 22.97 22.73 22 53 23.67 23.44 23.19 24 41 24.19 23.98 23.84 19 86 19.45 19.16 19.09 25.84 25 32 25 07 24.58 26 38 2 608 24.86 A 5OS 1 3 132 1 3 105 1 34 133 132 1 33 135 135 134 1 34 1 40 1 39 1 38 1 37 1 36 145 1 44 1 42 1 4 1 5 1 48 1 47 153 1 63 160 1 57 1 7 1 67 172 1 72 1 72 172 172 1 72 1 72 1 72 3 1 26 28 22 4 2 42 29 26 42 42 42 42 42 42 42 42 42 42 42 1 42 42 42 42 42 1 5 1 8 4 7 . 1 . 12 . 1 . 07 . 09 . O1 . 02 . 02 . 03 . 04 . 02 . O1 . 01 . O1 . 02 . 02 . O1 . 02 . 02 . 02 . 02 07 08 09 05 06 05 04 O 1 1 3 0 1 1 3 1 O 1 O 02 02 23 22 20 20 23 23 23 24 24 24 23 23 25 25 27 26 26 25 33 32 3 1 30 29 29 28 27 36 35 34 1 8 1985ApJ. ..291 .... 8M (ar csec» r i rcs©C) Log -0 22 -0 06 Log r -0.26 - O11 0 76 0.57 0 47 0 36 0 21 0.81 0.71 0 64 0 97 0.91 0.86 1 03 1.12 1.08 O 19 0 36 O 73 O 6 O 58 O 49 0 94 0 78 0 8 O 83 1 6 106 1 OO 138 1 30 1 26 1 20 111 1 42 134 2 04 1 58 1 54 150 1 46 2 09 1 67 1 65 1 62 1 73 1 70 1 89 1 83 1 76 1 98 1 94 2 7 22 34 3 1 09 04 4 3 39 9 4 86 82 6 7 4 6 9 72 6 3 5 3 24 7 56 29 1 9 rWHM ofPSP24 FWHM ofPSF2.7 20 28 2 1.22 2 107 20 50 20 09 2 196 2 1 2 1 2 1.36 20 90 20 71 2 3O1 2 83 22 63 2 29 22 12 2 327 2 307 2 46 2 412 : 6 2 “60 2 4 2 451 2 43 19 67 25 35 24 92 2 470 26 29 26 1 25 78 19 90 19 74 26 04 2 7.54 2 736 2 684 26 53 28 15 © American Astronomical Society • 20 35 2 1 2 1 20 93 20 75 20 56 20 12 2 306 2 51 22 28 2 1O 2 19 2 1 2 1 23 5 2 345 2 325 2 2.66 2 68 2 38 2 356 2 396 23 96 2 3.97 2 383 19 15 19 08 24 95 2 46 2 406 2 496 24 73 19.86 2 516 25 46 25 21 25 53 54 77 09 54 29 76 20 20 20 20 20 2 1 20 22 2 1 2 1 2 1 23 22 22 2 3 23 2 4 22 22 23 24 25 25 2 5 22 22 22 22 2 25 2 4 2 25 2 5 17 1 6 1 6 1 7 1 7 1 7 1 3 1 5 1 6 1 6 1 2 1 3 1 4 1 . 21 . 23 . 45 . 51 . 51 . 48 03 09 27 25 30 4 1 39 32 4 6 44 43 36 4 8 4 7 46 1 8 1 6 1 4 1 4 6 5 52 5 1 50 4 8 48 4 8 52 48 4 8 48 30 27 37 35 29 26 25 25 24 20 45 42 39 33 3 1 23 22 2 2 1 2 1 20 2 1 6 9 65 6 1 57 53 4 9 6 66 6 9 70 6 6 6 1 9 1 9 6 6 1 9 < «rcsec) (ar csec) Log -018 -0 33 0.41 0.10 Log r 0.69 0 58 0.51 0.28 0 64 0.95 0.83 0.77 0.73 0.99 0.89 - O - O. 1.33 1.28 1.24 1.19 1.14 1 .09 1 .04 1 38 14 3 O 1.58 1.53 1.63 1.71 1.67 09 04 79 59 9 4 89 84 7 4 6 9 6 4 5 4 9 0 1 06 37 39 2 5 9 3 6 4 9 35 30 20 78 73 5 8 48 43 88 83 99 94 89 84 19 1 5 1 O FWHM ofPSF20 FWHM ofPSF2.4 20.57 2 0.33 20.18 2 1.27 2 1.15 20.76 20.66 2 0.45 2 1.70 2 1.39 2 1.03 20.88 22 51 2 2.34 22 17 22 01 2 186 2 153 24.26 23 81 23 60 23 40 22 95 22 73 27.05 26.71 26 .28 25 76 25.35 24.98 24 76 24.52 2 402 23 19 19.31 19.20 19.98 19.72 19.48 2 136 2 1.09 20 23 22 42 2 2 1. 2 1 20 86 2 068 20 48 23 71 23.30 23 14 23 01 22.84 22.67 2 1 25 54 24.89 24.64 23 90 23.52 25 28 25 14 24.42 24 .25 24 09 18 18.07 18 47 19 94 19.25 18 84 19 61 9 7 55 77 1 8 1 64 1 64 44 36 37 37 39 50 77 28 28 28 28 28 28 34 28 28 28 28 28 2 8 28 28 28 28 28 28 28 28 28 2 8 28 2 8 28 28 28 28 28 1 79 1 79 1 79 1 79 1 78 1 79 1 79 1 76 1 76 1 76 1 77 1 77 1 78 1 78 1 76 1 76 3 1 TABLE 4—Continued 1 4 1 5 1 2 I 3 1 O II 9 0.14 0 28 0 28 0 28 0.27 0.26 0.24 0.21 O .20 0.17 0.18 0.28 0 28 0.28 0.28 0 28 0.28 0.28 0 28 0.28 0.28 0.28 0.28 0.28 0.28 0 28 0.28 0.28 0.28 0 28 0 28 Provided bythe NASA Astrophysics Data System 0.19 0 18 0 18 0.14 0.21 O .20 O 20 0 26 0.25 0 23 0 22 0.30 0.29 0.28 0 27 0 24 0 23 0 32 0.32 0.31 O .30 0.31 0 36 0.33 0 47 0 40 0.38 0 35 0 48 0 48 O 48 0 48 0 44 0 42 03 05 06 00 00 06 08 1 E Logr 15 (ar csec) Log -0.23 -010 0.50 0.86 0 80 0.6 9 0.59 0.37 O .20 0.95 0.89 O 75 -023 -0.07 114 1 .09 1 02 1.81 1.77 1.71 1.64 1 .59 1.55 0.22 . 34 . 29 . 44 . 39 1.31 . O1 . 97 . 90 . 84 1.36 . 24 . 14 . 09 1.93 1.88 1 75 1.70 04 . 39 1 9 . 52 . 61 . 97 . 91 . 87 . 82 04 6 9 76 FWHM ofPSF40 FWHM OfPSF2.0 20.17 2 1 20 96 20 78 20.62 20.46 22 56 22 35 22 .16 2 1 2 1 2 1 2 1.08 2 344 22.99 22 80 2 483 24 55 23 89 23 68 23 43 23.21 25 6 25 07 24 08 27.09 26 90 26.37 26 09 25 30 19.96 19.52 19.34 19.28 28 72 27.75 26.59 19.73 20 97 2 0.22 2 1.26 20 62 23 10 22 49 22 20 2 1.93 2 1.51 23.87 23.66 23.47 23.28 22.92 22.74 2 174 24.57 24.26 24 09 25 .19 24.92 19.73 18.75 18.60 26 58 26 27 25 83 25 62 25 35 19. 18 26.71 26.24 97 78 56 32 1 09 1 3 1 O 1 07 1 35 1 5 1 6 1 4 1 3 1 2 1 1 1 2 1 OO 1 2 1 1 3 1 36 1 2 1 20 1 8 1 4 1 O 1 5 1 4 103 1 4 1 60 154 1 54 1 43 1 47 1 56 1 43 97 89 1 43 1 43 1 43 1 43 89 89 89 89 14 3 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 1 43 99 99 99 9 1 43 1 43 1 43 1 43 1 43 9 . 12 . 06 . 06 . 17 . 13 . 13 . 