Local Group Time Machine #LGAstat

My talk on the near field-far field connection for dwarf galaxies at the Astrostatistics conference at the University of Michigan on June 4th, 2015.

Transcript

1. Dan Weisz Hubble Fellow University of Washington Collaborators: Mike Boylan-Kolchin (MBK) James Bullock Charlie Conroy Ben Johnson #LGAstat Michigan 6.4.2015 The Local Group as a Time Machine
2. (z~6-10) A Primary Goal of high-z galaxy studies (HUDF, JWST, FF): Find, count, & characterize galaxies during reionization Current Consensus: Cosmic Reionization is powered by Galaxies
3. −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 −1.31 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 Number Density MUV Brighter Fainter Less More Galaxy Ultra-Violet Luminosity Function at z~7 Finkelstein+ 2014
4. −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 −1.31 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 Number Density MUV Brighter Fainter Less More Galaxy Ultra-Violet Luminosity Function at z~7 Faint end Slope Finkelstein+ 2014
5. High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −21 −20 −19 −18 −17 lute UV Magnitude (1500 Å) z ∼ 4 y +14 urg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −21 −20 −19 −18 ute UV Magnitude (1500 Å) z ∼ 6 y 9 +07 +14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 4 This Study Bouwens+14 van der Burg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 6 This Study McLure+09 Willott+13 Bouwens+07 Bouwens+14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 ϕ (# Mag−1 Mpc−3) McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 +2.52 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 ϕ (# M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 −21 −20 −19 −18 te UV Magnitude (1500 Å) z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 ϕ* = 0.72 +2.52 −0.65 x10−4 Finkelstein et al. 2014 me UV Luminosity Function at z = 4–8 17 −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 4 -17 -16 -15 -14 -13 -12 -11 -10 10-1 100 101 102 103 Number Density MUV Brighter Fainter Less More Galaxy Ultra-Violet Luminosity Function at z~7
6. High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −21 −20 −19 −18 −17 lute UV Magnitude (1500 Å) z ∼ 4 y +14 urg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −21 −20 −19 −18 ute UV Magnitude (1500 Å) z ∼ 6 y 9 +07 +14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 4 This Study Bouwens+14 van der Burg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 6 This Study McLure+09 Willott+13 Bouwens+07 Bouwens+14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 ϕ (# Mag−1 Mpc−3) McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 +2.52 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 ϕ (# M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 −21 −20 −19 −18 te UV Magnitude (1500 Å) z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 ϕ* = 0.72 +2.52 −0.65 x10−4 Finkelstein et al. 2014 me UV Luminosity Function at z = 4–8 17 −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 4 -17 -16 -15 -14 -13 -12 -11 -10 10-1 100 101 102 103 Number Density MUV Brighter Fainter Less More Needed to maintain reionization Galaxy Ultra-Violet Luminosity Function at z~7 (e.g., Kuhlen+ 2012, Robertson+ 2013, 2015)
7. High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −21 −20 −19 −18 −17 lute UV Magnitude (1500 Å) z ∼ 4 y +14 urg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −21 −20 −19 −18 ute UV Magnitude (1500 Å) z ∼ 6 y 9 +07 +14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 4 This Study Bouwens+14 van der Burg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 6 This Study McLure+09 Willott+13 Bouwens+07 Bouwens+14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 ϕ (# Mag−1 Mpc−3) McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 +2.52 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 ϕ (# M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 −21 −20 −19 −18 te UV Magnitude (1500 Å) z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 ϕ* = 0.72 +2.52 −0.65 x10−4 Finkelstein et al. 2014 me UV Luminosity Function at z = 4–8 17 −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 4 -17 -16 -15 -14 -13 -12 -11 -10 10-1 100 101 102 103 Number Density MUV Brighter Fainter HUDF Less More Galaxy Ultra-Violet Luminosity Function at z~7 Needed to maintain reionization (e.g., Kuhlen+ 2012, Robertson+ 2013, 2015)
