ALMA Observations of Gas-rich Galaxies in z~1.6 Galaxy Clusters: - PowerPoint PPT Presentation

ALMA Observations of Gas-rich Galaxies in z~1.6 Galaxy Clusters: Evidence for Higher Gas Fractions in High-Density Environments Noble et al. 2017, ApJL, 842, 21 arXiv:1705.03062 HST 105 140 160 J0224 − 396 ALMA CO (2 − 1) HST 160 J0225 − 541 ALMA CO (2 − 1) 0.60 0.60 J0224 − 424 0.40 0.40 Jy beam − 1 km s − 1 Allison G. Noble − 0.20 0.20 − 0.00 0.00 − 0.20 − 0.20 1 ′′ 5 ′′ 1 ′′ 5 ′′ Mike McDonald, Adam Muzzin, Julie Nantais, Greg Rudnick, Eelco van Kampen, Tracy Webb, Gillian Wilson, Howard Yee, and the SpARCS Collaboration

Breakthroughs in Galaxy Evolution Decline in cosmic star Existence of star-forming formation rate density main sequence Lookback time (Gyr) 2 4 6 8 10 12 0 –0.4 c log ψ (M year –1 Mpc –3 ) –0.8 –1.2 –1.6 –2 –2.40 8 1 2 3 4 5 6 7 Redshift Madau & Dickinson 2014 Whitaker et al. 2014 What drives these trends?

Breakthroughs in Galaxy Evolution Decline in cosmic molecular Dependence on star-forming gas mass density main sequence credit: A. Saintonge Decarli et al. 2017 Gas Regulation

Evolution of Molecular Gas in the Field 3 redshift 0 1 2 COLD GASS PHIBSS 1/2 Lensed Galaxies (e.g. Saintonge+2011, (e.g. Tacconi+2010, 2013, (e.g. Baker+2004; Coppin 2012; Kauffmann+ 2017) +2007; Saintonge+2013) 2012) PEP FCRAO SMGs Extragalactic CO (e.g. Magnelli+2012) (e.g. Reichers+2011; Hodge+2012) (e.g. Young+1995) IRAM FCRAO VLA

Evolution of Molecular Gas in Clusters z < 0.5 1 < z < 1.5 Protoclusters 3 redshift 0 1 2 Ivison+2012 Emonts+2013 Stark+1986 Wagg+2012 Riechers+2010 Dannerbauer+2017 Kenney&Young 1989 Casasola+2013 Walter+2012 Chapman+2015 Casoli+1991 Aravena+2012 Hodge+2013 Boselli+1997 Tadaki+2014 N = 4 Tan+2014 Fumagalli+2009 Ivison+2013 Scott+2013 N ~15 N~100 Boselli+2014 missing CO in …until this year Mok+2016 massive clusters (e.g. Noble+2017; Cybulski+2016 at z>1.5 Rudnick+2017; Geach+2011 Hayashi+2017; Stach+2017) Jablonka+2013

Why z >1.5 clusters? 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 z ∼ 0 z ∼ 0 z ∼ 0 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 z ∼ 1 z ∼ 1 Passive Fraction Passive Fraction Passive Fraction Passive Fraction z ∼ 1.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.5 10.5 10.5 10.5 10.5 10.5 10.5 10.5 11.0 11.0 11.0 11.0 11.0 11.0 11.0 11.0 11.5 11.5 11.5 11.5 11.5 11.5 11.5 11.5 Log M stellar (M O Log M stellar (M O Log M stellar (M O Log M stellar (M O • ) • ) • ) • ) Balogh et al. 2016 van der Burg et al. 2014 Nantais et al. 2016

3 SpARCS Clusters at z~1.6 • ~115 spectroscopically confirmed cluster members • richness-based masses >10 14 M ⊙ • 11-band photometry for stellar masses ( ugrizYK [3.6][4.5][5.0][8.0]) • MIPS and Herschel -imaging (24/250/350/500 um) for infrared-SFRs gz[3.6] 4’ Nantais et al. 2016

ALMA CO (2-1) Observations CO (2-1) detection in z~1.6 cluster galaxy! 13 hours of ALMA time (PI Noble) for 3 z~1.6 SpARCS clusters to detect CO 2-1 2 pointings (FOV~110”) per cluster, encompassing 49 known spectroscopically-confirmed cluster members 110” 11 CO (2-1) detections 88.23 GHz, 100 km/s channel with S/N > 5 in z~1.6 rms ~ 0.17 mJy/beam in 100 km/s cluster galaxies beam ~ 4.4” x 2.2” Noble et al 2017

ALMA CO (2-1) Observations 6” x 6” HST 30” x 30” CO Moment 0 Close pairs Noble et al. 2017

SFR - M Plane z ∼ 1.6 cluster z ∼ 1.6 cluster 0.8 CO detections CO detections Star Formation Rate pair galaxies pair galaxies Main Sequence 0.7 at fixed z MS at z=1.6 higher SFE 100 100 100 100 • yr -1 ) • yr -1 ) Gas Fraction higher gas fraction 0.6 SFR (M O SFR (M O 0.5 lower SFE 0.4 lower gas fraction 0.3 10 10 10 10 10 10 10 10 10 10 10 10 10 11 10 11 10 11 10 11 M stellar M stellar (M O M stellar (M O • ) • ) Noble et al. 2017 f gas = M gas / (M gas + M stellar ) see Saintonge et al. 2011, 2016; Genzel et al. 2015

Gas Fractions in z~1.6 Cluster Galaxies 11.2 log M stellar = 10.0 log M stellar = 10.0 2 2 scaling relation, scaling relation, scaling relation, scaling relation, z~1.6 cluster . . 3 3 3 3 3 3 3 3 3 3 1 1 log M stellar = 10.9 log M stellar = 10.9 log M stellar = 10.9 log M stellar = 10.9 1 1 = = galaxies are at cluster detections M stellar M stellar systematically 11.0 g g higher gas fractions o o (SFR − SFR MS ) / SFR MS (SFR − SFR MS ) / SFR MS (SFR − SFR MS ) / SFR MS (SFR − SFR MS ) / SFR MS (SFR − SFR MS ) / SFR MS l l 2 2 2 2 2 2 2 2 2 2 (4 σ ) than the field 10.8 log (M stellar ) field at z=1.6 (Genzel+2015) M mol = α CO x L CO 10.6 1 1 1 1 1 1 1 1 1 1 10.4 clusters require 0 0 0 0 0 0 0 0 0 0 different conversion 10.2 between CO and H 2 from field? − 1 − 1 − 1 − 1 − 1 − 1 − 1 − 1 − 1 − 1 10.0 see e.g., Bolatto et al. 2013; Narayanan et al. 2012 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 f gas = M gas / (M gas +M stellar ) f gas = M gas / (M gas +M stellar ) f gas = M gas / (M gas +M stellar ) f gas = M gas / (M gas +M stellar ) f gas = M gas / (M gas +M stellar ) Noble et al. 2017

Conclusions • 11 CO (2-1) detections in z~1.6 SpARCS clusters • evidence for systematically higher gas fractions in SpARCS clusters compared to the field scaling relations at z~1.6 - clusters require different conversion between CO and H 2 from field? - high cluster-to-cluster variation • high-z clusters look to be exciting prospects for detecting gas- rich galaxies - need more CO observations! Thank You!