NIR Follow - Up of the VVDS 02 hr Field

We present a new K-band survey covering 623 arcmin 2 in the VVDS 0226-0430 deep field down to a limiting magnitude KVega 20.5. We use the spectroscopic sample extracted from this new K-band catalogue to assess the effectiveness of optical-near infrared color selections in identifying extreme classes of objects at high redshift. 1. The VVDS F02 K-selected sample Near-infrared (NIR) selected samples are ideal tools for studying the process of mass assembly at intermediate/high redshift, thanks to the advantages of NIR with respect to optical selection. Within the context of the VIMOS-VLT Deep Survey (see Garilli et al., Lamareille et al., and Vergani et al., this volume, for additional information on the VVDS), we present a new K-band survey in the VVDS 0226-0430 deep field (F02), already covered by the purely flux-limited VVDS spectroscopic survey (17.5 I AB 24; Le Févre et al. 2005). Deep ancillary photometric data in this field are available through the VVDS (BVRI; McCracken et al. 2003) and the CFHT Legacy Survey (u * g ′ r ′ i ′ z ′). The new K-band data, obtained with SOFI at ESO-NTT, extend those described in Iovino et al. (2005), thus covering a total contiguous area of 623 arcmin 2 to a limiting magnitude K Vega 20.5 (90% completeness). Our photometric catalogue includes 8857 objects down to K Vega 20.25. Galaxy counts are in good agreement with those from the literature. The angular correlation function does not show any peculiarity as a function of magnitude and angular scale and is broadly in agreement with results from the literature. The K-selected spectroscopic sample contains 1792 galaxies with good quality redshifts. A minimal incompleteness in color arises at K V ega > 19.8, as the reddest objects are disfavoured by the I AB 24 limit. For this red tail of the galaxy color distribution we rely on the wide multiwavelength coverage to obtain good quality photometric redshifts following the method adopted in Ilbert et al. (2006). For this purpose, we note that the use of K-band data reduces considerably the percentage of catastrophic errors (see Appendix). A detailed description of this K-band sample is given in Temporin et al. (2007a). Since the VVDS survey is purely flux-limited, this sample is ideal for assessing the effectiveness of different optical-NIR color selections to identify extreme classes of objects like extremely red objects (EROs) and high-redshift galaxies (BzK; Daddi et al. 2004). …