Nature vs. Nurture – Is There a Mass-­‐Metallicity Dependence on Environment for z>1.5? Glenn Kacprzak
Future Fellow – Swinburne University
Rebecca Allen
Michael Cowley
Chiaki Kobayshi
Themiya Nanyakkara
Lee Spitler
Kim-Vy Tran
Tiantian Yuan
Karl Glazebrooke
Lisa Kewley
Ivo Labbe
Caroline Straatman
Philip Taylor
Adam Tomczak
Nature vs. Nurture Field Galaxies:
Halo mass
Gas Inflow/outflow
galaxy-galaxy interactions
Cluster Galaxies:
Truncation of inflows
more interactions
ICM processes
Previous Results at z=2 field cluster Shimakawa et al. 2014 Also see Valen9no et al. 2014 Kulas et al. 2013 Spectroscopically Confirmed Cluster at z=2.095 57 Confirmed members
σ=552±52 km/s
Yuan et al. 2014, Spitler et al. 2012 Mass-­‐Metallicity Cluster and Field Sample 43 cluster galaxies - Hα > 3σ
<z>= 2.095±0.004
74 field galaxies - Hα > 3σ
<z>= 2.195±0.083
Kacprzak et al. 2015 – to submit this week. Mass-­‐Metallicity of the Cluster and Field at z=2 Kacprzak et al. 2015 Fit: 12+log(O/H)= yi +mi(M-­‐10) Offset between field and cluster = 0.014±0.035dex Are all clusters the same? Mass-­‐Metallicity Rela\on at z=1.62 IRC 0218 z=1.62 Papovich et al. 2010 Tran et al. 2010 Cluster galaxies have a similar MMR as field galaxies at z=1.6 Tran et al. 2015, in prep. Simulated Mass-­‐Metallicity Rela\on at z=2 Gadget-­‐3 based hydro-­‐code Includes: relevant baryon physics, such as star forma9on, feedback from SN & AGN, & chemical enrichment from SNII & Ia & asympto9c giant branch stars Taylor & Kobayashi 2014 Taylor & Kobayashi 2015, in prep Max offset of 0.1dex Kacprzak et al. 2015 Conclusions I. -­‐  Contrary to previous results, we find no difference between the MMR for field & cluster galaxies in two clusters at z=2 and z=1.6. (offsets <0.02dex) -­‐  Consistent with current simula9ons. -­‐  Consistent with small (<0.05dex) offsets found at z=0. -­‐  Nature wins! Halo mass and internal processes play a major role in the chemical evolu9on of galaxies, while environment does not. Proper\es of field and cluster galaxies at z=2 UVJ and photo-­‐z selected field and cluster galaxies between 2.0 <z < 2.2 Rebecca Allen et al. 2015, submi`ed Sizes of field and cluster galaxies at z=2 GALFIT sizes from HST/WFC3 F160W (van der Wel et al. 2014). Field r1/2= 1.81±0.29 kpc Cluster r1/2= 2.17±0.63 kpc Allen et al. 2015, submi`ed Field r1/2= 3.57±0.10 kpc Cluster r1/2= 4.00±0.26 kpc Differ by 1.5σ Colors of field & cluster galaxies at z=2 Differ by 2.0σ Color gradients of field & cluster galaxies at z=2 Allen et al. 2015, submi`ed Color gradients seen for massive galaxies – sugges\ve of growth via minor mergers Conclusions II. Cluster Field SF field galaxies: Smaller 1.5sigma Bluer 2.0 sigma Likely grow by minor mergers SF clusters galaxies: Larger 1.5sigma Redder 2.0 sigma Missing sensi9vity to Determine of Quiescent Galaxies differ