How common are DSFGs in galaxy cluster progenitors?

How common are DSFGs in galaxy cluster progenitors? z~6 z~3 z~1 z~0 IGM, ICM, GALAXIES Casey et al. 2015a, Hung et al. 2016, Casey 2016, Champagne et al., in prep. Caitlin M. Casey Assistant Professor University of Texas at Austin

Jaclyn Champagne Molecular gas content of galaxies in overdense environments Patrick Drew Kinematics & Optical/NIR spectroscopy of DSFGs Sinclaire Manning e-merlin radio morphology of galaxies in SuperCLASS Chao-Ling Hung Jorge Zavala Justin Spilker

z~6 z~3 z~1 z~0 IGM, ICM, GALAXIES protocluster stage virialized cluster stage 1. Can DSFGs be useful tools in studying the assembly history of protoclusters (galaxy cluster progenitors)? 2. Do DSFGs (at z>2) preferentially live in overdensities?

1. Review / known DSFG-rich overdensities at z>2: convince you that they are real. (Omitting discussion of overdensities that are not spectroscopicallyconfirmed, Planck candidates, flux excesses, etc.) 2. In Context / Expectation from simulations and physical implications. (Simultaneous triggering of DSFGs vs. random triggering?) 3. Outlook / What should we aim to measure from future large submm+oir datasets?

SSA22 at z=3.09 * 4 Lyman- blobs with submm emission (Geach et al. 2005, Chapman et al. 2005) * 283 LAE Candidates spanning ~1/2 degree (Hayashino et al. 2004, Matsuda et al. 2005) SSA22 Protocluster at z=3.09, 5-8 DSFGs associated with LABs Steidel et al. (1998), Hayashino et al. (2004), Matsuda et al. (2005), Yamada et al. (2012) * ALMA follow-up reveal 9 DSFGs in core (Umehata et al. 2015)

SSA22 at z=3.09 30 x 40 x 40 Mpc comoving Matsuda et al. (2005)

HDF z=1.99 Structure * Marginal significance (~2.5) in HDF spectroscopic samples of LBGs, much higher significance in DSFGs Blain et al. (2004), Chapman et al. (2009) * Contains some well-studied systems: HDF254/255 DSFG pair (mergers) HDF147 (massive radio galaxy) HDF130 (relic FRII galaxy) Casey et al. (2009a,b), Fabian et al. (2009), Bothwell et al. (2010) Chapman et al. (2009)

HDF z=1.99 Structure HDF147 HDF254 HDF255 HDF Overdensity at z=1.99, 6-9 DSFGs HDF130 Chapman Blain et al. et (2004), al. (2009) Chapman et al. (2009)

HDF z=1.99 Structure HDF147 HDF254 Inverse compton ghost of radio galaxy (~FRII luminosity); Fabian et al. (2009) HDF255 HDF Overdensity at z=1.99, 6-9 DSFGs HDF130 Chapman Blain et al. et (2004), al. (2009) Chapman et al. (2009)

HDF z=1.99 Structure Radio galaxies in/ around protoclusters? Cosmic Downsizing: Most rare, evolved galaxies should live in most massive overdensities at early times We estimate that roughly 75% of powerful (L 2.7GHz > 1033 erg s 1 Hz 1 sr 1) high redshift radio galaxies reside in a protocluster. Carilli et al. (2001), Stevens et al. (2003), Miley et al. (2004), Venemans et al. (2004, 2007), Tamura et al. (2009), Mostardi et al. (2013), Lee et al. (2014) Venemans et al. 2007 Inverse compton ghost of radio galaxy (~FRII luminosity); Fabian et al. (2009)

Spiderweb z=2.16 Structure * strong excess of Ly emitters around radio galaxy Kurk et al. (2000, 2004a,b), Pentericci et al. (2000), Hatch et al. (2011b) * statistical excess of submm emission around Spiderweb galaxy (the cd progenitor) CO(1-0) extending 150kpc in Spiderweb s (Emonts et al. 2016) and around HAE229 (Dannerbauer et al. 2017) Stevens et al. (2003), Miley et al. (2006), Rigby et al. (2014), Valtchanov et al. (2013) * 16 LABOCA sources detected in Dannerbauer et al. (2014), five DSFGs spectroscopicallyconfirmed at z=2.16