14 0 6 06 08 0 1 06 06 29 3 5 3 1 28 30 28 26 32 32 25 3 1 32 32 32 32 22 1 5 1 8 1 3 1 7 1 5 OO 06 05 00 09 08 09 09 09 08 09 09 09 09 22 20 24 1 O 1 O 1 2 1 3 1 2 1 4 1 3 1 8 1 6 1 5 1 7 i *rcsec) ( arcse) Log r -0 09 -0 25 Log r 0.51 0.86 0.81 0.61 0.39 0.21 0.96 0 90 0 75 0.69 -O il -0.25 1.50 1 .36 1.31 1 .09 1.03 1.83 1 79 1.76 1.71 1.61 1 55 145 1 .40 1.25 1 .20 1.16 1.93 1.66 1.88 0.37 0.19 0.66 0 58 0.49 0 79 0.73 0.94 0 84 0.86 1.18 1.13 1 .08 1.01 1.33 1.28 1.23 1.51 1.46 1.42 1 .37 1.71 1.66 1.61 1.56 1.98 1.83 179 1 75 1.87 1.93 1.90 FWHM ofPSF26 FWHM ofPSF2.7 2 117 20 92 20.63 24 18 22.65 2 22 2 1.81 2 1.67 2 150 2 1.35 20 29 27 36 26 34 24 96 24 57 23.95 23.60 23 33 23 23.01 2 2.78 22 44 2 OO 28 52 2 780 26 55 25 79 25 47 19.91 19 57 19 42 20.35 20 97 20 72 22 39 22 09 2 1 2 1.47 2 1.25 23 46 23 20 23 01 22.73 2 1 24.39 24.18 23.96 23 75 19.54 19.21 25.40 2 4.66 19.23 26 75 2 586 25 15 2 486 19.95 27 55 26 52 26 14 26 17 28 00 28 76 27.81 68 84 1 69 1 72 1 43 1 4 1 47 1 53 1 56 1 58 1 60 1 63 16 6 1 75 179 1 39 1 38 1 39 1 40 1 4 1 50 1 36 1 40 1 40 1 39 1 38 1 36 1 36 1 38 1 40 1 40 1 40 80 80 8 1 80 80 8 1 8 1 82 82 82 8 1 8 1 8 1 83 83 82 8 1 85 84 84 83 88 87 85 92 9 1 90 88 86 97 9 7 95 9 3 3 0.17 0 17 0.17 0.17 0 14 0.17 0 17 0.17 0.18 0 18 0.18 0.18 0 20 0 19 0 19 0.19 0.18 0.23 0.22 0.21 0 21 0 20 0.24 . 1O . 37 08 0 9 06 06 07 23 22 2 1 20 27 26 26 25 24 32 30 29 27 36 28 1 3 1 2 1 9 1 7 1 4 1 3 1 6 26 36 27 25 39 33 3 1 29 50 49 44 1985ApJ. . .291 . . . .8M (ar csec> ■ rcse) Log r - O09 *0 23 Log r 0 20 O 6& 0 61 O 50 0 39 0 8 0 74 0 86 0 95 0 89 0 45 0 36 0 23 0 6 O 60 0 53 O 82 O 75 0 71 0 89 0 95 102 2 13 2 08 2 03 1 4 1 09 2 18 1 4 140 1 36 13 2 1 27 1 22 1 8 2 3 157 153 148 1 72 1 69 16 5 1 62 178 1 75 1 93 1 87 18 2 1 98 1 OO 1 05 1 35 1 26 1 2 1 6 1 O 1 45 1 40 1 30 02 07 6 7 6 2 5 7 9 7 9 2 87 82 77 7 2 1 6 1 2 FWMM OfPSF23 FWHM ofPSF23 2 054 20 33 20 61 2 137 2 119 2 10 22 58 2 7 2 11 2 1 2 1 2 1 2 351 23.37 23 19 2 305 2 90 2 76 2 4 18 87 2 408 2 381 23 68 19 41 19 04 2 431 24 21 23 95 19 87 2 45 2 439 25 44 2 516 2 496 24 70 26 14 2 570 2 69 26 32 2 769 20 42 20 25 20 07 20 93 20 65 2 118 2 183 2 16 2 1.40 2 24 22 05 2 98 2 78 22 59 2 41 19.36 19 07 2 476 2 458 2 430 2 405 23 80 2 35 2 34 19 86 19.62 18 85 25 22 25 04 © American Astronomical Society • 2 73 26 49 25 77 25 44 26 34 2 703 A 2S69 6 9 2 5 1 7 4 7 3 74 74 74 72 73 73 72 7 1 7 1 72 6 9 6 9 7 0 6 8 6 5 6 6 7 6 3 6 4 6 0 6 1 44 50 53 56 5 8 40 4 1 4 7 40 40 4 0 40 . 61 . 21 20 25 24 22 2 1 20 30 28 26 4 1 37 34 32 56 52 4 8 4 59 6 1 1 5 1 5 20 20 2 1 2 1 5 9 6 0 1 9 1 8 20 20 5 9 5 9 20 20 20 5 9 5 9 20 5 9 1 9 1 9 1 9 1 5 1 5 1 3 1 3 1 O 1 O < arcs«) ( arcse) Log r Log r -0 09 -0.25 0 05 0 35 0 23 0 25 0 40 0 65 0.60 0 53 0 45 0 88 0 81 0 75 0 70 0 9 0 94 0 68 0.60 O 50 0.38 O 20 0 80 0 74 0.96 0.90 0 86 114 1 09 1 04 2 03 123 119 2 09 1.37 1.28 2 13 158 1.53 1 46 1 43 1.33 1.68 16 3 185 18 1 177 172 1 90 19 5 19 9 1.03 1 4 1 09 1 .35 1.30 1.24 119 1.43 1.39 153 148 173 16 8 1.63 1.59 1 86 182 1 78 03 08 9 9 5 FWHM OfPSF2.6FWMMof2.9 FWHM ofPSF30 20.52 20 01 2 113 20 96 20 76 20 24 2 1.73 2 1.34 22 68 22.26 22 08 2 1.90 2 1.54 18 30 16.06 23 46 22 92 22 45 19.02 18 53 23 89 2 370 23.20 19 .49 19.27 18 78 18.14 24 35 24 12 19 87 19.71 24 71 24 54 25.58 25 21 24 97 26.99 26 12 25 97 20 50 20.26 2 1.47 2 117 20 91 20 72 2 193 2 172 23 31 23 09 22 91 22 75 2 57 22 35 2 14 23 49 17 89 24 40 2 418 23 94 23 69 18.78 18 01 25 6 25 40 25 00 24 73 19 96 19 23 18.34 27.68 2 7.09 2 646 25 86 19 63 A2 6A270 49 67 6 7 65 6 67 46 6 4 64 6 5 63 6 3 6 3 6 3 63 63 6 3 6 3 6 3 6 2 6 3 6 3 6 3 6 2 6 1 6 2 6 2 62 6 4 6 5 6 5 65 6 4 6 4 59 60 60 65 6 5 6 5 6 5 5 9 5 9 65 6 5 65 6 5 59 6 6 6 66 6 7 6 68 68 6 8 6 7 6 7 70 6 9 73 72 7 1 70 76 76 75 74 6 6 TABLE 4—Continued Provided bythe NASA Astrophysics Data System . 27 . 21 . 17 . 30 . 35 00 20 77 77 20 20 23 23 2 1 20 24 24 23 24 24 25 25 24 24 26 25 25 1 8 27 1 8 30 29 28 26 E Logr 29 32 3 1 34 4 3 4 3 40 38 36 43 20 33 25 24 22 1 2 35 1 3 1 3 1 3 1 2 1 2 1 4 1 3 13 1 4 1 4 1 3 1 3 1 3 1 3 1 6 1 5 1 5 1 4 1 8 1 7 1 6 1 5 1 9 < arcsec) Log r -0.36 - O21 - O.11 -0.26 O 39 0 26 O .09 0.49 0 63 0.57 0.69 O .85 0 79 0 74 0 98 0 92 0.20 0 48 0.36 0 79 O 73 0.66 0.58 0 95 0 89 0 84 1 .08 1 .03 1.18 113 128 1.32 1.23 2 03 1 .53 147 1.42 1.37 1 08 1 .02 2 18 2.13 2 08 158 1.24 1.14 2 27 2 23 173 16 4 1 .50 1 45 1 40 1.19 16 8 1.71 1.66 1.55 1 .35 1 .30 178 1 .86 1.82 1.77 1 .60 188 183 1.91 193 198 00 08 04 96 1 3 FWHM ofPSF19 20.34 20 95 20 68 2 1.17 2 1.56 2 1.37 2 1.98 2 1.72 22.63 22.47 2 2,24 19.67 19.46 19 .39 2 315 22.94 22.78 19.96 23.32 24 14 23.68 23.48 20.29 20 07 24 75 24 42 23 92 25 12 2 144 2 1.20 20 99 20.71 20.48 25 26 25 03 2 1.63 25 73 25 45 2 36 22 42 2 16 2 1.85 23 84 23.54 23.14 22.91 22.64 17.45 25.87 25 .74 24 32 18 42 17.94 17.50 26 28 26 14 26.02 25.57 24 73 24.53 24 73 2 45 19 .83 19 55 19 23 18.87 26 77 26.77 25 .50 25.55 27 05 2 7.61 27 25 25 44 25.26 26 86 155 155 155 1 55 155 155 155 1 5 1 55 155 1 55 1 55 1 55 155 1 55 155 1 55 1 55 1 55 1 55 1 55 1 55 1 55 155 155 1 55 155 1 55 155 1 55 1 55 1 55 1 55 1 55 1 55 1 55 1 55 1 55 1 05 102 1 55 1 55 1 O 108 1 28 1 7 1 3 1 48 142 1 37 133 1 24 1 2 1 54 1 68 1 74 172 1 64 1 59 1 68 1 68 17 1 174 1 68 1 68 95 95 9 5 94 94 9 1 90 96 94 93 9 97 . 