1 / 55

First galaxies and reionization of the Universe: current status and problems

First galaxies and reionization of the Universe: current status and problems. A. Doroshkevich Astro-Space Center, FIAN, Moscow. Theoretical expectations and observational problems. Scientific activity: >17 publications in 2012

elaine-wade
Download Presentation

First galaxies and reionization of the Universe: current status and problems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. First galaxies and reionization of the Universe: current status and problems A. Doroshkevich Astro-Space Center, FIAN, Moscow.

  2. Theoretical expectations and observational problems • Scientific activity: >17 publications in 2012 • z~25 – 10 - formation of the first stars • and ionizing bubbles • Bubble model, UV-background, • non homogeneities in xH and Tg • z~ 10 WMAP: τT~0.1, xH=nH/nb << 1 • z~6.5 – 5 - high ionization, xH~10-3 • z< 3 - xH~10-5 • 1. We do not see any manifestations of the first stars • 2. We do not know the main sources of ionizing UV radiation

  3. Universe Today 12.12.2012

  4. Possible sources of ionizing UV background 1. exotic sources – antimatter, unstable particles, etc… 2. First stars Pop III with Zmet<10-5 Z¤ or 3. non thermal sources - AGNs and Black Holes 4. Quasars at z < 3.5, He III

  5. Reionisation • Θ(z)=α(T)n(z)H(z)~3T4-0.7z103/2, T4~2. • For z10>1 recombination becomes important ! Thermal sources:E~7MeV/baryon, Nγ< 5 105/baryon Non thermal sources - AGNs and Black Hole E~ 50MeV/baryon, Nγ~3.5 106/baryon • fesc~ 0.1 - 0.02, Nbγ~1 - 2 Ωmet~2 10-6Ωbar~8 10-8, Ωbh~3 10-7Ωbar~ 10-8 In reality both sources are important.

  6. Spitzer photometry Z~8, 63 candidats, 20 actually detected SMD for M<-18 ρ*(z=8)~106Ms/Mpc3 Ω*(z=8)~0.4 10-5 Ωmet(z=8)~0.4 10-7 Ωreio~10-7 – 10-8 Labbe I., 2010,ApJ.,708,L26, 1209.3037 z~2.5, Ωmet~2.3 10-6 for IGM, Ωmet~3 10-5 for galaxies

  7. Universe Today 1211.6804

  8. Ellis et al. arXiv1211.6804

  9. 1. Formation of the virialized relaxed massive DM cloud (perhaps, anisotropic) at z<zrec~103with ρcl ~200<ρ(z)> and overdensity δDM~104 z107M91/2 2. Cooling and dissipative compression of the baryonic component, but the bulk motions and the kinetic temperature of stars are preserved 3. Formation of stars – luminous matter with M>MJ Main Problem of the star formation MJ/M¤~2·107T43/2nb-1/2, For stars: T4~10-2, nb>102cm-3 , MJ/M¤<103 z=zrec,T4~0.3, nb~250 cm-3, MJ/M¤~2·105 Parameters of baryonic components <ρbar>~4·10-28z103g/cm3, <ρgal>~10-24g/cm3, <ρstar>~1 g/cm3, ρBH~2 M8-2g/cm3 Cooling factors: H2 molecules and metals (dust, C I etc.) Three steps of galaxy formation

  10. Simulations (2001) • The box ~1Mpc, 128 -256 cells, • Ndm~107, mdm~30M0, Mgal~106 – 107 M0 • Very useful general presentation • (the galaxy and star formation are possible) • Restrictions: • a. small box → random regions (void or wall) & unknown small representativity • b. large mass DM particles in comparison with the mass of stars.