8. High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −21 −20 −19 −18 −17 lute UV Magnitude (1500 Å) z ∼ 4 y +14 urg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −21 −20 −19 −18 ute UV Magnitude (1500 Å) z ∼ 6 y 9 +07 +14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 4 This Study Bouwens+14 van der Burg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 6 This Study McLure+09 Willott+13 Bouwens+07 Bouwens+14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 ϕ (# Mag−1 Mpc−3) McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 +2.52 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 ϕ (# M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 −21 −20 −19 −18 te UV Magnitude (1500 Å) z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 ϕ* = 0.72 +2.52 −0.65 x10−4 Finkelstein et al. 2014 me UV Luminosity Function at z = 4–8 17 −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 4 -17 -16 -15 -14 -13 -12 -11 -10 10-1 100 101 102 103 Number Density MUV Brighter Fainter HUDF HST FF (5x, 10x) Less More Galaxy Ultra-Violet Luminosity Function at z~7 Needed to maintain reionization (e.g., Kuhlen+ 2012, Robertson+ 2013, 2015)
9. High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −21 −20 −19 −18 −17 lute UV Magnitude (1500 Å) z ∼ 4 y +14 urg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −21 −20 −19 −18 ute UV Magnitude (1500 Å) z ∼ 6 y 9 +07 +14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) CANDELS: The Rest-Frame UV Luminosity Function at z = 4–8 17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 4 This Study Bouwens+14 van der Burg+10 M* = −20.73+0.09 −0.09 α = −1.56+0.06 −0.05 ϕ* = 14.05 +2.05 −1.85 x10−4 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 6 This Study McLure+09 Willott+13 Bouwens+07 Bouwens+14 M* = −21.13+0.25 −0.31 α = −2.02+0.10 −0.10 ϕ* = 1.86 +0.94 −0.80 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 10−2 z ∼ 8 This Study Bouwens+14 Schmidt+14 Finkelstein et al. 2 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 ϕ (# Mag−1 Mpc−3) McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 +2.52 Finkelstein et al. 2014 High-redshift observations State-of-the-art in deep fields (HST) −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 ϕ (# M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 −21 −20 −19 −18 te UV Magnitude (1500 Å) z ∼ 8 13 4 1 M* = −20.89+0.74 −1.08 α = −2.36+0.54 −0.40 ϕ* = 0.72 +2.52 −0.65 x10−4 Finkelstein et al. 2014 me UV Luminosity Function at z = 4–8 17 −17 −23 −22 −21 −20 −19 −18 −17 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 5 This Study Bouwens+14 van der Burg+10 McLure+09 M* = −20.81+0.13 −0.12 α = −1.67+0.05 −0.06 ϕ* = 8.95 +1.92 −1.31 x10−4 −23 −22 −21 −20 −19 −18 Absolute UV Magnitude (1500 Å) 10−7 10−6 10−5 10−4 10−3 10−2 ϕ (# Mag−1 Mpc−3) z ∼ 7 This Study McLure+13 Schenker+13 Bowler+14 Bouwens+14 Bouwens+11 Tilvi+13 Castellano+10 Ouchi+09 M* = −21.03+0.37 −0.50 α = −2.03+0.21 −0.20 ϕ* = 1.57 +1.49 −0.95 x10−4 z ∼ 8 4 -17 -16 -15 -14 -13 -12 -11 -10 10-1 100 101 102 103 Number Density MUV Brighter Fainter HUDF HST FF (5x, 10x) JWST Less More Galaxy Ultra-Violet Luminosity Function at z~7 Needed to maintain reionization (e.g., Kuhlen+ 2012, Robertson+ 2013, 2015)
10. Clever idea: Look for faint galaxies at epoch of reionization Problem: Faint galaxies are hard to observe! Another clever idea: Use the stellar fossil record of nearby dwarfs galaxies to study faint galaxies at epoch of reionization or where on the high-z UVLF do LG dwarf galaxies live? Reionization and Small Scale Structure in CDM
11. Outside MW Common Distance, Foreground extinction Color ~Log Luminosity HOT COOL + Stellar Evolution Study Galaxy Evolution by Resolving Individual Stars The Stellar Fossil Record Bright Faint Young Old
12. Hotter Brighter Cooler Brighter Hotter Color-Magnitude Diagrams (CMDs) Fainter
13. Hotter Brighter Cooler Brighter Hotter Fainter CMD Fitting Ingredients Stellar evolution model IMF Stellar multiplicity age basis functions (~100) metallicity basis function (~20) distance reddening (~1-10 components) Noise model star-by-star fitting vs. binned CMD Grid Search MCMC Simulated Annealing … Computing and reporting uncertainties CMDs are Information Rich
