1. 1 Origin and Evolution of Structure and Streaming Flows in the Local Group Grant J. Mathews Center for Astrophysics/JINA University of Notre Dame X. Zhao Department of Astronomy & Astrophysics Penn State University 3 rd Subaru Int. Conf. GALACTIC ARCHAEOLOGY Shuzenji, Japan Nov. 3, 2011

2. The Galaxy & the Local Group The Galaxy did not form in isolation. It is the product of the development of much larger structure. It was formed in concert with the entire Local Group and was affected by dark matter, dark energy, mergers, star formation and nucleosynthesis processes, mass ejection, heating, and cooling occurring throughout a large volume. 2

3. The Simulations 3 X. Zhao & GJM, PRD (2011) http://www.nd.edu/~xzhao/ CMB  LSS  Local Group

4. Initial conditions 4 CMBFAST  CMB power spectrum  Use power spectrum to generate a spectrum of random Gaussian fluctuations WMAP Cosmic Microwave Background Z ~ 1100 Z ~ 49

5. The Simulation 5 Large Scale Structure Simulation Local Group no GADGET SPH Hydro yes Gravity N-body Heating/ Cooling Star Formation Stellar Wind Mass ejection Nucleosnthesis Heating

6. 6 X. Zhao & GJM (2011) Begin with LSS

7. Large Scale Structure Simulations X. Zhao & GJM (2011 ) Scan for Poor Clusters

8. Local Group Galaxies 1 distance diameter luminosity type _____________________________________________ 2Milky Way - 100,000 14,000 spiral 3Sagittarius 78,000 15,000 30 elliptical 4 LMC 160,000 30,000 2,000 irregular 5SMC 190,000 20,000 250 irregular 6 Ursa Minor 225,000 1,000 0.3 elliptical 7 Draco 248,000 500 0.3 elliptical 8Sculptor 250,000 1,000 1.5 elliptical 9Carina 280,000 500 0.4 elliptical 10 Sextans 290,000 1,000 0.8 elliptical 11Fornax 430,000 3,000 20 elliptical 12 Leo II 750,000 500 1 elliptical 13 Leo I 880,000 1,000 10 elliptical 14Phoenix 1,270,000 1,000 0.8 irregular 15 NGC6822 1,750,000 8,000 300 irregular 16 And II 1,910,000 2,000 5 elliptical 17 NGC147 1,920,000 10,000 80 elliptical 18 NGC185 2,000,000 6,000 110 elliptical 19Andromeda 2,500,000 150,000 40,000 spiral 20 M32 2,500,000 5,000 300 elliptical 21NGC205 2,500,000 10,000 250 elliptical 22M33 2,500,000 40,000 4,000 spiral 23 IC1613 2,500,000 12,000 80 irregular 24 LGS 3 2,500,000 1,000 0.6 irregular 8 distance diameter luminosity type _____________________________________________ 25And I 2,570,000 2,000 5 elliptical 26 And III 2,570,000 3,000 1 elliptical 27 EGB0427+63 2,600,000 1,000 0.8 elliptical 28 Tucana 2,900,000 500 0.6 elliptical 29WLM 3,000,000 7,000 30 irregular 30 SagDIG 3,700,000 5,000 2 irregular 31 IC10 4,000,000 6,000 1,000 irregular 32 Pegasus 5,800,000 7,000 50 irregular ___________________________________________________________ distance and diameter are in light-years luminosity is in millions of Suns

9. Local Group Simulations 9 Dark Matter

10. Galaxies form in Dark Matter Potentials 10

11. 11 Galaxies

12. Disk Galaxies 12

13. A Milky Way Like Galaxy 13

14. 14 Results of Simulations: Significant star formation occurs far from the galaxy in protogalactic structures. Dwarf Proto-galactic halos arrive in a stochastic stream flowing along dark-matter filaments. The local-group like system shows an alignment defined by the directions of the streaming flows

15. Simulation Comoving Velocity Flow 15 Zhao & Mathews (2011)

16. Is there evidence for aligned flow in the Local Group? 16

17. High Velocity Clouds 17 B. Wakker et al. (1999)

18. Observed Local Group Radial motion 18 -1.5 Mpc +1.5 Mpc 0.0 Need to analyze extended Local Group Redshift distribution Goslowski et al 2006

19. 19 http://www.astro.utu.fi/EG/ELG/

20. 20 Conclusions Galaxies are not isolated objects but are the culmination of halo formation, mergers, star formation and nucleosynthesis in an extended connected environment. Significant star formation and occurs far from the galaxy in aligned dwarf proto-galactic structures. Dwarf Proto-galactic halos arrive in a stochastic stream flowing along dark-matter filaments. There is marginal evidence for alignment and streaming motion in the Extended Local Group