  11. What is mostly interesting • a. realization – it is possible! • b. wide statistics of objects -- what is possible for various redshifts • c. rough characteristics of internal structure of the first galaxies • d. general quantitative analysis of main physical processes

  12. Density – temperature 2001

  13. M~5 105Ms T4~0.3 nb~10cm-3 fH2~3 10-5 j21~1 MJ(25)~104Ms MJ(20)~500Ms Lazy evolution, Monolitic object Monotonic growth ρ(z)??? Instabilities! Machacek et el. 2001, ApJ, 548, 509

  14. Formation of massive galaxies owing to the merging of low mass galaxies. ρ, T & Z, Wise 1011.2632

  15. Influence of the LW background • Actual limit is JLW21~1 – 0.1 for various redshifts • For the period of full ionization z~10 we get • JLW 21~4 Nbγ • This means that at at 10>z>8.5 • the H2 molecules are practically destroyed and star formation is strongly suppressed • This background is mainly disappeared at z~8.5

  16. Corrections for both limits ~10 times J21~4Nbγ Safranek-Shrader, 1205.3835

  17. UV-background from BH accretion • T4~1 – 4, for sources with Eg~10eV and Eg~50eV. and depends upon cooling factors (radiative and expansion) Elvert: • In the case we can use

  18. New semi analytical approachWe know the process of the DM halo formation and can use this information • Assumptions: • a.what is the moment of halo formation • b. baryons follow to DM and have the same • pressure and kinetic temperature • c. what is the cooling of the baryonic • components • d. thermal instability leads to formation of • stars with masses Mst > MJeans

  19. Two steps of the DM halo formation We consider the homogeneous ball with mass M=109Mo M9 within the expanded Universe. Its evolution can be described analytically up to the collapse at 1+z=10zf and subsequent relaxation. In the case we have for the NFW profiles two parametric description: ρDM~10-23g/cm3M91/2zf10, TDM~40eV M95/6zf10/3mDM/mb and all other characteristics. Physical model

  20. Analytical characteristics for DM component • For the NFW halo with the virial • mass M=109 M9 Ms formed at zf=(1+z)/10 • Within central core with r< rs we have • ρDM~10-23g/cm3M91/2zf10, TDM~40eV M95/6zf10/3mDM/mb • Cooling factors: H2 and atomic for T4>1, • Three regimes of the gas evolution – • slack, rapid and isothermal • Thermal instability and the core formation • Stars are formed for Tbar<100K and nbar>100cm-3 • with Mstar > MJ ~5 107T43/2/nbar1/2Ms

  21. Formation of the first stars with Mcl/M0 = 3 105 and 7 105, zf=24 (left) and Mcl/M0=0.7 108 and 3 108, zf=11 (right)

  22. Low mass limit for the rapid-lazy formation of the first galaies

  23. Behroozi et al., 1207.6105 Stellar mass vs. host halosSmall fraction of stars

  24. SMF~Mh-4/3, M>Mch; SMF~Mh2/3, M<Mch (left panel) Ms/Mh<2 – 3% at all z! ?continual evolution? Behroozi et al., 1209.3013 - SFR(Mh)

  25. Stars occupy very small matter fraction ? Low massive objects dominate at all redshifts? Is this impact of nature or selection effect? Formation of the massive galaxies owing to the merging of satellites with stars?? Illingworth 1977 for 13 E-galaxies Fraction of massive objects increases more rapidly – merging of satellites or other factors?? Small scale perturbations and missing satellite problem – when and where had been formed dwarf galaxies. comments

  26. ρDM~10-23g/cm3M91/2zf10, TDM~40eV M95/6zf10/3mDM/mb rs=2.3M131/6/zf10/3kpc=0.16M61/6/zf10/3kpc Zf=0.55σv0.1/rs1/4≈0.27M13-0.1≈1.33M6-0.1 Problems of the measurements – T(r) and dynamical masses, finally: rs~M61/2, T~M61/2 Physical model

