1.  Density and temperature conspire to have higher ionization species peak at higher radii (below); this qualitative behavior is seen for all feedback models and mass ranges  details will depend on UV background The Simulated Circumgalactic Medium at z ∼ 2 Molly S. Peeples (CGE Fellow; UCLA) with Ben Oppenheimer, Romeel Davé, Amanda Ford, Sean Fillingham, Juna Kollmeier The Dynamic Nature of Baryons; Leiden, August 2012 Stay tuned to an arXiv near you for upcoming papers… Wind ModelWind velocity v w Mass-loading factor η w Fiducial: momentum-driven scaling v w = [150 km/s] / σ gal η w ∝ σ gal -1 Mixed: v -2 energy-driven scaling for dwarfs v w = [150 km/s] / σ gal σ gal > 75 km/s: η w ∝ σ gal -1 σ gal < 75 km/s: η w ∝ σ gal -2 constant windv w = 680 km/sη w = 2 The Simulations  32 h -1 Mpc comoving cosmological 512 3 particle SPH simulations evolved with Gadget-2  Updated versions from Oppenheimer et al. (2010)  Wiersma et al. (2009) cooling; Haardt & Madau UV background  Compare effects of three star-formation driven wind scalings  Everything shown here is at z=2.2 z=2.2 star formation rate – stellar mass relation z=2.2 mass- metallicity relation ❷ The z=2.2 circumgalactic medium: physical properties ❶ Bulk galaxy properties  Steeper wind scaling ➜ shallower low-end mass function (left), steeper mass-metallicity relation (right); very little effect on star formation rates at fixed stellar mass (middle)  Simulated star formation rates (middle) still well below those inferred from observations; see Davé (2008), Narayanan & Davé (2012) for more thorough discussions  Feedback efficiency affects metal content of the ISM (right); is the metal content of the CGM another observable consequence? How do different models of star-formation driven winds affect the circumgalactic medium at z ∼ 2? ❶ Bulk galaxy properties ❷ The physical circumgalactic medium ❸ The observable circumgalactic medium ❸ The observable z=2.2 circumgalactic medium  Most absorption is saturated even out to large impact parameters (e.g., left, for OVI absorption around a M ★ ~10 10 galaxy in the fiducial simulation).  Stacking over multiple sightlines (below) leads to ① broader profiles than typically seen in individual spectra and ② not-as-black spectra. These effects will both be compounded with observation noise + resolution added.  Comparing at fixed stellar mass (right) allows for fairer comparison to observations: model galaxies will have made roughly the same amount of metals, so testing density of halos they live in, and where they have distributed their metals. log M ★ =10 1 Mpc/h comoving ~ 446 kpc physical 300 km/s deep projections Transmitted OVI flux z=2.2 halo mass – stellar mass relation  Feedback processes affect densities, temperatures, and metallicities. Left: mean stacks of 50 matched galaxies with M halo = 10 11 M ☀  3-d profiles show detailed differences (middle); fast winds ➜ higher temperatures; metallicity profiles show strong slope differences Fiducial Constant Mixed  Do column density profiles measured from spectra (left) agree with the intrinsic column density profiles (right)?