In Tig* 1b two supsrdueters can be seen: the Pegasus eupercluster in the sight-hand section of the figure and the. Cetus eupercluster in the lower left-hand ...
EESTI NSV TEADUSTE AKADEEMIA PttttSIKA-MATEMAATIKA- JA TEHNIKATEADUSTE OSAKONO ДСАОЕМУ OF SCIENCES OF THE ESTONIAN SSR, DIVISION OF PlftsiCAL, MATHEMATICAL A N D T B C H . V I C A L SCIENCES
Preprin£A-3(l979) Einasto, Mihkel Joeveef,
SUPERCLUSTERS AND GALAXY FORMATION Tartu 1979
ACADBIff OF 3C1BSCBS OF TBS JSTOHIAH S3H D1VXSXOI OF PHYSICAL' MATHEMATICAL AND TBCHIICAL SCIBICES
Preprint A-3 (1979)
SUPffiCLUSTIRS AID OALAIY FORICATIOV Jaan Xlna«to v
Mihlc«l J 5 « r « e r
TARTU 1979
and
Enn Sear
Paper prepared for publication in the Institute of Astrophysics and Atmospheric Physics Tartu, Tdravere, Estonia, 202 444 USSR С
Academy of Sciences of the Estonian. SS2, 1979*
Superclusters and galaxy formation Recent studies hare demonstrated that most galaziae and rich clusters of galaxies are concentrated to superolusters of galaxies, large boles are situated between superclusters 2 In this paper we study the structure of superclusters using Zwlcky clusters' as principal tracers of the large-scale structure of the Universe. Our study is restricted to the southern galactic hemisphere. Using Buohra's compilation of available redshifts of galaxies we have found mean redshifts of Zwicky dusters of distance class "near" between 22*^=*,^ 4 h , Of the 88 dusters in the area considered 56 hare measured redshifts* She redshifts of the remaining 32 clusters hare been estimated on the basis of luminosity function and apparent diameter* She distribution of clusters in the sky in two redshift intervals is given in fig*1* The prominent triangle-shaped aggregate seen in fig. 1a is the Perseus superoluster. Its richest cluster 1426 is located at the northern tip of the eupereluster* Rich dusters are situated in the western and southern tips as well, the Perseus cluster and A194» respectively* Other clusters form chains joining the tips of the superduster* A chain is located close to the Milky Way, it forms the northern boundary of the Andromeda superoluster* In Tig* 1b two supsrdueters can be seen: the Pegasus eupercluster in the sight-hand section of the figure and the Cetus eupercluster in the lower left-hand section* In the central area of fig* 1b there are no dusters, here lies a big hole* The hole is surrounded by superclusters from all eldest the Perseus superoluster forms a wall at the near side.of the hole, superclueters ssen in fig* 1b form walls at the left and right sides, superolusters at redshlfte 10000£V 0 < 15000 km s~1 form walls at its far side*
- 4 She distribution of Yedahifta of galaxies in the contra! area of the Peraeue auperoluater (where there are во dust ere) ia given in fig* 2a, fig* 2b gives the dlatribution of redehlfta of dusters of galaxiea In the whole area of the Pereeua aupercluater, and fig. 2c abowa the dietributlon of redehlfta of oluatara in the remising area outeide the Feraena aupercluater. We aee а тегу atrong peak In Figa* 2a and 2b at 'the redahift 5000 km a"1 due to the Peraeua auperoloater. She distribution of redahifta of galaxiea and eluatera at large redahifta la aleo almilar* fbia auggeata that (a) galaxies sitwated in the central area of the Peraeua aupercluater fora a thin atrattm just at the ваше dletanoe aa clastera fora ohaina, and (b) «oat distant galaxiea belong to diatant aupercluatera* She distribution of redahifta in Tig* 2o la completely different since it la oauaed by other auperoluatera aituated at a larger diatanoe from ua« In the direction of the Peraeua auperoluater there are only a fa» foreground and baokgroond. galaxiea» the vaat majority of galaxiea between 13*0 < a ^ 15*0 belong to the Vmrwum aupercluster* Xhua «a can uae galaxy oounte to eatimate acme numerical properties of the Peraeua aupercluater. Пл reaulto are glren In Pig. 3« > denotea the number of Palomar Obeerretory Sky Surrey fields, L - the luminoaity calculated by the method euggeeted by Joereer, Binaato and fago^, В is the aurface brightneaa and %3 ia the per cent of spiral galaxiea in the reapective area* morphological tjpea of galaxies were taken from Ш а о п • In the laat column the number of radio galaxiea la glven^* She data given in Tigs* 1 - 3 indicate that aupereluatera of galaxiea art> aurrounded by chaina of cluatera of gaaxLea which join main density peaks - rich oluatera. Main peake hare a low spiral percentage (moat galaxLes are elliptical and SO-s) and contain many radio galaxiea* In central areas of supercluetera the denaity of galaxiea ia amall, there are no cluatera here, almost all bright galaxiea are spirals. The total area covered by the Peraeua aupercluater ia