22 . 23 . 21 . 21 . 19 . 17 . 18 .14 . 06 . 06 . 1O . 1 . 06 . 06 . 20 06 06 06 06 06 06 06 06 06 06 0 6 06 06 06 06 06 06 06 20 20 06 20 06 06 06 06 06 20 20 2 1 06 06 06 09 06 06 08 1 7 06 06 06 07 08 0 6 06 08 07 0 6 06 06 06 06 1 6 1 5 1 5 20 2 0 1 3 1 2 1 1 9 1 5 (ar csec) < arcsec> Log r -0.37 Log r -0.22 -0 23 -0 09 O .08 0.38 0.26 0.63 0 56 0.48 0 39 0.21 O ,68 0.61 0.51 0.84 0.78 0 .73 0 81 0.75 0 69 0.97 0.91 0.91 0 86 0.97 1 .02 1.18 1.12 1.07 1 09 1 04 1.23 2 .OO 1.15 2 03 2 0 1 .36 1.32 1.27 2 05 124 1.19 1.52 1.47 1.41 1 .30 1 39 1 35 1.63 1.57 1.43 1.72 1.68 16 8 1.63 1.58 1.53 1.48 1.82 1.77 1 .80 1 76 1 72 1.92 1.87 1.95 1 90 184 1.97 FWHM ofPSF3.6 FWHM ofPSF1.6 20 20 20 20 2 1 2 1 20 22 2 1 2 1 1 8. 1 8. 1 8. 20 08 2 22 1 9. 1 9. 20.53 20 33 2 3 22 22 1 9. 1 9. 20.85 20.71 23 23 1 9. 2 1.39 20 95 24 23 2 158 2 1.16 24 24 2 1.80 18 60 22 18 2 00 19.79 19.41 18 9 18.44 25 25 22 73 22.65 22 41 26 26 25 23 52 23 32 23.16 22 92 25 26 24 36 24.26 24 02 23 72 26.07 25 39 25 09 24 64 26 29 25 69 MKWS 04 74 6 3 85 76 52 24 96 65 06 9 1 44 29 6 1 39 03 82 6 1 42 26 8 1 55 25 39 89 1 3 08 75 1 5 62 43 93 70 84 1 4 1 1 68 1 68 1 68 1 64 1 68 1 68 1 68 1 68 1 68 1 68 1 68 1 68 1 68 1 68 1 6 1 68 1 68 1 68 1 68 1 68 1 68 1 68 1 68 i 68 1 68 1 68 1 68 1 68 1 68 168 1 68 1 68 1 68 1 68 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 93 9 3 9 3 93 9 3 93 93 9 3 9 3 93 93 9 3 93 93 9 3 9 3 93 93 93 9 3 93 . 31 . 29 . 39 . 56 . 15 20 1 5 1 5 1 5 1 5 1 5 1 5 1 5 1 5 2 1 1 5 1 5 44 27 23 20 1 3 13 1 5 1 5 1 5 50 35 25 1 3 1 3 1 3 15 1 5 1 5 1 5 1 5 1 5 1 5 1 5 1 5 1 5 15 1 9 1 9 1 8 1 5 1 5 1 5 1 5 15 1 5 15 15 IS 1 5 1 5 1985ApJ. ..291 .... 8M - -1 -2 2 about 24.0magarcsec^ tometry isgoodto0.1magfromabout17.0arcsec surface brightnessprofilesfrom076.TheBCMgalaxiesin CD’s” inMKW5,AWM1,4,and7 run, andtheBCMinA2670wasobservedduring1981 A2147 andA2162wereobservedbyusinthe1982JuneKPNO were observedinthe1982May,1981December,June, December McGraw-Hillrun.Likewise,the“poorcluster for theseeightgalaxiesinFigure2.Nozero-pointshift has for theTRphotometry.Inthosecasescolors,about—0.27 been madeintheseplotsexceptfortheV—gandrcolors plot bothourprofile(dots)andeither076’sorTR’s(plussigns) axies allhavesurfacebrightnessprofilespublishedbyTR. We lack ofashiftallowsustojudgethequalityabsolute and 0.29mag,respectively,weretakendirectlyfromTR. This photometry fromFigure2.Onthewhole,agreement with these otherauthorsisquitegoodexceptfortheBCMgalaxy in does. SimilardeviationsareseeninA2162andAWM1,but in AWM 5wheretheTRprofilefallsoffmorerapidlythan ours in theskylevel.InAWM5 deviationstartsatabout21.0 about 24.0magarcsecand areprobablyduetouncertainty these twogalaxiesthedeviations startatasurfacebrightnessof 1982 June,and1981Decemberruns,respectively.These gal- mag arcsec"andcannotbe duetotheskyvalue.Theonly conclusion seemstobethateither TR’sphotometryoroursis wrong forthisgalaxy. The BCMgalaxiesofA2147,A2162,andA2670allhave Our photometrydisagreesslightly withthatoftheother © American Astronomical Society • Provided by the NASA Astrophysics Data System (ar csec> Log r -0.25 - 0.13 0.17 0.34 0.56 0.46 0.71 0.64 0 82 0.77 0.99 0.92 0.86 1 .06 110 1.15 1 .27 1 .20 1.31 1.45 1 40 1.35 1.60 155 1.49 1.65 176 1.71 1.85 1.81 00 05 9 1 95 20 30 25 35 1 5 1 0 FWHM ofPSF2. 20 13 20 33 20 98 20 73 20 51 18 40 2 1.20 18 76 2 1.58 2 1.41. 19.40 19.11 2 199 2 177 19.67 22 38 22 20 19 91 22 59 22.98 22 79 23 30 23.19 24 06 23 83 23.63 24 86 24 58 24 32 25 68 25 34 25 16 26 16 25 93 26 45 27 04 26.67 27.50 AWM5 AWM6AWM7 80 80 82 80 80 60 80 80 8 0 80 80 80 80 80 80 80 80 60 80 80 80 80 80 80 8 0 80 80 80 80 8 0 80 80 80 80 60 80 80 80 80 80 DYNAMICS OFLUMINOUSGALAXIES 0 12 0.25 0.25 0 25 0.25 0.25 0 25 0.25 O .25 0.25 0 25 0.25 0 25 0.25 0.25 0.25 0.25 0.25 0.25 0.26 0.26 0.26 0 26 0 26 0.26 0.27 0 27 0.27 0.27 0.28 0 28 0 29 0.29 0 30 0.30 0 30 0.30 O .30 O .30 O .30 (ar csec) Log r 0 28 0.12 0 40 O 57 O .50 0 69 O 63 0 77 0 73 0.90 0.83 O .96 1.06 1.01 1.11 1.22 117 1.30 1.26 1.35 1 TABLE 4—Continued 45 40 55 50 60 6 9 6 5 74 7 8 05 00 9 1 86 82 96 1 5 1 O FWHM ofPSF2.2 20.12 20.27 20 42 2 1.07 20.84 20.61 2 1.49 2 1.28 18.61 2 193 2 170 19 45 18.84 22.12 19.94 19.71 19 14 2 44 22.29 22.73 22.58 23.34 22.91 23 56 23 12 2 409 23 81 24.55 24 33 25 26 24 89 24 59 25 62 25.90 26.72 26 25 2 errors arenolargerthan0.1magdowntoasurfacebrightness photometry givesusconfidencethatbothourabsoluteand our our profileofA2147atlogr&1.6.Sincewehadonlyone5 when onlyoneshort(5minute)exposurewasobtained (see because