COSMOS z=2.47 Structure * Found via statistical overdensity of DSFGs: 9 DSFGs spectroscopically-confirmed with MOSFIRE (H ) and CO Casey et al. (2015a) * Confirmed through zcosmos N(z) distribution with ~3.5 significance * As large as SSA22 structure, less complete (similar to HDF structure) Casey et al. (2015a) * Related structures also reported: Chiang et al. (2015) at z=2.44, Diener et al. (2015) at z=2.45, T. Wang et al. (2016) at z=2.50

COSMOS z=2.47 Structure Casey et al. (2015a) * Related structures also reported: Chiang et al. (2015) at z=2.44, Diener et al. (2015) at z=2.45, T. Wang et al. (2016) at z=2.50

COSMOS z=2.47 Structure 20 *peculiar velocities (infall) would only mean the structure is more elongated* VLA CO(1-0) map, 16 detections: Champagne et al. in prep T. Wang et al. (2016) structure appears to be a line-of-sight filament within the larger structure, not virialized cluster core.

COSMOS z=2.47 Structure K.-G. Lee et al. 2015, 2016

COSMOS z=2.10 Structure T. Yuan et al. (2014) * Found in zfourge team intermediate-band imaging, MOSFIRE follow up via Swinburne, 100 sources in H Spitler et al. (2012), Yuan et al. (2014) * Also present in zcosmos catalog, and on larger scales, contains: - 9 DSFGs - 5 X-ray AGN Casey et al. (2012c), Hung et al. (2016) Hung, Casey et al. 2016

Higher-redshift Overdensities with DSFGs less spectroscopically robust (50-100s of members vs. ~10) SPT2349 at z=4.3 + others? AzTEC3 z=5.3 Capak et al. (2011) N(gals) = 11 N(rare) = 2 HDF850.1 Walter et al. (2012) N(gals) = 13 N(rare) = 2 GN20 z=4.06 Hodge et al. (2013) N(gals) = 8 N(rare) = 3

SSA22 z=3.09, HDF z=1.99, Spiderweb z=2.16, COSMOS z=2.47 and z=2.10. 40 x 40 x 40 Mpc comoving Are there more? Selection is messy and heterogeneous.

SSA22 z=3.09, HDF z=1.99, Spiderweb z=2.16, COSMOS z=2.47 and z=2.10. 40 x 40 x 40 Mpc comoving Are there more? Selection is messy and heterogeneous. What should we expect?

Expectation from Simulations: Protocluster Size D[h 1 cmpc] Protoclusters are physically HUGE, and the most massive progenitors are the largest. Muldrew et al. (2015) Volume collapses by a factor of ~100 between z=3 and z=0.5. (Quantities measured related to protoclusters should consider this volume transformation) STOP LOOKING ON ~ARCMIN SCALES. Chiang et al. (2013); see also Oñorbe et al. (2014)

Expectation from Simulations: Will it collapse? Mo & White 1996: Press-Schechter spherical collapse: probability of collapse needs to exceed critical value Non-virialized structures are in nonlinear regime, direct SAM output needed to predict collapse (Chiang et al. 2013, Granato et al. 2015, Lacey et al. 2015) Chiang et al. (2013)

Expectation from Simulations: Will it collapse? Mo & White 1996: Press-Schechter spherical collapse: probability of collapse needs to exceed critical value HDF z=1.99 COS z=2.47 COS z=2.10 SSA22 SW z=2.16 Non-virialized structures are in nonlinear regime, direct SAM output needed to predict collapse (Chiang et al. 2013, Granato et al. 2015, Lacey et al. 2015) Chiang et al. (2013)

Expectation from Simulations: Protocluster SFRD epoch of interest Chiang et al. (2017)

Galaxy overdensities trace the underlying dark matter overdensity. How well they trace it is bias. gal = (N obs N exp ) N exp 1+b mass = C(1 + gal ) b gal / mass How does the bias in SMGs compare to the bias in normal galaxies (LBGs)?

