On the inside-out reionization of the MW satellite system - PowerPoint PPT Presentation

On the inside-out reionization of the MW satellite system Reionization at galaxy-scale P . Ocvirk, D. Aubert Observatoire astronomique de Strasbourg Impact of radiation field structure on the Galaxy RT simulations, reionization history of the MW satellites Pierre OCVIRK - CRTCRPW - Austin 2012

Reionization & the Milky Way Bootes D = 60 kpc UV background r h = 220 pc M v = -5.8 mag => gas photo-evaporation and SDSS collaboration V. Belokurov => suppression of low-mass galaxies => satellite galaxies, ultra-faint dwarfs Courtesy z reion =5 100 MW Satellites LF Semi-analytical models Satellite SF stops at z reion N(<M v ) 10 => sats = reionization fossils z reion =12 reionization uniform & instantaneous z reion = 5 z reion = 8 z reion = 12 Busha et al. 2010 1 0 0 − 5 − 5 − 10 − 10 − 15 − 15 M v Pierre OCVIRK - CRTCPW - Austin 2012

Impact of local structure of UV field at reionization on MW satellite pop cumulative normalized radial distribution of Milky Way satellites UV External, uniform BG Internal, inside-out SAM based on Via Lactea II photo-evaporation recipes from Iliev et al. 2006 => Signature of reionisation geometry survives down to z=0 z=0 Simplification: unique central UV source -_- Ocvirk & Aubert 2011 Pierre OCVIRK - CRTCPW - Austin 2012

Comparing with literature This work Maccio et al. 2010 Koposov et al. 2009 Busha et al. 2010 Lunnan et al. 2011, “self-consistent” reionisation Munoz et al. 2009 Pierre OCVIRK - CRTCPW - Austin 2012

Impact of local structure of UV field at reionization on MW satellite pop cumulative normalized radial distribution of Milky Way satellites UV External, uniform BG Internal, inside-out SAM based on Via Lactea II photo-evaporation recipes from Iliev et al. 2006 => Signature of reionisation geometry survives down to z=0 z=0 Simplification: unique central UV source -_- Ocvirk & Aubert 2011 Pierre OCVIRK - CRTCPW - Austin 2012

PICON PICON: P hoto- I onization of CON strained realizations of the local group Radiative post-processing of high-res hydro simulation of local group formation HYDRO SIMULATION RADIATIVE TRANSFER o CLUES 1 o ATON (Aubert & Teyssier 2008) o Gottloeber et al. 2010 o grid-based method o GADGET 2, WMAP3 (no live RT) o multi-GPU: CUDATON o produces realistic MW+M31+M33 o Stellar sources T=50000 K, f esc =0.2 o M part =2.10 5 M ☉ (in HR region) o H only chemistry, 1 photon group o ~20 h -1 kpc resolution, 512 3 , 11 h-1 Mpc box o No photo-evaporation/feedback!! 1 CLUES: Constrained Local UniversE Simulations Y. Hoffman (Racah Institute of Physics) o No external source (Virgo) G. Yepes (Universidad Autonoma de Madrid) S. Gottloeber (Leibnitz Institut fuer Astrophysik Potsdam) Pierre OCVIRK - CRTCPW - Austin 2012

Post-processing of the CLUES simulation with ATON Setup geometry o Low res region => ρ =10 -2 ρ c o Box :11 h -1 Mpc @512^3 MW o => ~20 h -1 kpc resolution Boundary conditions M31 o Transmissive (photons get out) o No external source (internal reionization) M33 <x neutral > ρ at z=9 11 h -1 Mpc Pierre OCVIRK - CRTCPW - Austin 2012

Local group reionization map o Slice through MW-M31-M33 plane 200kpc thickness MW o 2-4 major patches o patches more or less structured o each galaxy reionizes in isolation M31 o Is that always so? Ocvirk et al. 2012, submitted Pierre OCVIRK - CRTCPW - Austin 2012

Impact of source modelling Increasing emissivity Mt=5.10 6 M ☉ Mpc) Mpc) Mpc) z’ (h z’ (h z’ (h No feedback (halo detection Increasing feedback strength limit) x’ (h Mpc) x’ (h Mpc) x’ (h Mpc) <z > <z > <z > 6 7 8 9 10 11 12 13 14 15 16 6 7 8 9 10 11 12 13 14 15 16 6 7 8 9 10 11 12 13 14 15 16 Lyman-Werner T vir ~10 4 K suppression of Mt~1.10 8 M ☉ running todo todo H 2 formation (z-dependent) (Shapiro et al.) Strong SN Mpc) Mpc) Mt=1.10 9 M ☉ feedback z’ (h z’ (h todo (ref?) x’ (h Mpc) x’ (h Mpc) <z > <z > z reion 6 7 8 9 10 11 12 13 14 15 16 6 7 8 9 10 11 12 13 14 15 16 Pierre OCVIRK - CRTCPW - Austin 2012

Conclusions I o MW and M31 reionize in isolation except in the most extreme models (Strong SN feedback + high emissivity) MW o => modelling isolated MWs should be mostly ok in SAMs (cf Griffen et al. 2012) o low emissivity models => large Δ z reion o => effect on global satellite reionization M31 history? o Effect of > 12.7 Gyr dynamical evolution? Pierre OCVIRK - CRTCPW - Austin 2012