- 5 5400 *pc 2 , ite mean thiekaoee la 7 Щс, volwe 3*8 • 1 0 4 abeyant a u i (adopted м ш maaa-to-lumlaoalty ratio 150) 2.7 • W f t *o . D w mean denaity in the auperoluater ezocede tenfold* the erlt» ioal coamologleal denaity • leigbbouring aupereluetera «re la contsot and oontala •on clemeata* Jbr example, the chain of oluatere between oil tare A426 and 06 la the northern boundary of the Peraeua auperolaater and the aouthern boundary of the Andromeda euperoluater* All oluatera are — b e r a of eupereluetenu She apace between anperclnetere (about 980 of the total roluae of the unlTeraei ia Told of eluatera and alaoat void of bright galaziea* A nonlinear theory of the growth of inhoaogeneitie* auggeate that the aaouat of amtter oonoentrated in auparoluatera (initial poaitive denaity perturbatioaa) ia only a little larger than the total aaea of the drirk amtter ia big holea (initial negatiTe denaity perturbatlona) « If the denaity of natter aaaociated with auperoluatera ia ^ a c x s °»2^» than the overall веап amtter denaity ia Л * 0.3» The different largeVeoale epatlal diatribution of dark and lualaoua amtter cannot be reconciled with gravitational cluaterlag theoriea 10 . On the other hand, the morphology and etruoture of aupercluatere auggeat that It la iapoeeible to form auperoluatera la a wholly gaaeoua medium* In a gaaeoua proto-enpereluater the fozmatlon of galaziea haa to begin la the central part of it and lead to a large cluater of 1 galaziea rich in elliptloala la the center of the auperoluater '• Aa the auperoluater growa outwarda, ita edgea become thinner, moat galaziea ahould be apirala here* She obaerved atructure ia juat the oppoaite* Thie difficulty can be avoided if we auppoae following Beea that the foxmation of galaziea waa a two-atage proeeaa* 2 * 13 , but involvea much larger epatial dlmenaiona than he thought* In the firat atage proto-auperoluetera and big holea had to 1 form from the non-dieeipative dark matter ** Aa demonatrated by numerical almulatloaa non-dlaaipative matter forma eventually duet the obaerved atructure with high denaity tipa,
- 6 intermediate density chains and low density «alls, if the initial spectrum of perturbations contains large scale components • In the second stage hot gas* cooling and settling down into the potential wells caused by dark natter» will fora galaxies and clusters of galaxies1 •
June, 1979 Tartu Astrophyslcal Observatory Torarer» 202 444» Srtonia, USSR
Jaan Sinasto Xihkel Joereer Bra Saar
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m
Ubell» 0.0., Astropbys. J. Suppl., 2» 211 (1998). Joeveer, M., Binasto, J» and Tago, 2., Tartu Astr. Obe., preprint A-1,(1977). ^Joeveei», SU, Slnmsto, J. and Tago« B., Hon. lot. R. astr. S o c , J ^ , 357, (1978). 2
^Gregory, S.A. aad Thompson, L.A., Astrophys. J., 222. 764 (1978). ^Tarenghi, M., Tifft, W.G., Chincarinl, H., Rood, H.J. ant' Thoapaon, L.A., She largo-scale structure of the Univax-ee, p a 257t eds. Longair, K.S. and Elnasto, J., D. Beidei, Dordrecht, Holland, (1976). Sinasto, J., Joeveer, M. and Saar, B., Tartu Astron. Obs« Preprint A-2 (1979). 'Zwicky, Ï., Wild, P., Hersog, B.t Karpowics, M. and Koval, C«s Catalogue of galaxies and clusters of galaxies, 1 - 6c Cal. Inst. Tech., Pasadena, 1961 - 1968. Wilson, P., Uppsala General Catalogue of Galaxies, Uppsala Astron. Obs. Ann., Band 6.(1973^. ^de Taucouleurs, G., de Vaucouleurs, A. and Corwin, H.G., Second Reference Catalogue of Bright Galaxies, University of Texas Press» Austin and London,(1976). 10 Aarseth, S.J., The large scale structure of the universe» p. 185, eds. Longair, 1US. and Sinasto, J., D. Beidel, Dordrecht, Holland (1978). 1
'Doroshkevich, A.G., Shasdarin, S.V., Saar, B., Mon. lot. R. aatr. S o c , r§£, 643 (1978).
12
Rees, M» J., The evolution of galaxies anâ stellar populations, p* 339» eds. B.I. Tinsley and R.B. Larson, Tale University Observatory (1977)*
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14 15
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Wilt», S.D.M. «ad •»««, H.J., Moru let* R, astr. 8oo«, 163. 341 (1978). S u r , !•, itotn iftr. Obe,, pr#prU»t A-4 (1979). DoroehlWTloh, A.O., Hotok» !••., lorlkor, J.B., Polju^or, Sigort la.e. «nd Sbandarin» S.f», last. Appl. Preprint Ю . 83 (1978). Saar, I», farto aetroiu Obe, zvtpdat 1-5 (1979)*
- 9 Vigore caption* Jig- 1- B w dlatrlbutioa of Zwicky olaete/a (•) between redablfta 3500 * Y O < 6500 km e" 1 , and (b) b t t m n redahlfta 6500£Y o «10 000 кш Г 1 , ftrlcky oloatera with ш м и и Д redahlfta "bava been dram by eolid llnea, toe olnatera «ath eatlaatad redanifte by daaned llnea* Abell olwtera bare been denoted aa tilled eirclee, xadio falazlea by exoaaea, Z-raj aonroea by trlanglea* »i»- g> fne diatribution of redafeifta of (a) ealttlea in the central area of the Pereeue euperolnater (10 Palcaar auxrey flelda)» (b) 2»ioky olnatera in the «mole Peraeua euperclaeter area» and (o) Swicky oluatera ontaide the Pereeoe euperolneter
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Pig. 1a
23»
Ы.
22
к
Fig. 1b
23*
*
22"
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a) Gala*** in tht "vrseus supercluster central area
b\2m. dusters in the Pfcrseus super cluster
fig.