How does the bias in SMGs compare to the bias in normal galaxies (LBGs)?

Expectation from Simulations: SMG bias i.e. where are the SMGs? Miller et al. (2015) : Bolshoi simulation (SAM/ large volume), eight 2deg 2 light cones, SFR-halo mass relation to scale to S 850. (Klypin, Trujillo-Gomez & Primack 2011; Behroozi et al. 2013; Hayward et al. 2013) SMGs appear to have high bias, but poisson noise means they don t usually trace overdensities, with a few exceptions.

Expectation from Simulations: SMG bias i.e. where are the SMGs? only ~10% of all 10 15 Msun massive protoclusters should have A LOT of SMGs Blain et al. (2004) Casey 2016

DSFG-rich (N>5) protoclusters should not exist. (at least in our small/incomplete surveys). What does their existence teach us?

Importance of Timescales. z=1 (or z=0) cluster with ~50 ellipticals over >10 11 Msun cosmic time How likely is it to see N DSFGs (simultaneously) in a given protocluster? Casey 2016

Importance of Timescales. z=1 (or z=0) cluster with ~50 ellipticals over >10 11 Msun 1<z<7: When were they DSFGs? How likely is it to see N DSFGs (simultaneously) in a given protocluster? cosmic time Casey 2016

Importance of Timescales. z~7 z~1 z=1 (or z=0) cluster with ~50 ellipticals over >10 11 Msun 1<z<7: When were they DSFGs? How likely is it to see N DSFGs (simultaneously) in a given protocluster? cosmic time Casey 2016

Importance of Timescales. p(5 100 ) = 4% Casey (2016)

Importance of Timescales. DSFGs: short-lived, ~100Myr. Derived directly from gas depletion times; Greve et al. 2005, Bothwell et al. 2010, Swinbank et al. 2014 SFR time luminous AGN, QSO lifetimes? <100Myr. DSFGs: long-lived, ~1Gyr. Daddi et al. 2009, Carilli et al. 2009, Hodge et al. 2012, Narayanan et al. 2015 high SFR sustainable for up to 1Gyr? building galaxies 10 12 M Correlated Triggering: protoclusters light up with DSFGs/QSOs DSFGs should be ubiquitous in protoclusters

Gas Depletion timescale gives a useful constraint on starburst lifetime. Average depletion time/lifetime for DSFGs is ~100Myr (Bothwell et al. 2013, Swinbank et al. 2014) cumulative distribution of depletion time for 7 DSFGs in protoclusters Casey 2016

Gas Depletion timescale gives a useful constraint on starburst lifetime. Average depletion time/lifetime for DSFGs is ~100Myr (Bothwell et al. 2013, Swinbank et al. 2014) 100 s of Msun/yr in accretion (in field)! cumulative distribution of depletion time for 7 DSFGs in protoclusters Casey 2016 Scoville et al. (2017) Depletion timescale means nothing if there s ongoing gas accretion. - Scoville / Hayward

They shouldn t exist (unless simulations are having trouble reproducing SMGs ) Even if depletion times aren t valid starburst lifetimes the stellar mass function can be used as an upper limit to DSFG growth. Predicted forward growth of COSMOS z=2.47 structure to z=1.8 12.0 12.5

They shouldn t exist (unless simulations are having trouble reproducing SMGs ) Even if depletion times aren t valid starburst lifetimes the stellar mass function can be used as an upper limit to DSFG growth. QSO lifetimes must be short! Predicted forward growth of COSMOS z=2.47 structure to z=1.8 12.0 12.5 Martini (2004), Merloni et al. (2004)

What can we hope to constrain? * Protoclusters are rare but the Universe is big * To learn about their growth and impact on galaxies you need statistics: what fraction of protoclusters are DSFG-rich? * wide-field surveys: mm matched with spec-z campaigns like HETDEX

Summary DSFG-rich protoclusters EXIST and are HUGE. We can start to use them to learn about physics of cluster assembly (Casey 2016). **though not every protocluster will be DSFG-rich** Wilkinson et al. (2017) Provocative question: is some large fraction of z>4 star-formation obscured and living in DSFGs in overdensities?

Miller et al. (2015)

Casey 2016