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Cosmological constraints from estimates of M gas -M tot -c in X-ray luminous clusters

Cosmological constraints from estimates of M gas -M tot -c in X-ray luminous clusters. S. Ettori (INAF/OA Bologna) with F. Gastaldello, M. Meneghetti, I. Balestra, S. Borgani, S. Molendi, P. Tozzi et al. Potsdam, September 23, 2009: cosmological constraints from X-ray luminous clusters.

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Cosmological constraints from estimates of M gas -M tot -c in X-ray luminous clusters

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  1. Cosmological constraints from estimates of Mgas-Mtot-c in X-ray luminous clusters S. Ettori (INAF/OA Bologna) with F. Gastaldello, M. Meneghetti, I. Balestra, S. Borgani, S. Molendi, P. Tozzi et al. Potsdam, September 23, 2009: cosmological constraints from X-ray luminous clusters

  2. Outline • How good are the estimates of Mgas , Mtot , c: results from hydrodynamical simulations • Clusters as cosmological probes: uncertainties are in the outskirts • Concentration – Mtot relation & fgas: a new approach to constrain σ8 & Ωm

  3. X-ray vs lensing mass: simulations Hydrodynamical simulations of 3 massive clusters (0.7-1.1e15 Msun). Analyzed after convolution with X-ray (XMAS) and lensing (SkyLens) exposures. Meneghetti et al. 09 subm

  4. X-ray vs lensing mass: simulations XMAS SkyLens Meneghetti et al. 09 subm

  5. X-ray total & gas mass Mgas whatever the projection/method is Mgas is recovered within few (~5) % Mtot MX vs Mtrue: -12 (rms: 5) % ML vs Mtrue: 2 (rms: 16) %

  6. X-ray vs lensing mass: simulations Concentration from fitting a NFW profile • Considering only the projection of g1 & g72: • c from X-ray analysis: biased low by 10-20 (rms 13) % • c from W only: +88 (rms 50) %, S only +12 (38) % • c from W+S lensing: good agreement (rms 14) %

  7. Gas mass fraction To constrain the cosmological model Ωm +Ω+Ωk =1 We combine a dynamical and a geometricalmethod (see also Allen et al, Blanchard et al., Ettori et al, Mohr et al) : • baryonic content of galaxy clusters is representative of the cosmic baryon fraction Ωb / Ωm(White et al. 93) • fgas is assumed constant in cosmic time in very massive systems (Sasaki 96, Pen 97)

  8. X-ray total mass Total mass from X-ray is determined by assuming 1. spherical symmetry,2. hydrostatic equilibrium n~ -2/-2.4 T~ 0/-0.8

  9. An example: RXJ1252, z=1.235

  10. An example: RXJ1252, z=1.237 We fit a single absorbed MEKAL to measure Te(Rosati et al. 04). The deprojected Sb provides nethat is then fitted with a functional form. NOTE: 850 cts <35”, 1220 cts <59” (rc~10”, 250 cts)

  11. Systematics on Ωm- Ω -w assuming T(r) as observed in local systems (e.g. Vikhlinin et al. 06) WMAP-5 For details see Ettori et al. 09, arXiv:0904.2740

  12. Bkg: dominant in GCs outskirts Gal foreground Residual CXB Source Ins. background Simulation for 3keV cluster @ R200

  13. ICM at R200:Observed clusters Study of Sb at r >0.7 R200 in a sample of high-z (z>0.3) objects with CXO (Ettori & Balestra 09) fit of the derivative of ln(Sb)/ln( r): at 0.7 R200: -3.9 ± 0.7, at R200: -4.3 ± 0.9 A1795 with Suzaku by M.Bautz et al. : T ~ r -0.9, M500 ~20-30% < expected XMM (Leccardi & Molendi 08)

  14. On the Temperature profile Chandra XMM EDGE 1Msec arXiv:0707.4103

  15. On the Temperature profile Chandra XMM WFXT 50ksec

  16. The c-Mtot relation We (Ettori et al. 09 in prep) recover Mgas & Mtot from 44 X-ray luminous galaxy clusters observed with XMM-Newton in the z-range 0.1-0.3 (from Leccardi & Molendi 2008) to constrain (σ8, Ωm). We use 2 independent methods & check several systematics on Mtot

  17. The c-Mtot relation: σ8-Ωm Dotted lines: Eke et al. (01) for a given ΛCDM at z=0 (from top to bottom: σ8=0.9 and 0.7). Shaded regions: Maccio’ et al. (08, see Bullock et al. 01) for WMAP-1, 5 and 3 years (from the top to the bottom, respectively). Dashed lines (thin: z=0.1, thick: z=0.3) indicate the best-fit range at 1σ in a WMAP-5 yrs cosmology from Duffy et al. (08) z<0.150.15<z<0.25z>0.25

  18. The c-Mtot relation: σ8-Ωm • We constrain (σ8, Ωm) by comparing our estimates of (c200, M200) to the predictions tuned from CDM simulations (black contours) • We consider both systematics (e.g. different T profiles; fitted ngas; no-limits on rs; two methods: ~10%) in our measurements & scatter from numerical predictions (~20%, e.g. Neto et al. 07) • We add constraints from fbar (red contours). Eke et al. 01 σ8 = 0.94±0.25 Ωm=0.25+0.2-0.1 σ8 = 0.86±0.06 Ωm=0.28±0.01

  19. CONCLUSIONS on c–Mtot-fgas • X-ray techniques provide Mgas & Mtot with a good control of both statistical & systematic uncertainties • Aselection of relaxed, massive objects over a large z-rangecan constrain some cosmological parameters (σ8, Ωm, ΩΛ) through estimates in the c-Mtot-fgas plane • CAVEAT: N-body community ’d realize an adequate sets of cosmological simulations over a large box to properly predict the expected concentration associated to the massive (>1014 Msun) DM halos as function of (σ8, Ωm; z)

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