Yingjie Peng

I am working with Prof. Simon Lilly on galaxy formation and evolution in SDSS and zCOSMOS.

The zCOSMOS programme on the VLT is securing spectroscopic redshifts for a very large number of galaxies and quasars over the whole redshift range 0 < z < 3.5, using the VIMOS spectrograph. This allows the environment of galaxies to be characterised on all scales from that of the immediate group environment, 100 kpc, up to the 100 Mpc scales of the cosmic web. The zCOSMOS-bright part of the survey will ultimately obtain over 20,000 spectra selected to have I(AB) < 22.5. With this flux limit, the redshift range of the majority of the observed galaxies will be 0< z< 1.4. The z zCOSMOS-deep programme aims for higher redshift range, 1.4< z< 3 using various colour-selection criteria.

The SDSS Data Release 7 (DR7): The DR7 imaging data cover about 8423 square degrees of "legacy" sky, with information on roughly 230 million distinct photometric objects, and about 3240 square degrees of SEGUE sky, with about 127 million distinct objects (including many stars at low latitude). The DR7 spectroscopic data include data from 1802 main survey plates of 640 spectra each, and cover 8200 square degrees.

The zCOSMOS-bright 10k-sample VS. SDSS dr7

I am also a core member of the SINFONI team working on High-resolution SINFONI+AO tomography of z~2 star-forming galaxies: witnessing the growth of disks and bulges (PI: Alvio Renzini)

Motivated by both observational and theoretical developments, a paradigm shift is under way in galaxy formation and evolution, in which smooth accretion of cold gas plays a major, and possibly dominant, role compared to dark matter merging events. Our program will test this paradigm. The specific strategy is to draw from the large zCOSMOS survey and the previous MPE-led SINS survey a suitable set of ~20 "benchmark" galaxies at 1.5 < z < 2.5 with proper sampling of the stellar mass versus star formation rate relation for star-forming galaxies, all observed with AO+SINFONI. For a subset of those, the aim is then to push ultra-deep to allow detailed studies of the dynamical/morphological substructure on ~ 1 kpc scales (individual clumps, nuclear regions, etc) and/or of fainter spectral components (e.g., broad emission line components, fainter diagnostic lines).