Day 386

Friday.

1303.2601
Evidence for two distinct populations of type Ia supernovae
Wang, wang, Filippenko, Zhang, Zhao

The spectral diversity ofSNIa tied to their birthplace environments.  Find: those with high-velocit ejecta are substantially more concentrated in the inner and brighter regions of their host galaxies than are normal-velocity SNIa.  The former tend to inhabit larger and more-luminous hosts.  THese results suggest that high-velocity SNIa likely originate from relatively younger and more metal-rich progenitors than normal-velocity SNIa, and are restricted to galaxies with substantial chemical evolution.

1303.2623
The VIMOS public extragalactic redshift survey (VIPERS).  An unprecedented view of galaxies and large-scale structure at 0.5<z<1.2
Guzzo et al

Construction and general features of VIPERS: aim of building a spec sample of 100k galaxies with i_AB<22.5 and 0.5<z<1.5.  The survey covers a total area of 24 deg^2 within W1 and W4 fields.  VIPERS is designed to address a broad range of problems in LSS and galaxy evolution, thanks to a unique combination of volume (5e7 [Mpc/h]^3) and sampling rate (40%), comparable to state-of-the-art surveys of local universe, together with extensive multi-band optical and NIR photometry.  Present survey design, selection of the source catalogue and the development of the spectro observations.  Discuss in detail the overall selection function that results from the combination of the different constituents of the project: masks from parent photometric sample, spectroscopic instrumental footprint, weights needed to account for the sampling and the success rates of the observations.  Use catalogue of 53k galaxy redshifts for PDR-1, provide assessment of the quality of the spectroscopic data.  Present a map showing the LS distribution of galaxies between 5 and 8 billion years ago.