oflowsignal-to-noiseratioexceptinthefewcases result ofdifficultyinthedeterminationskylevel,and not relative photometryaresatisfactory.Weestimatethat the minute exposureofthisgalaxy,anattemptwasmadetoextend of about25magarcsec".Theerrorsincreaseafterthat as a in the1"-8"rangethan076’s.Dressier(1978)alsofindsthat signal-to-noise ratioinourdatathiscase. authors inafewotherrespects.Thereissmalldeviation ments atlargeradiifromthe centerofthegalaxyaredifficult advantages anddisadvantagesofusingaCCDcamerato do this galaxy. large radii.Weconcludethatthedisagreement'sduetopoor short exposure.However,thisresultedinaraggedprofileat the photometrytolargerradiithanwasnormallydonewitha because ofthesmallsize CCDchip.Ontheotherhand, show thatthereisgalaxylight muchfartherout.Measure- profiles, basedonphotoelectrically calibratedphotography, about 100"-150".Thisistrue eventhoughthe076andTR surface photometry.Ourprofiles extendonlytoaradiusof Fig. 3). 076’s surfacebrightnessistoohighinthesameradiusrange in The comparisonofallthesegalaxieswiththe076andTR Our profileofA2670issomewhatlowerinsurfacebrightness Examination ofFigure2alsoservestoillustratetherelative 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 3 5 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 . 05 . 1 . 09 . 13 . 18 . 19 . 19 . 20 . 20 . 21 . 21 . 22 . 23 . 26 . 29 . 27 . 31 . 38 . 38 . 38 E Logr 00 08 1 4 20 1 7 25 24 1 9 33 36 38 38 38 < arcsec) 0.36 0 08 0.22 0.26 O .39 0.48 0.56 0 74 0.6 9 0.63 0 84 0.91 0.78 0.97 1.13 108 1 .03 1.19 1.23 1.32 1.28 1.37 1.42 1.52 1 .47 2 02 1 57 2 12 2.07 162 2.16 1.72 1.67 1.87 1 82 1 77 19 2 1.97 FWMM ofPSF2.8 20 09 18.77 20.23 18.83 20.35 19.14 18.95 20.68 20.50 19.35 20.82 19.56 20.95 19.77 2 1. 2 1.07 19.94 2 1 2 1 2 1.62 2 1.87 2 175 22.00 22.14 22.46 22 29 22.62 23 04 22.81 23.52 23 26 24 06 24.19 23.79 2 4.88 24 4 25 28 25.84 . 20 . 34 4 8 1 79 1 72 1 78 1 73 1 22 99 9 1,2 1 0 22 4 39 6 1 79 79 8 1 76 76 80 1 3 76 76 76 76 76 76 76 76 0 5 7 9 9 6 5 1 0 16 0.16 O .08 0.10 O 08 0.07 0.07 0.08 O .09 O 09 0.11 O 09 0.12 0.11 0 04 O 06 O 09 0.01 0.02 O 1 O .05 0 08 0.05 0 15 O 09 O 18 0 22 0.23 0.19 0 19 0.19 0 19 0 19 0 19 0.19 0.19 0 19 17 CM* 1 8 ^ i CD CM* OOCD ^'Si
CD CJ ÜJ CO
CM CO
Q oo CE CD CH CD
CD♦ CD I
CD CN CD CJ Z-LU CO CM CO -ID M CD s co Œ së 2 cd CE .3? a ¿ = CD 8 O u cn S ^ o ^ li cdC Ccd CD CD ° S V¡ < ri CT)1 CD ,2 S I < the Thuan and Romanishin (1981) profiles. 18 © American Astronomical Society Provided by the NASA Astrophysics Data System 1985ApJ. ..291 .... 8M rf 81 0222t’2928208tZ (2**G3S/3aniIN0HU)'rf (2*x03S/30niIN0tJUI' © American Astronomical Society • Provided by the NASA Astrophysics Data System 19 1 CD oJ CD CNJ o CM CO cdCTL oo Œ o — o o o CN CM CM CO -ID CD Cd oo Œ CD CD CD I I I « ♦ • I—I CO LÜ Q CJ M a U CN £ d o c 00s j 20 MALUMUTH AND KIRSHNER Vol. 291 Fig. 3.—Surface brightness profiles of A2589 from the McGraw-Hill data {dots) and from the KPNO data {plus signs). No zero-point shift has been made. The agreement is very good (better than 0.03 mag) from log r = 0.7 to log r = 1.5 (5"-34") and is good (better than 0.1 mag) from log r — —0.2 to log r = 1.7 (0"6-52"). the photographic photometry of 076 and TR contains no characterize the luminosity distribution of the 076 BCM information at radii less than T-T.5 from the center, while we galaxies, since these models offer a simple way to estimate the often obtain information, to within the limits of seeing, inside central density. While seeing effects make it hard to determine the central arcsecond. It should be remembered that because of the core radius, Rc, and the central surface brightness, /0 the small field of the CCD the “ total ” magnitudes in this paper (Schweizer 1979), it is the product /0^c which is important in may be too faint for the most extended of the galaxies. In the determining M/L, and this product is less affected by seeing worst case the total magnitude derived from the photometry of than is either parameter alone (S80; see also Paper I, eq.[5]). AWM 7 in this paper is 0.74 mag fainter than TR’s value. We attempted to fit a King (1966) model to each of the AWM 7 is one of the closest galaxies and is the most extended galaxies observed here, taking the seeing into account. An esti- BCM galaxy in this sample. The total magnitudes of A2147, mate of the seeing was made for each frame by looking at the A2162, A2670, and AWM 4 are about 0.3 mag fainter than the light distribution of a star in the field. The luminosity distribu- 076 or TR values for these galaxies. The total magnitudes of tion of this star is the point spread function (PSF) of that frame. the others agree better than this. We use the total magnitudes The full width at half-maximum (FWHM) of the PSF is given of 076 or TR for these