14. Hotter Brighter Cooler Brighter Hotter CMDs are Information Rich Fainter CMD Fitting Ingredients Stellar Evolution Model IMF Stellar Multiplicity Noise model age basis functions (~100) metallicity basis function (~20) distance reddening (~1-10 components) star-by-star fitting vs. binned CMD Grid Search MCMC Simulated Annealing …
15. Fornax LG dSph Example Star Formation History Weisz+ 2014a SFH from Fossil Record ➞ M★ (z)
16. Fornax LG dSph Example Star Formation History Ancient Constant Young Weisz+ 2014a SFH from Fossil Record ➞ M★ (z)
17. Fornax LG dSph Example Star Formation History Reionization Stellar Fossil record cannot resolve sub-Gyr SF events at epoch of reionization
18. The Local Group at high z 3 Figure 1. Star formation rates calculated in bins of 200 Myr (light gray histograms) and 20 Myr (dark gray histograms) for simulated galaxies from O˜ norbe et al. (2015; left) and Fitts et al. (in preparation; center and right) up to z = 5. At the present day, each galaxy has 106 . M?(z = 0)/M . 5 ⇥ 106 and is hosted by a halo with M vir (z = 0) = 1010 M . The dotted horizontal line shows the mean SFR over the period plotted. Averaged over 200 Myr periods, the SFRs appear to be increasing to z = 7. On 20 Myr timescales, they are much burstier and fluctuate strongly. These simulated SFHs motivate the burst parametrizations we use in our modeling. ical simulations. Figure 1 shows examples of such episodic SFHs for three simulated dwarf galaxies at z > 5. Each was run using Gizmo (Hopkins 2014) with meshless finite- into a sample with redshift selection function P(z). The weights can correspond to the photometric redshift distri- bution, P(z), from an observational sample, to some modi- Use Simulations of Dwarfs as Guide for ‘Burstiness’ of SFHs at high-z SFR Lookback Time (Gyr) redshift On 200 Myr Timescales: Smoothly varying SFR, modest bin-to-bin contrast On 20 Myr Timescales: Rapidly varying SFR, high (5-20) bin-to-bin contrast Onorbe+ 2015; MBK+ 2015
19. Fluctuation amplitude & timescale matter! n the photometric redshift distribution of Finkelstein et al. and assuming that th a characteristic timescale of 20 Myr (left) or 200 Myr (right). The colors nel. In the case of 20 Myr bursts, the frequent and relatively high-amplitude n (with peaks corresponding to the burst and inter-burst periods). The 200 udes, result in a distribution that is less broad and is unimodal. This is a for 200 Myr bursts; the resulting SFH is therefore much closer to the fiducial z = 7 in each realization results in a cumulative distribution that is very Median=mode, 2 magnitude spread 4 M. Boylan-Kolchin et al. Figure 2. Probability distribution for M UV of Fornax, given the pho Fornax’s high-redshift star formation occurred in bursts with a char indicate the cumulative probability distribution in each panel. In th bursts result in a bimodal probability distribution function (with p Myr bursts, which are modeled with smaller burst amplitudes, res direct consequence of our smaller assumed burst amplitude for 200 M constant SFH. Taking the instantaneous value of M UV at z = 7 in similar to that shown here in each case. Median≠mode, 3 magnitude spread, bimodal distribution MBK et al. 2015 MUV distributions at z~7 for Fornax for select burst models 200 Myr bursts 20 Myr bursts SFH from Fossil Record ➞ M★ (z) M★ (z) + Bursts + population synthesis ➞ MUV(z) Weisz+ 2012, 2014; MBK+2015
20. MV = -4.9 MV = -16.5 dSph dIrr dTrans dE ~104M⊙ ~109M⊙ Repeat exercise to get MUV at z~7 for many LG Dwarf Galaxies Weisz+ 2014a Plus newer data Cole+ 2007, 2014 Hidalgo+ 2011 Monelli+ 2010 Brown+ 2014 …
21. The Local Group in high-z context What did the progenitors of Local Group dwarfs look like at high redshift? How will galaxies that are observable with current and future observatories evolve to the present day? MBK, Weisz, et al. 2015 Number Density MUV Brighter Fainter Less More Local Group Dwarf Galaxies at z~7 log10(MVir/M⊙ ) at z~7 MBK+ 2015
22. The Local Group in high-z context What did the progenitors of Local Group dwarfs look like at high redshift? How will galaxies that are observable with current and future observatories evolve to the present day? MBK, Weisz, et al. 2015 Number Density MUV Brighter Fainter Less More Local Group Dwarf Galaxies at z~7 log10(MVir/M⊙ ) at z~7 MBK+ 2015
23. The Local Group in high-z context What did the progenitors of Local Group dwarfs look like at high redshift? How will galaxies that are observable with current and future observatories evolve to the present day? MBK, Weisz, et al. 2015 Number Density MUV Brighter Fainter Less More Required for reionization Local Group Dwarf Galaxies at z~7 log10(MVir/M⊙ ) at z~7 MBK+ 2015