  27. 10 clusters of galaxies Pointecouteau et al., A&A,435, 1, 2005 ,Pratt et al., A&A 446,429 name z R +/- T +/- M13 +/- M/TR 1+z Mpc keV 10^13M_o A1983 0.0442 0.717 0.110 2.2 0.1 10.90 0.34 0.95E+00 2.05 A2717 0.0498 0.668 0.076 2.6 0.1 8.80 0.23 0.70E+00 2.27 MKW9 0.0382 0.717 0.036 2.4 0.2 11.00 0.11 0.86E+00 2.11 A1991 0.0586 0.737 0.034 2.7 0.1 12.00 0.10 0.82E+00 2.13 A2597 0.0852 0.897 0.032 3.7 0.1 22.20 0.10 0.92E+00 2.00 A1068 0.1375 1.060 0.025 4.7 0.1 38.70 0.07 0.11E+01 1.88 A1413 0.1430 1.129 0.029 6.6 0.1 48.20 0.09 0.88E+00 1.97 A478 0.0881 1.348 0.047 7.1 0.1 75.70 0.15 0.11E+01 1.79 PKS 0745 0.1028 1.323 0.034 8.0 0.3 72.70 0.10 0.94E+00 1.88 A2204 0.1523 1.365 0.032 8.3 0.2 83.90 0.10 0.10E+01 1.83 mns 0.92E+00 sig 0.11E+00

  28. Walker et. al, 2009, ApJ, 704, 1274 - 28 objects name sig_v +/- Mhalf +/- <rho> +/- M*zf^10 z_f +/- km/s 10^6M_o M_o/pc^3 Carina 6.60 1.20 3.40 1.40 0.320 0.120 0.18 0.12E01 0.53Draco 9.10 1.20 11.00 3.00 0.230 0.060 0.23 0.11E01 0.32Fornax 11.70 0.90 27.00 0.50 0.160 0.030 0.25 0.99E00 0.04LeoI 9.20 1.40 6.50 2.10 0.660 0.210 0.50 0.12E01 0.44LeoII 6.60 0.70 3.10 0.90 0.400 0.120 0.21 0.12E01 0.39Sculptor 9.20 1.10 4.60 1.70 1.300 0.500 0.83 0.13E01 0.55Sextant 7.90 1.30 11.00 4.00 0.100 0.030 0.99 0.99E00 0.39UMi 9.50 1.20 7.80 2.20 0.550 0.150 0.46 0.12E01 0.37CVen I 7.60 0.40 19.00 2.00 0.025 0.003 0.32 0.84E00 0.10Coma 4.60 0.80 0.90 0.35 0.490 0.180 0.14 0.13E01 0.56Hercules 3.70 0.90 2.60 1.40 0.017 0.009 0.82 0.89E00 0.53 Leo T 7.50 1.60 5.80 2.80 0.250 0.120 0.18 0.11E01 0.59Segue 1 4.30 1.20 0.31 0.19 3.010 0.800 0.50 0.17E01 1.06UMa I 11.90 3.50 26.10 6.00 0.200 0.120 0.30 0.10E01 0.29UMa II 5.70 1.40 2.60 1.40 0.230 0.120 0.11 0.12E01 0.68AndII 9.30 2.70 62.00 36.00 0.008 0.005 0.19 0.71E01 0.45Cetus 17.00 2.00 99.00 23.00 0.110 0.020 0.32 0.90E00 0.22Sgr^c 11.40 0.70 120.00 60.00 0.008 0.001 0.24 0.68E00 0.35Tucana 15.80 3.60 40.00 19.00 0.460 0.220 0.86E 0.11E01 0.57Bootes 1 6.50 2.00 5.90 3.70 0.100 0.060 0.73E 0.10E01 0.70Cven II 4.60 1.00 0.90 0.40 0.530 0.250 0.15E 0.13E01 0.65Leo IV 3.30 1.70 0.73 0.73 0.110 0.110 0.28E 0.11E01 1.26Leo V 2.40 1.90 0.14 0.14 0.450 0.450 0.51E 0.14E01 1.57Segue 2 3.40 1.80 0.23 0.23 1.310 0.300 0.19E 0.16E01 1.59AndIX 6.80 2.50 14.00 11.00 0.023 0.017 0.26E 0.84E00 0.73AndXV 11.00 6.00 19.00 2.00 0.230 0.250 0.30E 0.10E01 0.22mns 0.23Esig 0.23E