five galaxies in the analysis in § IV. for each galaxy in Table 4. Following Schweizer (1979), we As a check on the consistency of the photometry between the convolved the PSF with the King (1966) model and fitted the two telescope-camera combinations used in this work, one convolved model to the luminosity profile of the galaxy. Since galaxy, the BCM in A2589, was observed with both telescopes the King (1966) model is dimensionless, a core radius, Rc, and and reduced separately. Figure 3 compares the profiles. The central surface brightness, /0, were assumed before the convo- agreement between them is good to a surface brightness about lution was done. The convolved model was then plotted with 25 mag arcsec-2. The magnitude difference is less than 0.1 mag the data. The distance between the model and the data along -2 in the range from 0'.'6 to 52" (19.0-24.3 mag arcsec ), and less each axis was used to make a better guess of the values of Rc than 0.17 mag (peak to peak) out to a radius of 74" (about 25 and 70. The process was repeated until a satisfactory fit was mag arcsec-2). The agreement is very good (better than 0.03 obtained. Of the 27 BCM galaxies observed in this paper, 15 mag) in the 5"-34" range (20.8-23.7 mag arcsec-2). After that, were fitted well from the center out to a surface brightness of uncertainty in the sky leads to a larger disagreement between about 24 mag arcsec-2 by the seeing-convolved King (1966) the two profiles (0.5 mag at 135", or about 26.5 mag arcsec-2). models, while six others (A505, A1631, A2029, A2107, A2589, Again this comparison gives us confidence in our absolute and and MKW 5) could be fitted approximately. That leaves six relative photometry, and a knowledge of its limits. (A401, A496, A2052, A2124, AWM 4, and AWM 7) for which no satisfactory fit could be obtained. These galaxies have d) The Luminosity Distribution of BCM Galaxies smaller cores than the other galaxies, and have a shallower One interesting result of Paper I was that the seven BCM falloff of their light with radius than all but three of the other galaxies showed a higher central mass-to-light ratio than the galaxies.105 The surface brightness of the BCM in AWM 7 falls -as2 elliptical galaxies. To determine these core mass-to-light ratios r- over a range of 4"-40", as compared with the r we require an estimate of the central density (King and Min- profile of the Hubble law (Hubble 1930)! The parameters of the kowski 1972; FJ; S80). King (1966) models were used to King (1966) model fits are given in Table 5. The surface bright- © American Astronomical Society • Provided by the NASA Astrophysics Data System 1985ApJ. ..291 .... 8M i/4 No. 1,1985 fitted. on theseplots,exceptforthesixgalaxieswhichcouldnot be best-fitting seeing-convolvedKing(1966)modelisalsodrawn ness profilesofall27BCMgalaxiesareshowninFigure4. The not fittedbyKing(1966)modelswerebetween2" and envelopes (A2670,forexample); inthosecasesandM model (M,absolutemagnitude ofthedeVaucouleursR ence ofanenvelopeinsomethegalaxies.Theeffective galaxy. Notethatsomeof thesegalaxieshaveluminous law (M\andthederivedcore mass-to-lightratio,foreach absolute magnitude,magnitudeoftheKing(1966) are alsolistedinTable5,alongwiththevelocitydispersion, radius, R,andthesurfacebrightnessateffective 7, by seeing,andtheouterregion,whichisaffectedpres- 50". Thisrangeavoidsboththeinnerregion,whichisaffected without itsenvelope.Wediscuss themass-to-lightratiosin§ are smallerthanMandrepresent themagnitudeofgalaxy 1958) between1and25coreradii.Thesixgalaxieswhichwere vd vK vd e e v 1/4 Each galaxywasalsofittedtoanÆlaw(deVaucouleurs e a 3 a 8 g Schild andDavis1979. AWM 5 AWM 7 AWM 6 AWM 4 AWM 3 AWM 2 AWM 1 A2670 A2666 A2634 A2457 ...... A2366 A2162 Virgo (M87) A2589 A2199 A2147 A2124 A2107 A2052 A2029 A1904 A1631 A1177 A994 A779 A505 A496 A401 A150 MKW Is... MKW 5 MKW 2.... MKW 4'!... a f d c J h 8 e b 1 SurfacephotometryfromOemler1976. Velocitydispersionistheaverageofthreevaluesinthispaper. VelocitydispersionisaweightedaveragebetweenFaberandJackson1976(weight2)thispaper1). Surfacephotometryfromthispaper;totalmagnitudeOemler1976. Surfacephotometryfromthispaper;totalmagnitudeThuanandRomanishin1981. ThetotalmagnitudefromThuanandRomanishin1981correctedforsomeconfusionbetweentheredshiftsofMKW22sin SurfacephotometryfromThuanandRomanishin1981. TotalmagnitudefromOemler1976;surfacephotometrynotavailable. VelocitydispersionfromDressier1979. SurfacephotometryfromOemler1976,withzero-pointcorrectionThuanandRomanishin1981. © American Astronomical Society • Provided by the NASA Astrophysics Data System Cluster b d f 206 375 426 477 438 408 416 249 279 254 245 228 278 247 213 243 391 380 342 306 330 372 367 327 328 364 343 363 397 346 335 197 j j h c c c Parameters