Christian Maier, ETH Zurich

1. Star-forming zCOSMOS-Deep galaxies at 2<z<2.5: SFRs, morphologies, sizes, Ly-α emission/absorption, UV absorption features (from Platefit, Fabrice talk) Christian Maier, ETH Zurich

2. zCOSMOS-Deep galaxies at 2<z<2.5 from the 3k sample • Figure: distribution of zCOSMOS-Deep galaxies from the 4.5k-sample with flags 3+4 (left), and flags 3+4+2.5 (right); color-coded: Ly-αemission/absorption in the spectra of 3k-zC-Deep catalog galaxies

3. zCOSMOS-Deep galaxies at 2<z<2.5: morphologies, SFRs • Figure: the highest SFR galaxies (in increasing order of SFR) with Ly-α in emission: candidates for MOIRCS • Id, SED SFR (ZEBRA), rpet50 (ZEST+), rpet90/rpet50=concentration (ZEST+) • Rpet50, rpet90 also available for SDSS for comparison (see e.g. Maier et al. 2009, SFR – ΣM paper)

4. zCOSMOS-Deep galaxies at 2.1<z<2.5:morphologies vs. Ly-α emission/absorption for the 3k • I used 138 galaxies with flag 3+4 at 2.1<z<2.5 selected from the 3k-catalog and looked at the ACS images and individual zCOSMOS spectra • Morphologies classified using scheme of Law et al. (2007) • There are more galaxies with Ly-α absorption in galaxies with nebulous morphologies (which are possibly also dustier)

5. zCOSMOS-Deep 3k galaxies at 2.1<z<2.5: SFRs, masses, and sizes vs. Ly-α emission/absorption • For the 138 zCOSMOS-Deep 3k galaxies with flag 3+4 at 2.1<z<2.5, SFR are computed from the SEDs, and sizes are the radii rpet50 containing 50% of the Petrosian flux • the rpet50 for SDSS galaxies is larger for SDSS objects of similar mass compared to zCosmos  smaller sizes at z~2.3 • The average size of Ly-α emitting galaxies at z~2.3 is smaller than for the galaxies with Ly-α absorption  consistent with more galaxies with Ly-α absorption being observed in galaxies with nebulous morphologies (previous diagram)

7. Star-forming zCOSMOS-Deep galaxies at 2<z<2.5: SFRs, morphologies, sizes, Ly-α emission/absorption, UV absorption features (from Platefit TBD)and link with [O/H] metallicities from Subaru (VLT) near IR spectroscopy Christian Maier, ETH Zurich PI of accepted Subaru/MOIRCS observing program: 2.5 nights for JHK near IR spectroscopy of 2<z<2.5 zCOSMOS-Deep galaxies

8. zCOSMOS-Deep galaxies at 2<z<2.5: candidates for MOIRCS near-infrared spectroscopy • MOIRCS (multi-object infrared camera and spectrograph) at the Subaru telescope has a field of view of 4x7 square arcminutes, resolution of R=1500 in K (Hα and [NII] at z~2.3), and R~3000 in J ([OII] at z~2.3) and H (Hβ and [OIII] at z~2.3)  goal is to measure reliable [O/H] abundances for the first time at z>2 using all 5 main optical emission lines • VLT/SINFONI proposal with similar science aim  TAC result expected in July

9. zCOSMOS-Deep galaxies at 2<z<2.5: anomalous line-ratios • Erb et al. , 4 galaxies with 4 emission lines measured at z>2 to be used in BPT diagram • Goal of MOIRCS observations: distinguish likely causes for anomalous emission-line ratios: the AGN contribution or the difference in the physical conditions (ionization parameter, SFR surface densities etc.) Window to observe all 5 emission lines is narrow

11. The metallicity-environment relation of star-forming (with emission lines) zCOSMOS-Bright galaxies at 0.5<z<1 and the role of metal poor galaxies (work in progress with 10k: better suited for 20k?) Christian Maier, ETH Zurich

12. 10k zCOSMOS 0.5<z<1 star-forming (with Em. lines) galaxies • Only 620 galaxies at 0.5<z<1 in the 10k sample have a S/N>3 in [OII], Hβ, and [OIII] • Overdensities from Kovac et al. 2009 (using the 5th nearest neighbor) are shown for D1 in blue, and the highest overdensity bin D3 in red logMass • At higher masses logM>10.2 and z>0.7 statistics become quite poor  20k will be better suitable for this study (see also next slides)

13. [O/H]-environment relation for 0.5<z<0.75: logO32 vs. logR23 • 9.6<logM<10.2: In D1 (right panels) there are several galaxies with high logO32 (metal poor galaxies), while they are almost completely absent in D3 (left panels) • 10.2<logM<10.8: statistics are very poor

14. [O/H]-environment relation for 0.5<z<0.9: logO32 vs. logR23 • 9.6<logM<9.9: In D1 there are several galaxies with high logO32 at 0.5<z<0.7, while they are almost completely absent in D1 at 0.7<z<0.9 • 9.9<logM<10.2: statistics are very poor  20 k will be better suited for this analysis

15. Breaking the R23 degeneracy using SDSS galaxies • Almost all SDSS galaxies at 0.1<z<0.385 with [NII]/Hα<0.1 (low [O/H] branch) lie in the region with [OIII]/ Hβ>1.8 and [OIII]/[OII]>0.5 • Next diagrams: assume that zCOSMOS galaxies in this region also have [O/H] on low R23 (metallicity) branch • Near-infrared spectroscopy is needed to break R23 degeneracy and determine reliable [O/H] abundances • Proposed VLT/ISAAC observing program to observe 25 zCOSMOS-Bright galaxies at 0.5<z<1 in J-band to measure their Hα and [NII] lines  TAC result in July

16. MB-[O/H] and Mass-[O/H] relations as f(Env) for 0.5<z<1 D1 • CFRS galaxies with 5 emission line measured using ISAAC near infrared spectroscopy (Maier et al. 2005) • Are there massive young galaxies in low density environment (D1) which form later and therefore have low [O/H] at z~0.7? • Maier et al. 2005: Pegase models with SFR~exp(-t/t1)/t1, assuming the galaxy is built up by continuous infall of primordial gas with an infall rate ~exp(-t/tinf)/tinf • Models with tinf<<t1: closed-box like

17. MB-[O/H] and Mass-[O/H] relations as f(Env) for 0.5<z<1 D3 • There are more low [O/H] objects in D1 compared to D3 • Are there strong starbursts in dwarf galaxies (driven by close companion e.g.)? • Close-box like models for some galaxies? • Accretion of large amount of pristine gas? Models with tinf<t1: galaxy reaches a high metallicity at early times Models with t=tinf: model galaxy reaches end metallicity after ~1Gyr, then [O/H] almost constant while luminosity decreases