  29. zf & zfM60.1 for 28 dSph galaxies

  30. The end The end

  31. Behroosi et al. 1209.3013

  32. Comments • Importance – instead of the experiment • Complexity, representativity and precision (WMAP). • Modern facilities • Our attempts – simulations versus analysis

  33. Cooling functions.

  34. Smith, B.,2008, MNRAS, 385, 1443

  35. W=GM2/Rvir~3·1055z10M95/3erg ESN~1052 – 1055erg Dex<0.2 – 0.5 Mpc- IGMimpact For M9>0.1 we have SN metal enrichment within galaxy, otherwise – matter ejection Low massive stars, satellites and merging SN explosions

  36. Bradley L., 1204.3641, UV luminosity function for z~8 • Low massive objects dominate • Why? • Is this selection effect? • What about object collections? suppression of object formation ? • What is at z=9? 10?

  37. Observations of the Milky Way satellites with different corrections Tollerud et al. 2008, ApJ, 688, 277

  38. 16 observed dSph galaxies(Walker et al.2009)dominated by DM component • DM parameters • ρ~0.07M61/2f3(M6) • P~37f4(M6) • S~14M60.83/f(M6) • Z10=0.9M6-0.1 • Bovill & Ricotti, • 2009, ApJ, 693,1859 • Tollerud et al. 2008

  39. Conclusions • We do not see any manifestations of the first stars • We do not know the main sources of ionizing UV radiation • A. It seems that first stars Pop II & III , SNs, GRBs are approximately effective (~30 – 40%) • B. non thermal sources BHs remnants and/or AGNs are more effective (~50% + ?) • C. We can semi analytically describe the formation and evolution of the first galaxies

  40. Galaxies and BHs BHs are observed in~1% of all galaxies, n~10-4Mpc-3 • Very massive BHs are observed as QSRs with • Nqsr~10-5 – 10-6 Mpc-3 at z<5; mainly at z~2 – 2.5 • Perhaps, there are AGNs in 70% of old massive galaxies. • ρBH~3 10-2M9-2g/cm3, • ρDM~10-23zf10M90.5g/cm3 withinhalo

  41. Vestergaard et al. 2008

  42. BH-distributions: M(z) & L/LedVestergaard, Osmer, 2009, ApJ,699,800

  43. Number density of the SMBH,Kelly et al., 2011, 1006.3561

  44. 1. We see rare supermassive BH at z<2 - early formation and short lifetime. 2. Impact of the accretion rate. 3. Are the SMBH primordial? 4. van den Bosch, Nature, arXiv:1211.6429 NGC 1277, M~1.2 1011M☼, MBH~1.7 1010M☼ 5. Nature: Simcoe et al., 2012, QSR ULASJ120+064, z=7.08, Zmet< 10-4Z☼ BH evolution

  45. SMBH formation • Accretion of baryons from a thin/thick or HMD disk,major or minor mergers, from Pop III BH remnants(Shapiro 2005). • Problems: small mass of remnants (<103M☼) • For the observed SMBHs MBH~(105 – 1010)M☼ • The expected mass amplification is (103 – 104). • Primordial BH(Ricotti et al. 2007, Duching 2008)

  46. Three scenario of the BH formation

  47. Two processes of the H2 formation H+e=H-+γ, H-+H=H2+e, γ~1.6eV H+p=H2+ +γ, H2++H=H2+p Epar=128K, Eort=512K In both case the reaction rate and the H2 concentrations are proportional to <ne>=<np> At 1000>z>zrei xe=ne/<n>~10-3what is very small value. Feedback of LW radiation 912A<λ<1216A H2+γLW =2H Simplest problem – first galaxies and POP III stars

  48. Redshift variations of intensity of the UV background

  49. SMGs, Yun et al., 1109.6286

  50. Gonzalez V., 2011, ApJ, 735, L34

More Related