ofFitstotheSurfacePhotometryBCMGalaxies - 24.68 -24.24 -24.63 -23.95 -22.83 -23.08 -23.43 -22.83 -23.10 -23.96 -24.29 -23.53 -25.23 -23.81 -24.50 -24.32 -23.83 -24.25 -24.89 -23.95 -24.57 -24.32 -24.31 -24.30 -25.40 -24.40 -22.53 -24.03 -23.30 -23.65 -24.65 -24.16 -24.33 -24.43 DYNAMICS OFLUMINOUSGALAXIES (kpc) 0.50 0.72 0.73 0.70 2.02 2.64 2.40 2.63 2.36 2.66 6.18 2.84 3.41 3.26 3.35 5.20 1.75 1.63 1.51 1.12 1.60 1.20 1.38 1.70 1.23 1.11 R c 2 (mag arcsec) 18.00 19.25 17.60 18.55 17.45 18.00 18.67 17.79 19.30 17.35 18.70 18.65 19.42 18.50 17.70 17.00 17.35 18.80 18.40 17.80 17.80 16.65 17.05 17.85 18.87 18.05 ¡0 TABLE 5 4 from thisworkorWK. The fivegalaxiesfromWKwere elliptical galaxies.Thechiefreasonformakingtheobserva- tudes fortheEgalaxiesaretaken fromeithertheSecondRefer- almost identicalwiththoseobserved inthiswork.Themagni- persists withalargersampleof BCMgalaxies. tions describedinthispaperwastoseewhetherconclusion observed withthesametelescope andinstrumentinamanner sample werebrighterthanpredictedbytheLocarelation for isophote measuredhere.Inthosecasesthe076orTRmagni- tudes arelistedinTable5. photometry showsthatthereismorelightbeyondthe last under thedataobtainedhere,exceptwhere076or TR lYd. Theabsolutemagnitudesinthistablearefromintegrating Table 6lists29ellipticalgalaxies withvelocitydispersions We showedinPaperIthattheeightBCMgalaxies 45.70 42.17 91.04 48.22 23.66 23.30 23.23 34.60 37.53 77.54 84.44 37.61 38.52 59.65 70.80 29.88 30.44 50.66 50.15 (kpc) 30.88 37.39 32.90 12.32 19.95 11.90 19.13 16.44 11.41 10.32 18.31 17.19 17.33 7.12 (mag arcsec 23.18 21.90 24.12 22.64 24.19 23.10 22.94 23.92 22.42 23.73 23.56 23.77 24.73 24.34 23.55 22.77 23.09 21.98 22.79 23.45 24.51 25.29 24.35 24.58 23.16 23.01 23.76 21.80 22.10 22.94 22.93 23.31 23.28 l a) LversusoforBCMGalaxies e IV. DISCUSSION -24.17 -24.24 -23.34 -24.55 -23.80 -24.30 -23.81 -24.03 -24.28 -23.66 -24.23 -24.34 -25.47 -24.49 -22.48 -23.97 -23.34 -23.58 -24.52 -24.23 -24.49 -22.45 -22.89 -23.39 -23.07 -24.27 M,,. -24.20 -23.46 -24.37 -23.74 -24.09 -23.71 -23.89 -24.56 -23.64 -23.93 -24.27 -24.32 -24.70 -25.26 -24.30 -22.66 -23.73 -23.25 -23.69 -24.43 -24.35 -24.48 -24.04 -24.65 -24.18 -24.41 -24.08 -22.44 -22.95 -23.33 -22.80 -23.21 -24.29 M, n (M/L) 0vQ M/L 13.5 10.7 18.4 10.1 15.9 10.0 12.0 13.5 11.8 9.5 9.1 4.7 4.1 6.7 6.7 6.7 6.3 8.7 8.6 8.9 5.7 6.9 2.7 8.6 5.3 21 00s 22 Vol. 291 O'! CM h) ft LO CO00 -0.4 0.0 . 0.4 0.8 1.2 1.6 2.0 2.4-0.4 0.0 0.4 0.8 1.2 1.6 ZO Z4 LOG RADIUS (SEC) LOG RADIUS (SEC) Fig. 4.—Surface brightness profile of all 27 BCM galaxies. The best fitting King (1966) model is also plotted for each galaxy, except for the six which could not be fitted well. ence Catalogue of Bright Galaxies (de Vaucouleurs, de 29 E galaxies, while the open symbols are the BCM galaxies. Vaucouleurs, and Corwin 1976, hereafter RC2) or 076. Com- The line is the fit given in equation (1). Of the BCM galaxies, a parison of eight elliptical galaxies in 076 with the magnitudes subset of 18 have been classified as cD galaxies by Morgan and in the RC2 shows no signficant differences for elliptical gal- his coworkers (Matthews, Morgan, and Schmidt 1964; axies. As shown earlier, the photometry in this paper agrees Morgan and Lesh 1965; MKW; AWM; Bautz and Morgan well with that of 076 for BCM galaxies, except that our pho- 1970). From here on we will refer to this subset as the “ Morgan tometry does not go as far out in some of the galaxies. cD’s.” The Morgan cD’s are indicated in Table 7. This is not to A fit of log o versus was made for these 29 E galaxies. A say that the other BCM galaxies would not be called cD’s by 4 37 0 43 mean relation of the form L oc o- - * - was obtained from Morgan, but only that they were not so classified in one of doing the regression both ways. Since this is not significantly these papers. The Morgan cD’s are plotted in Figure 5 as open different from L oc cr4, we constrain the slope to be 0.1 in the squares. log (7-Mv relation. The best fitting line in the log (t-Mv plane is Inspection of Figure 5 shows that while some of the BCM galaxies are far from the line, others lie along the extension of log © American Astronomical Society • Provided by the NASA Astrophysics Data System 00s j No. 1, 1985 23 O'! CM h) ft LO CO00 -0.4 0.0 0.4 0.8 1.2 1.6 2.0 Z4-0.4 0.0 0.4 0.8 1.2 1.6 2.0 Z4 LOG RADIUS (SEC) LOG RADIUS (SEC) Fig. 4.