Title 



The VLT LBG redshift survey : 1 : clustering and dynamics of galaxies at
 
Author 



 
Abstract 



We present the initial imaging and spectroscopic data acquired as part of the Very Large Telescope (VLT) VIMOS Lymanbreak galaxy Survey. UBR (or UBVI) imaging covers five ≈36 × 36 arcmin2 fields centred on bright z > 3 quasistellar objects (QSOs), allowing ≈21 000 2 < z < 3.5 galaxy candidates to be selected using the Lymanbreak technique. We performed spectroscopic followup using VLT VIMOS, measuring redshifts for 1020 z > 2 Lymanbreak galaxies and 10 z > 2 QSOs from a total of 19 VIMOS pointings. From the galaxy spectra, we observe a 625 ± 510 km s−1 velocity offset between the interstellar absorption and Lyman α emissionline redshifts, consistent with previous results. Using the photometric and spectroscopic catalogues, we have analysed the galaxy clustering at z≈ 3. The angular correlation function, w(θ), is well fitted by a double power law with clustering scalelength, r0= 3.19+0.32−0.54 h−1 Mpc and slope γ= 2.45 for r < 1 h−1 Mpc and r0= 4.37+0.43−0.55 h−1 Mpc with γ= 1.61 ± 0.15 at larger scales. Using the redshift sample we estimate the semiprojected correlation function, wp(σ), and, for a γ= 1.8 power law, find r0= 3.67+0.23−0.24 h−1 Mpc for the VLT sample and r0= 3.98+0.14−0.15 h−1 Mpc for a combined VLT+Keck sample. From ξ(s) and ξ(σ, π), and assuming the above ξ(r) models, we find that the combined VLT and Keck surveys require a galaxy pairwise velocity dispersion of ≈700 km s−1, higher than ≈400 km s−1 assumed by previous authors. We also measure a value for the gravitational growth rate parameter of β(z= 3) = 0.48 ± 0.17, again higher than that previously found and implying a low value for the bias of b= 2.06+1.1−0.5. This value is consistent with the galaxy clustering amplitude which gives b= 2.22 ± 0.16, assuming the standard cosmology, implying that the evolution of the gravitational growth rate is also consistent with Einstein gravity. Finally, we have compared our Lymanbreak galaxy clustering amplitudes with lower redshift measurements and find that the clustering strength is not inconsistent with that of lowredshift L* spirals for simple longlived galaxy models.   
Language 



English
 
Source (journal) 



Monthly notices of the Royal Astronomical Society.  Oxford  
Publication 



Oxford : 2011
 
ISSN 



00358711
 
Volume/pages 



414:1(2011), p. 227
 
ISI 



000292141600023
 
Full text (Publisher's DOI) 


  
