Wednesday, November 30, 2011

1111.6997 (R. Bielby et al.)

The WIRCam Deep Survey I: Counts, colours and mass-functions derived from near-infrared imaging in the CFHTLS Deep Fields    [PDF]

R. Bielby, P. Hudelot, H. J. McCracken, O. Ilbert, E. Daddi, O. Le Fèvre, V. Gonzalez-Perez, J. -P. Kneib, C. Marmo, Y. Mellier, M. Salvato, D. B. Sanders, C. J. Willott
We present a new near-infrared imaging survey in the four CFHTLS deep fields: the WIRCam Deep Survey or "WIRDS". WIRDS comprises extremely deep, high quality (FWHM \approx 0.6") J, H and Ks imaging covering a total effective area of 2.1 square degrees and reaching AB 50% completeness limits of \approx 24.5. We combine our images with the CFHTLS to create a unique eight-band ugrizJHKS photometric catalogues in the four CFHTLS deep fields; these four separate fields allow us to make a robust estimate of the effect of cosmic variance for all our measurements. We use these catalogues in combination with \approx 9,800 spectroscopic redshifts to estimate precise photometric redshifts ({\sigma} < 0.03), galaxy types, star-formation rates and stellar masses for a unique sample of \approx 1.8 million galaxies. Our JHKs number counts are consistent with previous studies. We apply the "BzK" selection to our gzK filter set and find that the star forming BzK selection successfully selects 76% of star-forming galaxies in the redshift range 1.4 < z < 2.5 in our photometric catalogue, based on our photometric redshift measurement. Similarly the passive BzK selection returns 52% of the passive 1.4 < z < 2.5 population identified in the photometric catalogue. We present the mass functions of the total galaxy population as a function of redshift up to z = 2. We show that the GALFORM semi-analytical galaxy formation model can produce a consistent match to the observed mass functions across the mass range log(M/M\odot) \sim 10-11 up to redshifts of z \sim 1.2 - 1.5. All photometric catalogues and images are made publicly available from TERAPIX and CADC.
View original: http://arxiv.org/abs/1111.6997

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