Simulations* in the radio waves regime for ASKAP *of galaxy formation. Claudia Lagos (ARC DECRA fellow) on behalf of ICRAR-theory group

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1 Simulations* in the radio waves regime for ASKAP *of galaxy formation Claudia Lagos (ARC DECRA fellow) on behalf of ICRAR-theory group

2 Theory/computing group at ICRAR

3 Preparing the theory for ASKAP... What's available? Properties of galaxies in the HI regime to keep in mind: We are working in two fronts: SAMs and hydrodynamical simulations. Results from new generation of multi-purpose lightcones Radio properties of galaxies currently available (HI emission, radio continuum) and in development (radio continuum, HI absorption)

4 We are exploiting two fronts of galaxy formation sims 1. Serial approaches: semi-analytic models Adrian Jenkins Why would we want to exploit both techniques, rather than focus 2. Parallel approaches: hydro-dynamical simulations on one only? Credit: Rob Crain

5 Difference between SAMs and hydro-sims In SAMs we have integrated properties: Galaxy sizes, stellar and gas masses, SFRs, metallicities, etc. Image from Lagos et al. (2013). Similar information in other models (Fu et al.; Popping et al.; Croton et al.) In hydro simulations we have the entire structure of galaxies (but volumes are much smaller). Images from Lagos et al. (2015b) and Trayford et al. (2015) (EAGLE)

6 Volumes simulated P-Millennium (produced in Durham) (800Mpc)3 resolution down to Mhalo~5x109 Msun Most amazing hydro-simulations! This means that we expect 10s of millions of gas-rich galaxies in our SAMs vs. fewx1,000 in EAGLE

7 Semi-analytic models and multi-purpose lightcones

8 Multi-purpose lightcones... SURFS suite (C. Power) VELOCIraptor (P. Elahi) GALFORM (C. Lagos) Adrian Jenkins Although lightcones can be produced for specific surveys, we are testing multipurpose lightcones (stellar mass cut only)

9 The SURFS suite of N-body simulations SURFS (Synthetic UniveRses For Surveys) Elahi et al. (in prep.) Volumes varying within ~x75,000 Resolutions varying within ~x150

10 First example of multi-purpose lightcones Lagos et al. (2012) galform model on Millennium-2 (halos resolved down to 109Msun) Advantage is that it reproduces several HI properties of galaxies (treatment of the ISM) Lagos et al. (2014a)

11 The HI of galaxies/groups in GALFORM Eckert et al. (2016; cold baryons fraction in groups) Brown et al. (2016; HI stacking of satellite galaxies) Martindale et al. (in prep.) GALFORM model

12 The SED of galaxies in GALFORM

13 Applications to HI ASKAP surveys We asked: (1) What is the HI mass distribution expected? (2) given a set of HI detections, how many GAMA (or optical/near-ir surveys) counterparts would be found? ALFALFA.40 (Papastergis+11) Duffy+12 We took galaxies with Speak>3 Unexplored territory But half of the galaxies here!! We can now ask how many counterparts in UV/optical/near-IR are expected based on these improved models/resolution! All galaxies observed

14 UV/Optical/near-IR counterparts Many r-band selected galaxies without HI detections. HDF Subaru r WAVES GAMA (2) given a set of HI detections, how many GAMA (or optical/near-ir surveys) counterparts would be found? Many HI-selected galaxies without r-band counterparts Our preliminary results call for a revision of what was done in Duffy+12, and See Elisabete's talk for thethe SAX lightcones (mainly due to improved resolution of the sims+ improved models) TAIPAN/WALLABY overlap

15 Ongoing work (to be finalised during 2016) (1) Absorption lines (using HI and velocity structure of galaxies in the model): from models+hydro-sims Prochaska & Wolfe (1997) Use the lessons from hydro-sims to estimate neutral gas in the cosmic web (Rahmati+15)

