Bruno Henriques Claudia Maraston & the Marie Curie Excellence Team Guinevere Kauffmann, Pierluigi Monaco Evolution of the Near-Infrared Emission from Galaxies: The End of the Challenge for Galaxy Formation Models

You cannot do galaxy formation ignoring that almost every result depends on the stellar populations assumed to obtain galaxy properties Observationally In Galaxy Formation Models Template fitting!!! – light to mass (age & metallicity) Conversions from mass to light!!! “Ignored” in models Different evolutionary population synthesis mostly agree at low z Until recently, other discrepancies with data made this effect negligible – k+evolution corrections Innsbruck6/25/ All You Need to Know

1 – Intro Galaxy Formation Models 2 – Methods From mass to light – evolutionary population synthesis 3 – Results The evolution of the near infrared emission of galaxies Innsbruck6/25/2015 4Outline

Large Sky Surveys Spatial clustering Luminosity Colour Size SFR Metal Abundance N-body + Semi-Analytics We need robust and equally precise theoretical predictions Do we understand the physical processes that produce galaxy properties obtained from large sky surveys? Innsbruck6/25/ Introduction Locally and at high z

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7 Innsbruck Dark Matter Halo Mass Hot Gas Mass 17% of baryons

Innsbruck Stars Cold Gas Hot Gas Ejected Gas Recycling Star Formation Cooling Reheating Ejection Reincorporation Stars 6/25/2015 8

9 Innsbruck6/25/2015 From Mass to Light Stellar Population Synthesis Dust Model ISM + Molecular Clouds Conversion to Observables Stellar, cold and hot gas masses and metallicities Ages and star formation rates Luminosities and Colours

Stars Ejected Gas Cold Gas Hot Gas For every fraction of cold gas mass turned into stars Knowing the metallicity and age of the material and assuming an IMF EPS assign a given spectrum Stars Innsbruck6/25/ Evolutionary Population Synthesis

K-band The inclusion of the TP-AGB phase means that intermediate-age populations will contribute significantly to the near infra-red emission from galaxies In previous evolutionary population synthesis codes, the K-band was mostly determined by old populations (e.g. Bruzual & Charlot 2003, PEGASE, Starburst99) i-bandz-band Innsbruck6/25/ The TP-AGB Phase – Maraston 2005

Innsbruck6/25/ Van der Wel, Franx, Wuyts, et al Chandra Deep Field - South ACS+IRAC+J&H filters

Older then the Universe! Undetected in MIPS! Innsbruck6/25/ Maraston, Daddi, Renzini, et al What are the implications for galaxy formation models?

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Innsbruck6/25/ B-V vs V-K Rest-Frame Colours Daddi, Dickinson, Morrison, et al GOODS – ugriz+JHK+IRAC filters B-V (rest-frame) V-K (rest-frame) Tonini, Maraston, Thomas et al. 2009

Conclusions If you work on galaxy formation do mind stellar populations! The TP-AGB phase is essential for the models to reproduce the observed evolution of the near-infrared emission from galaxies over the history of the Universe. K-band evolution is no longer a problem!

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Stars Ejected Gas Cold Gas Hot Gas Semi-Analytic models of galaxy formation predict intrinsic properties: Stellar, cold and hot gas masses and metallicities Ages and star formation rates Observations give: Luminosities and Colours Stars Innsbruck6/25/ – Evolutionary Population Synthesis

Musyc – Gawiser et al Goods – Giavalisco et al Optical to mid-infrared data The Stellar Mass Function – Marchesini et al Innsbruck6/25/

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Uncertainties on K-corrections Difference on the k-correction derived using BC03 or Maraston05 Innsbruck6/25/

Innsbruck6/25/ GYr

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