The High Redshift Universe Next Door Josh Simon Carnegie Observatories

Things I Work On Galaxy kinematics Dark matter Milky Way satellites and streams HII regions/chemical evolution Dwarf galaxies Supernovae Metal-poor stars

Pop Quiz, Hotshot Is your primary research (a) observational (b) theoretical (c) don’t know If you answered (b) or (c), please skip to the last question

Pop Quiz, Hotshot 2. At what wavelengths do you observe? (a) gamma-ray (b) X-ray (c) UV (d) optical (e) IR (f) radio

Pop Quiz, Hotshot 3. Are the objects you observe (a) pretty close (solar system) (b) far away (Galactic) (c) really far away (extragalactic) (d) really, really far away (cosmological) .

Pop Quiz, Hotshot 4. What is your favorite color? (a) Red. (b) Orange. (c) Green. (d) Blue. No, yellow!

Outline I. Formation histories of Local Group dwarfs a) What were the properties of the first stars and galaxies? b) What role did the dwarfs play in the buildup of the Milky Way halo? c) What distinguishes dwarfs from globular clusters? II. Kinematics of dwarf galaxies a) What is their dark matter content? b) What is the nature of dark matter?

A Whole New Local Group 2011: 27 (!) Milky Way satellite galaxies New dwarfs up to 600 times fainter than any previously known galaxies (Willman et al., Zucker et al., Belokurov et al.) globular clusters tidal stream new dwarf Belokurov et al. (2006a)

Why Study Nearby Galaxies? Oesch et al. (2009) Belokurov et al. (2006b)

Why Study Nearby Galaxies? Oesch et al. (2009) Belokurov et al. (2006b) 1/r2 at z=7: 2  10-59 1/r2 at 100 kpc: 1  10-47

Spectroscopic Surveys of Dwarfs Metallicity distribution functions Dwarf galaxy evolution and the formation of the halo Chemical abundance patterns as a function of metallicity Search for the most metal-poor stars Nucleosynthesis and chemical evolution in the early universe

Spectroscopic Surveys of Dwarfs Gas outflow (and infall) needed to explain MDFs MDFs depend on luminosity Kirby et al. (2011)

Luminosity-Metallicity Relation Faint dwarfs ≠ tidally-stripped bright dwarfs Stars know what luminosity system they live in Progress needed: How do we match these dwarfs to subhalos in simulations? Kirby et al. (2011)

Universal Early Chemical Evolution? [Mg/Fe] [Ti/Fe] [Ca/Fe] [Cr/Fe] MV = -20.5 MV = -11.1 MV = -6.6 MV = -6.3 MV = -5.7 MV = -3.9 MV = -3.8 . Collaboration opportunity: Compare abundance patterns to high-z Ly-a systems? Frebel et al. (2010) Simon et al. (2010)

Search for the First Stars in Dwarfs

2000 Stars in Sculptor

2000 Stars in Sculptor [Fe/H] ~ -3.1 [Fe/H] = -3.8 [Fe/H] ~ -3.8 A star? M dwarf?

The Nature of Dark Matter The missing satellite problem ? Belokurov et al. (2006a) Springel et al. (2001) Progress needed: (1) More/deeper searches for dwarfs (2) Larger spectroscopic surveys of kinematics (3) Understanding observation-simulation comparison

The Nature of Dark Matter Indirect detection of dark matter Fermi Space Telescope Ursa Minor Segue 1 Strigari et al. (2008) Martinez et al. (2009) Simon et al. (2010)

The Nature of Dark Matter The density profiles of dark matter halos cusp/core 1 2 Radial velocities only Strigari et al. (2007) d(r2) dr Jeans equation: r = —  r — 2(r)r2 GM(r)

The Nature of Dark Matter The density profiles of dark matter halos cusp/core 1 2 GMT/TMT proper motions Radial velocities only Strigari et al. (2007) d(r2) dr Jeans equation: r = —  r GM(r) — 2(r)r2

Other Projects How are heavy elements distributed through galaxies? What are the progenitors of Type Ia SNe? What is the effect of a low-metallicity environment on star formation and gas tracers?

Opportunities for Collaboration Observational: stellar kinematics of Local Group dwarfs Theoretical: understanding the matching between real dwarfs and simulated subhalos Theoretical: predictions for observable effects of dark subhalos on tidal streams

New Opportunity for Students http://obs.carnegiescience.edu/gradfellowships

Summary Local Group dwarfs are unique laboratories for Dark matter - missing satellites, indirect detection, dark matter density profiles Early galaxy formation – first stars, chemical evolution Come talk to me about: Comparisons between observations and N-body simulations Spectroscopic surveys in the Local Group Observational tests of dark matter models Predicted properties of first stars and SNe