—Continued BCM galaxies, we see that the BCM galaxies average 1.22 mag AL = Lv — L^, from equation (1) for the elliptical galaxies and brighter. This is true even though the average velocity disper- the BCM galaxies. The luminosity residuals of all of the BCM sions are almost the same (279 km s~1 for the 19 BCM galaxies galaxies are listed in Table 7. The Morgan cD subset of the and 277 km s"1 for the 21 E galaxies in the range 193 km BCM galaxies is shown in cross-hatching. The elliptical gal- s-1 < cr < 346 km s"1). Histograms of the magnitudes of the E axies have small residuals in L, and the distribution is sym- galaxies and the BCM galaxies in this range of velocity disper- metric about zero. The BCM galaxies, however, are scattered sion are shown in Figure 6. It is clear that no matter what the in a flat distribution with most (23 of 32) galaxies having posi- relation is between luminosity and velocity dispersion, where tive residuals. The Morgan cD subset of the BCM galaxies there is overlap the BCM galaxies are more luminous than the have an even higher percentage of positive residuals. Fifteen of E galaxies of the same velocity dispersion. It is interesting to the 18 Morgan cD’s have positive residuals. That leaves eight note that if the BCM galaxies alone were plotted in Figure 5, of the 14 other BCM galaxies with positive residuals. Fourteen there would be only a weak relation between L and a. The of the BCM galaxies have positive residuals greater than 11 velocity dispersion is a poor predictor of the luminosity of a 2 x 10 L0, while only one has a negative residual of that BCM galaxy. The reader should also bear in mind that since size. Of those 14 galaxies, 10 are Morgan cD’s. 4 this is a log-log plot, equal residuals in L and a will appear to The location of most BCM galaxies to the right of the L-cr be smaller near the upper right-hand corner of Figure 5 than in line in Figure 5 presents an interesting question for interpreta- the middle of the plot. tion. It might have its origin in the selection of the sample. For In Figure 7 we plot histograms of the luminosity residuals, example, if galaxies of a given a have a range in M, then © American Astronomical Society • Provided by the NASA Astrophysics Data System 00s ï—i: 24 MALUMUTH AND KIRSHNER Vol. 291 CM h) ft LO co00 -0.4 0.0 0.4 0.8 1.2 1.6 2.0 2.4-0.4 0.0 0.4 0.8 1.2 1.6 2.0 2.4 LOG RADIUS (SEC) LOG RADIUS (SEC) Fig. 4.—Continued picking the brightest galaxies in a cluster will select galaxies cluster. We start with the assumption that L oc © American Astronomical Society • Provided by the NASA Astrophysics Data System 00s • No. 1, 1985 25 O'!ï—i ’ CM ^0 ft 00LO -0.4 0.0 0.4 0.8 1.2 1.6 ZO 2.4-0.4 0.0 0.4 0.8 1.2 1.6 2.0 2.4 LOG RADIUS (SEC) LOG RADIUS (SEC) Fig. 4.—Continued observations are not drawn from the population produced by effect must be smaller than 0.76 mag; however, it still may be the selection model is 99.9%. Inspection of the two distribu- significant. If we assume that selection biases the mean abso- tions shows that while the model can account for AL values as lute magnitude of the elliptical galaxies to be too bright by 0.4 large as those seen, it does not account for the substantial mag at each cr, the observed distribution of AM values shown number of small values of AL. Too few model clusters have a in Figure 7 for the BCM galaxies would be shifted 0.4 mag to brightest galaxy with AM < 0.45. To be precise, 19 out of 150 the right. This would make the observed distribution more model clusters have values of AM as small as 0.45 mag, while like the model distribution. Applying the Kolmogorov- 15/32 in the real sample have such modest deviations from the Smirnov test shows that the probability that the shifted BCM mean relation. This statistical model usually produces a large galaxies are not drawn from the model distribution is only residual, while the observations show that small residuals are 75%. The present sample of elliptical galaxies is not well also common. enough understood to say whether a Malmquist bias of about Since the elliptical galaxies used in this paper are not drawn 0.4 mag is reasonable. A better understood sample of elliptical from a volume-limited sample, it is possible that they suffer galaxies is necessary before we can conclude whether this from a Malmquist bias. If the ellipticals were a magnitude- simple picture in which o is the independent variable and M limited sample, then the mean absolute magnitude at a given has a spread can account for the observed distribution in AL. velocity dispersion would be too bright by about 0.8 mag for a The fact that many of our clusters are Bautz-Morgan type I dispersion in Mv of 0.76. The sample of elliptical galaxies was or type I-II means that we emphasize clusters where the chosen for convenience and is not magnitude-limited. The brightest galaxy is much brighter than the second brightest. © American Astronomical Society • Provided by the NASA Astrophysics Data System MALUMUTH AND KIRSHNER Vol. 291 -0.4 0.0 0.4 0.8 1.2 1.6 2.0 2.4 LOG RADIUS (SEC) Fig. 4.