2006 December 6thMAGPOP La Palma Workshop Red Sequence formation ages Marc Balcells Collaborators GOYA Team: Carmen Eliche-Moral, David Cristbal, Lilian Domnguez, Mercedes Prieto, Marc Vallb, Carlos Lpez Tenerife Nbody Team: Carmen Eliche-Moral, Csar Gonzlez-Garca, Alfonso L. Aguerri Instituto de Astrofsica de Canarias 2006 December 6thMAGPOP La Palma Workshop Summary Major epoch of E galaxy formation: 1 < z < 2 Ancestors of L* ellipticals stopped making stars at z~1.5 (9 Gyr ago) Galaxies with centrally-peaked profiles (with bulges), 0.3 < z < 1.0: Define a Red Sequence, of Bulge Colors Galaxies without ~exponential profiles: color distribution does not show a Red Sequence Galaxies with bulges: Integrated colors define a Red Sequence as well Redder bulges live in redder galaxies, with redder disks We dont find red-old bulges surrounded by forming, blue disk Minor mergers make bulge grow from disk material 2006 December 6thMAGPOP La Palma Workshop Work in preparation for GOYA survey Major study of high-z galaxy populations Using upcoming EMIR NIR multi-object spectrograph on 10.2 m GTC UFL, UCM, Toulouse, IAC Guzmn, Gallego, Pell, Balcells 2006 December 6thMAGPOP La Palma Workshop Upcoming GTC Science funds GTC Science CONSOLIDER program Spanish ministry of Science 5 yr, 5 Meuro Postdoc opportunities to be advertised ~2007 January Covering most science large programs with GTC GOYA high-z NIR spectroscopy, EMIR OTELO narrow-band tunable filter deep survey, OSIRIS Massive stars in MW, OSIRIS, EMIR Brown dwarfs, EMIR 2006 December 6thMAGPOP La Palma Workshop GOYA Photometric Survey 0.5 square degree K=J=22 AB mag UBVRI=26 AB mag Fields: Groth GOODSN V0226 (COSMOS-10h) Other, smaller fields (excluded from spectroscopic survey?) SA68 SIRTF-FLS Coppi 2006 December 6thMAGPOP La Palma Workshop Galaxy number counts - Groth strip Blue band: power-law, up to B~25NIR band: break at K~17.5 Eliche-Moral et al (2006a) Cristbal-Hornillos et al (2003) 2006 December 6thMAGPOP La Palma Workshop Features in counts = features in LF Goal is to reproduce entire distribution of counts U,B,K 1.K counts change slope 2.U,B counts featureless power law Features in number counts = feature in LF Euclidean: 2006 December 6thMAGPOP La Palma Workshop Modeling Evolution of local LF back in time SDSS LFs, morphologically dependent Nakamura et al Ellipticals, early spirals, late spirals, Irregulars No disappearing dwarf populations Observationally-motivated model ingredients Number evolution ~(1+z) 2.0 Extinction A B =0.6 (face-on), all galaxy classes Salpeter IMF Metallicities: Solar(E,Sa-b), 0.2solar(Sd), 0.1solar(Ir) Standard star formation histories Instantaneous for ellipticals Exponentially decaying for Spirals, Irregulars Only free parameters: formation epoch for each galaxy class 2006 December 6thMAGPOP La Palma Workshop Reproduce B,K counts Simultaneously reproduce number counts in Groth, U, B, Ks Eliche-Moral et al (2006a) Wide ranges - 18 mag in B, 10 mag in Ks Late z f =1.5 for ellipticals gives knee in Ks counts Ks~17.5 Extinction prevents bump from appearing in B Number evolution gives right overall slope 2006 December 6thMAGPOP La Palma Workshop Limits on model parameters z f constrained for E. z f >2.5 does not work. For S0a-Sb, z f =1.5 to z f =4 good fit Extinction essential A B =0.2 does not work Mergers essential Otherwise, need to introduce a disappearing population Moderate variations of rate are OK IMF, metallicities: little effect Instantaneous, SSP for ellipticals necessary 2006 December 6thMAGPOP La Palma Workshop 9 Gyr broad agreement with other age determinations z=1.5: lookback-time 9 Gyr No major conflict with Population diagnostics stellar populations of cluster ellipticals: age~12 Gyr Vazdekis Field ellipticals, populations younger than 8 Gr Heavens et al 2005 Schiavon et al 2006 Distant Cluster Survey, CMD scatter: z form = Taking progenitor bias into account, ellipticals z form =2 Franx & Van Dokkum 1996 DEEP2 picture: RS starts at z=1.5 Michael Cooper, today GOODS-K20 morphology: Es disappear by z=2 Cassata et al. (2004) But is there a selection effect? M K * =-23.6 has K S =20.6 at z=2 2006 December 6thMAGPOP La Palma Workshop Duration of the elliptical formation epoch Model captures major growth phase of red sequence, 1