IAU Commission 28 - Galaxies Highlights Conferences New OC 2 1- Star formation with Spitzer and Galex Star formation increases with z: Noeske et al galaxies AEGIS Groth Strip Blue: 24 + Emission lines Green: no 24 SF from EM, red Gradual process of SF decline with time: gas exhaustion? 24 and H tracers of SFR Messier 51 Kennicutt et al 2007 Depends on the pixel average, Best on 520pc M51 3 2- Extended UV (XUV) disks Gil de Paz et al 2007 Abundances in the outer parts are not pristine material, but like 1Gyr old disks Type 1 UV NIR-opt UV NIR-opt Type 2 Thilker et al 2007 Frequent extended UV Might be episodic gas accretion 4 3- Colour Bimodality and downsizing 30% of z~2 galaxies detected in 24 show excess of mid-IR % star formation. Stacked X-ray reveal Compton-thick AGN Fraction increases with mass, and with z 60% M> Mo Daddi et al 2007 Origin of bimodality? Cold gas accretion at low M Quenching of star formation M>Mo Dekel & Birnboim 2006 5 4- Evolution and High-z galaxies Kristen et al 08, Genzel et al 08 Distinguishing between mergers and normal galaxies? Tacconi et al 2006 6 5- Scaling laws and time evolution Sheth et al 2008 Trachternach et al 2009 Baryonic Tully-Fisher Constraint on triaxiality 7 6- Numerical simulations Via Lactea Diemand et al 2007 Di Matteo et al 2007, 08 Retrograde mergers produce more starbursts Globally, only a few % of starburst due to mergers Satellite problem more accute 8 Conferences IAU S230: Populations of High Energy Sources in Galaxies, Aug 2005, Dublin, Ir 11th Latin-American Regional IAU Meeting (LARIM-2005), Dec05, Pucon, Chile IAU S235 : Galaxy Evolution across the Hubble Time, Aug 2006, Prague, Cz JD07: The Universe at z>6, Aug 2006, Prague, Cz IAU S238: Black Holes -- from Stars to Galaxies, Aug 2006, Prague, Cz IAU S241: Stellar Populations as Building Blocks of Galaxies, Dec 2006, Canaries, Sp IAU S244: Dark Galaxies and Lost Baryons, June 2007, Cardiff, UK IAU S245: Formation and Evolution of Galaxy Bulges, July 2007, Oxford, UK IAU S254: The Galaxy Disk in Cosmological Context, June 2008 Copenhagen, Dk IAU S255 : Low-Metallicity Star Formation, June 2008, Rapallo, Liguria, It IAU S256 The Magellanic System: Stars, Gas, and Galaxies, July 2008, Keele, UK other meetings relevant to Galaxies (cited in the report, ) 10 times more than IAU! 9 Commission actions New Organising Committee for President Roger Davies (UK) Vice President Jay Gallagher (USA) New OC members Stephane Courteau (Canada) Chanda Jog (India) Sharda Jogee (USA) Linda Tacconi (Germany) Elena Terlevich (Mex) Continuing OC members Francoise Combes (F, past-president) Avishai Dekel (Israel) Marijn Franx (NL) Naomasa Nakai (Japan) Monica Rubio (Chile) Main actions: Review meeting proposals Proposition of Working Groups Large surveys? IAU GA 2012