000048157 001__ 48157
000048157 005__ 20170612100522.0
000048157 0247_ $$2doi$$a10.1051/0004-6361/201423728
000048157 0248_ $$2sideral$$a87378
000048157 037__ $$aART-2014-87378
000048157 041__ $$aeng
000048157 100__ $$0(orcid)0000-0002-6833-7289$$aMembrado, M.$$uUniversidad de Zaragoza
000048157 245__ $$aEffects of the cosmological constant on cold dark matter clusters
000048157 260__ $$c2014
000048157 5060_ $$aAccess copy available to the general public$$fUnrestricted
000048157 5203_ $$aContext. Cold dark matter inhomogeneities are considered in a homogeneous background of matter, radiation, and the cosmological constant in a flat universe.
Aims. We investigate the influence of the cosmological constant on the non-linear collapse of cold dark matter clusters.
Methods. For simplicity, a spherical infall model has been used to describe the collapse of non-relativistic mass shells; besides, an average distribution of density around a cluster of galaxies has been taken. Boundary conditions are imposed by the solution of the linearized equation for the growth of matter perturbations and by the cold dark matter power spectrum.
Results. For an average cluster, the radii of shells and masses enclosed by them have been obtained at their zero proper accelera- tion (ZA) redshifts, at their turn-around (TA) redshifts and at their virialization (VIR) redshifts. According to our results at present, the shell that reaches its turn-around point shows [rTA]0 = 6.85 Mpc and [MTA]0 = 6.76 × 1014 M¿. The virializing shell fulfills [rTA]0 = 4.57[rVIR]0 and [MTA]0 = 1.95[MVIR]0. These results differ appreciably from those derived from a model with cosmolog- ical constant equal to zero in a flat universe: [rTA(¿ = 0)]0 = 6.62[rVIR(¿ = 0)]0 and [MTA(¿ = 0)]0 = 5.26[MVIR(¿ = 0)]0; this discrepancy could be considered as a new independent proof of the existence of dark energy. The shell with zero proper acceleration presents [rZA ]0 = 1.59 [rTA ]0 and [MZA ]0 = 1.63 [MTA ]0 . We have found that there is a limit to the mass of the average cluster, which is able to virialize; its value is {MVIR}MAX = 8.1 × 1014 M¿. As expected, we found that shells present null proper acceleration at redshift values that are smaller than 0.755.
Conclusions. We have noticed that the cosmological constant imposes an upper limit for the mass enclosed by shells, which are able to reach zero proper velocity. Hence, this mass is the maximum mass of the virialized core, {MVIR}MAX. For the average cluster addressed in this work, the value is 2.34 times the mass of the virialized core at present. Shells enclosing masses M > {MVIR}MAX achieve zero proper acceleration and speed up, moving away from the virialized core, and never reach a turn-around point. Shells with M » {MVIR}MAX show zero proper aceleration at redshifts close to that at which the universe background acceleration is null. Finally, we have found that the relation between shell proper velocities and their radii can be adjusted by a straight line at z = 0 and from approximately 20 up to 40 Mpc; however, this line does not intercept the origin as velocities due to the Hubble flux do.
000048157 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
000048157 590__ $$a4.378$$b2014
000048157 591__ $$aASTRONOMY & ASTROPHYSICS$$b14 / 60 = 0.233$$c2014$$dQ1$$eT1
000048157 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000048157 700__ $$0(orcid)0000-0002-4303-9525$$aFernández-Pacheco, A.$$uUniversidad de Zaragoza
000048157 7102_ $$12004$$2038$$aUniversidad de Zaragoza$$bDepartamento de Física Teórica$$cAstronomía y astrofísica
000048157 7102_ $$12004$$2398$$aUniversidad de Zaragoza$$bDepartamento de Física Teórica$$cFísica de la Tierra
000048157 773__ $$g567 (2014), A37 [13 pp.]$$pAstron. astrophys.$$tASTRONOMY & ASTROPHYSICS$$x0004-6361
000048157 8564_ $$s723030$$uhttp://zaguan.unizar.es/record/48157/files/texto_completo.pdf$$yVersión publicada
000048157 8564_ $$s108639$$uhttp://zaguan.unizar.es/record/48157/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000048157 909CO $$ooai:zaguan.unizar.es:48157$$particulos$$pdriver
000048157 951__ $$a2017-06-12-09:55:28
000048157 980__ $$aARTICLE