16 Ongoing work (to be finalised during 2016) (2) Radio continuum (AGN radio core is already included), but we are working now on - radio continuum from star formation - radio continuum from diffuse emission - radio continuum from AGN/outflows

17 Hydro-dynamical simulations

18 New generation of hydro-simulations Our group is extensively working with EAGLE and HORIZON-AGN Large number of sub-grid physics module: Metal-dependent cooling Reionisation Star formation Stellar recycling Stellar feedback AGN feedback (~700pc resolution, 1e6Msun, 100Mpc box size) Schaye et al.(2015); Vogelsberger (2014), Dubois et al. (2015), among others

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20 Cosmic density of gas in EAGLE Extensive work in EAGLE partitioning the gas in HII/HI/H2 Lagos et al. (2015b,2016a), Bahe et al. (2015), Crain et al. (2016), Rahmati et al. (2015,2016): - HI/H2 mass functions, gas fractions, scaling relations, relation with Mstellar and SFR at different redshfits, column density distributions (HI and high ionisation metals), etc. Atomic hydrogen-density Rahmati et al. (2015) Molecular hydrogen-density Lagos et al. (2015b)

21 The power of resolved galaxy structures In hydro simulations we have the entire structure of galaxies. Images from Lagos et al. (2016a) and Trayford et al. (2015) (EAGLE) Galaxies with the same stellar mass, SFR, HI and H2 masses but at different redshifts Sizes/angular momentum extremely sensitive to accretion flows/compactness of galaxies Lagos et al. (2016b): Using EAGLE (but similar results in Horizon-AGN)

22 The power of resolved HI maps... Bahe et al. (2015): using EAGLE Gas distribution extremely sensitive to the feedback+ism modelling in a way that we can start using that information!

23 Hydro-dynamical simulations... Our current strategy is to build-up a library of zoom-in simulations of groups and clusters (~10 to date) that can help up to: (i) Capture the variety of environmental effects on the gas (WALLABY/DINGO) (ii) Estimate the diffuse/radio continuum emission from groups/clusters (EMU) Use large cosmological boxes (EAGLE/HORIZON-AGN) to: (i) Characterise the nature of HI absorption lines (FLASH) (ii) Study AGN outflows to estimate core radio emission + lobes emission (EMU)

24 We are doing this to help maximise the science outcome of the ASKAP surveys and so we are ready to provide you with simulation data right here, right now!

25 Gas mass functions in EAGLE Crain et al. (2016) Lagos et al. (2015b) To study HI-selected galaxies in the entire range where observations exist, very high resolution is needed! (~250pc)

26 Radio diffuse emission in clusters Power et al. (in prep.): Unveiling the diffuse radio emission from shocks in groups/clusters

27 Comparison with other publicly available models

28 Environment range probed Murray, Power, Robotham (2014) 10s millions - HI gas-rich galaxies - SMGs and QSOs - ELGs LRGs somex10,000 Clusters Fewx1, Quite obvious that clustering and LSS studies require SAs - Mocks should be (and will be) generated for large LSS surveys.

29 Semi-analytic models of galaxy formation Semi-analytic models of galaxy formation Adrian Jenkins Running a suite of Nbody simulations at ICRAR Led by Chris Power Merger trees constructed using different algorithms (VELOCIraptor, SUBFIND) Led by Pascal Elahi Using GALFORM (different flavours and varying models) Led by Claudia Lagos

30 HST surveys Subaru z GAMA At the near-ir... Many (~half) z-band selected galaxies without HI detections. Many HI-selected galaxies without z-band counterparts

31 HST F225W GALEX At the near-uv... All NUV-selected galaxies (unless very faint) will have HI counterparts

32 Summary of strengths and weaknesses of each technique... Galaxy formation cares about all these scales Large Sub-grid physics Large Scale Structure ISM, star formation black hole accretion Hydro-dynamic simulations of galaxy formation Semi-analytic models of galaxy formation 1pc 100pc 100Mpc 1Gpc