—Continued TABLE 6 Applying the same criterion to the simulations makes the Elliptical Galaxies derived distribution even less like the observations, since it emphasizes the cases with large AL. An interesting investiga- Galaxy tion would be to observe a sample of Bautz-Morgan type III or NGC 533... 284 -23.79 type II-III clusters of comparable richness. In those clusters, NGC 636 .. 174 -21.68 mergers are not expected to play a major role. If there is no NGC 1052 193 -21.75 statistical effect of the type we have investigated here, then the NGC 1209 281 -22.27 NGC 1272 344 -22.87 NGC 1273 259 -22.29 NGC 1278 , 245 -23.02 NGC 1400 250 -21.05 NGC 1426 153 -20.55 NGC 1521 296 -23.12 NGC 2672 332 -23.02 NGC 2693 297 -23.24 NGC 3377 186a -20.64 NGC 3379 246a -21.59 NGC 4374 299 -22.36 NGC 4387 165a -19.72 NGC 4406 244 -22.52 NGC 4458 176 -19.65 NGC 4467 102 -17.23 NGC 4472 343 -23.33 NGC 4473 203 -21.55 NGC 4478 127a -20.50 NGC 4551 132a -19.83 NGC 4564 245 -20.76 NGC 4649 324 -22.87 NGC 4692 230 -23.12 Fig. 5.—The log of the velocity dispersion versus absolute visual magni- NGC 4874 311 -23.83 tude for elliptical galaxies (filled circles) and the BCM galaxies (open symbols). NGC 7626 310 -22.91 The line is the best fit of the L cc © American Astronomical Society • Provided by the NASA Astrophysics Data System 1985ApJ. ..291 .... 8M formation. merger, butitsvelocitydispersion remainsunchanged(see discussion inthispaperisrestricted tothemergermodelsofcD in thissamplearericherthanrichnessclass1,tidalstripping (1984) confirmthattheimportanceofstrippingisstrongly should notbeveryimportant formostofthegalaxieshere.The dependent ontheclusterrichness.Sinceveryfewofclusters photometry heredoesnotextendfarenoughouttomeasure from clustergalaxiesandformsanenvelopearoundthecentral results inPaperI,themodelsofMalumuthandRichstone the envelopesofmanygalaxies.Assuggestedby the galaxy bygatheringintheclusterpotentialwell(Richstone product whichishomologouswiththeinitialgalaxies.Another first approach(OH;HO)isthateachmergerresults in a in thecentersofclustersgalaxies(OH;HO;Richstoneand Paper I;seealsoOHandHO). Thismodelalsopredictsthat picture ofcDformationisthatluminousmaterialstripped ture inwhichcDgalaxiesaretheproductsofgalaxymergers Malumuth 1983;andRichstone1984).Asimple tion thatresemblesthesimulationresults. the statisticaleffectsdominate(andmergersareirrelevant)then distribution ofALintheseclustersshouldresemblethedis- No. 1,1985 the BCMgalaxiesintheseclustersshouldhaveaALdistribu- tribution forEgalaxiesseeninFigure7.Ontheotherhand,if 1975). Wewillnotdiscussthisprocessinpaper,since the In thismodelaBCMgalaxy grows inluminositywitheach Another possibleexplanationfortheALrelationispic- AWM 7.. AWM 4.. AWM 6.. AWM 5.. AWM 3.. AWM 2.. A WM1.. MKW Is. A2670 .... A2666 .... A2634 .... MKW 5.. MKW 4.. Virgo .... A2589 .... A2457 .... A2366 .... A2199 .... A2162 .... MKW 2.. A2147 .... A2124 .... A2107 .... A2052 .... A2029 .... A1904 .... A1631 .... A1177 .... A994 A779 A505 A496 A401 A150 Cluster c) ALasaMeasureofDynamicalEvolution © American Astronomical Society • Provided by the NASA Astrophysics Data System n AL(10 M) q Structural Parameters -0.8 -1.5 -0.6 -1.3 -0.1 -5.9 -1.7 -0.2 -0.8 4.3 0.8 2.3 2.3 0.9 5.7 2.7 0.3 4.3 5.1 2.2 4.3 4.3 9.1 0.2 2.5 4.5 1.7 1.2 3.3 1.0 1.6 1.6 TABLE 7 1.05 1.50 1.54 1.43 1.71 1.65 1.61 1.64 1.64 1.51 1.73 1.89 1.56 1.58 1.32 1.87 1.67 1.62 1.65 1.54 1.47 1.54 1.22 1.43 1.65 1.52 1.37 1.98 1.62 1.63 1.29 1.44 1.57 a(16) MorgancD? 0.93 0.72 0.72 0.77 0.35 0.44 0.59 0.58 0.57 0.74 0.72 DYNAMICS OFLUMINOUSGALAXIES 0.48 0.85 0.60 0.82 0.65 0.66 0.85 0.75 0.56 0.77 0.80 0.95 0.97 0.77 0.49 0.65 0.47 0.61 0.78 0.89 0.98 0.84 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 1_ -1 -1 than thedistributionofBCMgalaxies asawhole. areas andhaveadistributionofresiduals whicharemorepositiveandlarger residuals, manyofthemquitelarge. TheMorgancD’sareshowninhatched and symmetricaboutzero,whilethe BCMgalaxieshavemostlypositive galaxies andBCMgalaxies.Theresiduals oftheellipticalgalaxiesaresmall galaxy. magnitude mayrepresentasinglemergerforsmallgalaxyor decrease withtheM—residualinapproximatelyway several mergers(oronemergerwithalargergalaxy)forlarge luminosity residual,AL=L—,sinceanequalchangein predicted byhomologousmergermodels.Herewewillusethe a(16), willincrease,andthesurfacebrightnessdecrease are almostthesame(279kms~forBCMgalaxiesand277s the rangeofvelocitydispersions,eventhoughaveragedispersions km s.TheBCMgalaxiesaverage1.22magbrighterthantheEin we sawthatforthesmallersampleRdidincreaseandI with eachmerger(OH;HO).Herea(16)isdefinedas[d(lnL)/ the radius,R,andlogarithmicderivativeofluminosity, E galaxies). this model,theluminosityresidualofaBCMgalaxyinFigure d(\n R)']=.Sincethevelocitydispersionisconstantin BCM galaxieswithvelocitydispersionsintherange193kms