24. The Local Group in high-z context What did the progenitors of Local Group dwarfs look like at high redshift? How will galaxies that are observable with current and future observatories evolve to the present day? MBK, Weisz, et al. 2015 Number Density MUV Brighter Fainter Less More Required for reionization HST JWST Local Group Dwarf Galaxies at z~7 log10(MVir/M⊙ ) at z~7 MBK+ 2015
25. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? MVir/M⊙ at z~7 Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 MUV MBK+ 2015
26. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 Factor of 10 Mismatch MVir/M⊙ at z~7 MUV MBK+ 2015
27. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 Factor of 10 Mismatch Draco MVir/M⊙ at z~7 MUV MBK+ 2015 Fornax
28. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 Factor of 10 Mismatch Draco Some Reasons for numbers discrepancy • Satellite destruction • High-z UVLF Slope incorrect • Cosmic Variance • Completeness • Not all halos form stars • LG UV luminosities incorrect … MVir/M⊙ at z~7 MUV MBK+ 2015 Fornax
29. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 Factor of 10 Mismatch Draco Some Reasons for numbers discrepancy • Satellite destruction • High-z UVLF Slope incorrect • Cosmic Variance • Completeness • Not all halos form stars • LG UV luminosities incorrect … MVir/M⊙ at z~7 MUV MBK+ 2015 Fornax
30. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 Factor of 10 Mismatch Draco MVir/M⊙ at z~7 MUV Draco MBK+ 2015 see also O’Shea+ 2015 Broken LF slope at faint magnitudes Fornax Fornax
31. 8 M. Boylan-Kolchin et al. Figure 5. The z = 7 mass function of the main progenitors of surviving z = 0 (sub)halos – including the main progenitor of the MW itself – within 300 kpc of the Milky Way based on the ELVIS simulations (shaded region). The upper horizontal axis gives the Figure 6. Similar to Figure 5, but assumes a UV luminosity function that breaks to ↵ = 1.2 at M UV > 13 (from the fiducial value of ↵ = 2.03 for brighter galaxies). The z = 7 census of galaxies surviving to z = 0 in the Milky Way is in How many MW satellites should we see based on the high-z UVLF? Cumulative Number Number at z=0 ELVIS Sim. Garrison-Kimmel+ 2014 Factor of 10 Mismatch Draco Fornax MVir/M⊙ at z~7 MUV Draco Fornax Changes SHM relation, Faint galaxies live in more massive halos, … Broken LF slope at faint magnitudes see also O’Shea+ 2015 MBK+ 2015
32. The Local Group in high-z context What did the progenitors of Local Group dwarfs look like at high redshift? How will galaxies that are observable with current and future observatories evolve to the present day? MBK, Weisz, et al. 2015 Number Density Brighter Fainter Less More Simple LF modification for Local Group Dwarf Galaxies at z~7 log10(MVir/M⊙ ) α=-2 α=-1.2 Steep Slope: Vastly over-predict LG galaxy counts at z=0 Broken Slope: match LG counts, still get reionization MUV MBK+ 2015
33. Conclusions • There is a natural and fundamental connection between low- mass galaxies and cosmic reionization in all CDM models • Resolved stellar populations of nearby, faint galaxies may be the best pathway to study this connection • JWST unlikely to directly detect progenitors of Fornax at z~7 • Fossil Record for hundreds of low-mass galaxies within ~5 Mpc accessible with JWST • Improvements in stellar models & absolute stellar ages very important • Steep high-z UVLF slope over-predicts LG galaxy counts • Break in slope of -1.2 at MUV >-13 reconciles counts, maintains reionization • Better understanding of completeness in LG galaxy counts • Important to find more Draco to Fornax mass galaxies outside LG MBK, Weisz+ 2015 arXiv:1504.06621 Weisz+ 2014 arXiv:1409.4772 See poster by Andrew Graus
35. MW: 100% Field: ~50% M31: ~15% Fraction of dwarfs imaged below oMSTO
36. PI: E. Skillman 4 M31 satellites to oMSTO PI: N. Martin 17 M31 satellites to sub-HB/oMSTO PI: D. Weisz PegDIG & WLM to oMSTO HST Cycle 22
37. LG M81 Group Cen A Group NGC 253 Group Resolving the Local Volume
38. JWST MSTO limit LG M81 Group Cen A Group NGC 253 Group Resolving the Local Volume
39. The Local Group at high z 5 dwarfs olumn olumns , while of the ⇠ 7) (1 . 3) (1 . 5) (0 . 9) (1 . 6) (0 . 9) (1 . 4) (1 . 1) (1 . 4) (1 . 0) (1 . 6) (1 . 0) (1 . 3) (1 . 0) (1 . 4) (0 . 7) Fornax Draco