The WIRCam Deep Survey

Abstract

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 ∼ 0.6 ) J, H, and K s imaging covering a total effective area of 2.1 deg 2 and reaching AB 50% completeness limits of ≈24.5. We combine our images with the CFHTLS to create a unique eight-band ugrizJHK S 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 ≈9800 spectroscopic redshifts to estimate precise photometric redshifts (σ Δz/(1+z) 0.03 at i < 25), galaxy types, star-formation rates and stellar masses for a unique sample of ≈1.8 million galaxies. Our JHK s 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 and present fits using double Schechter functions. A mass-dependent evolution of the mass function is seen with the numbers of galaxies with masses of M 10 10.75 still evolving at z 1, but galaxies of higher mass reaching their present day numbers by z ∼ 0.8−1. This is consistent with the present picture of downsizing in galaxy evolution. We compare our results with the predictions of the GALFORM semi-analytical galaxy formation model and find that the simulations provide a relatively successful fit to the observed mass functions at intermediate masses (i.e. 10 log (M/M ) 11). However, as is common with semi-analytical predictions of the mass function, the GALFORM results under-predict the mass function at low masses (i.e. log (M/M ) 10), whilst the fit as a whole degrades beyond redshifts of z ∼ 1.2. All photometric catalogues and images are made publicly available from TERAPIX and CADC.

Hidden starbursts and active galactic nuclei at 0 < z < 4 from theHerschel-VVDS-CFHTLS-D1 field: Inferences on coevolution and feedback

“…The pixel scale of the CFHTLS imaging is 0.186 /pixel and the average seeing for the five bands ranges between 0.7 -0.85 over the entire area of the imaging used for this paper, with progressively better seeing in progressively redder bands. For further details on properties of the CFHTLS-D1 imaging and the reduction process see the CFHTLS TERAPIX website 4 , Ilbert et al (2006), and Bielby et al (2012).…”

“…taken as part of the WIRCam Deep Survey (WIRDS; Bielby et al 2012), a survey designed provide deep JHK s NIR imaging for a large portion of all four CFHTLS fields. In the CFHTLS-D1 field, the one relevant to this paper, the WIRDS imaging covers roughly ∼75% of the area covered by the CFHTLS imaging, reaching 5σ point source completeness limits of 24.2, 24.1, and 24.0 in the J, H, & K s bands, respectively.…”

“…This pixel scale matches that of the CFHTLS imaging and, more importantly, is sufficient to Nyquist sample the 0.6 average seeing achieved by WIRDS at Mauna Kea in the NIR. For a full characterization of the WIRDS survey, as well as full details of the WIRDS imaging properties and reduction see Bielby et al (2012). Additional NIR imaging spanning a portion of both the CFHTLS and WIRDS coverage was drawn from the Spitzer Wide-Area InfraRed Extragalactic survey (SWIRE; Lonsdale et al 2003).…”

A framework for empirical galaxy phenomenology: the scatter in galaxy ages and stellar metallicities

“…All that remains to describe our implementation of passive galaxies completely is to specify our choice of dn/dM⋆. We adopt the observed stellar mass functions of Bielby et al (2012), who use data from the WIRCam Deep Survey and a methodology for deriving stellar masses very similar to that of Brammer et al (2011) and Whitaker et al (2012) to fit results at discrete redshifts from 0.2 < z < 2 with a double- Schechter (1976) function: …”

“…Recent observations have characterized (1) the evolution of stellar mass function (e.g., Bielby et al 2012;Muzzin et al 2013); (2) the bimodal nature of galaxies into quiescent and star-forming to z ∼ 3 (e.g., Brammer et al 2011;Muzzin et al 2013); (3) the evolving correlation between the stellar masses and star formation rates of star-forming systems (e.g., Noeske et al 2007;Daddi et al 2007;Karim et al 2011;Whitaker et al 2012;González et al 2014); (4) a tight "fundamental metallicity relation" (FMR) among stellar mass, star formation rate, and gas-phase metallicity (e.g., Kewley & Ellison 2008;Lara-López et al 2010;Mannucci et al 2010;Andrews & Martini 2013); (6) the structure of cold gas fueling galaxies (e.g., Genel et al 2010); and (6) the environmental influ-⋆ E-mail:jamunoz@physics.ucsb.edu ence on galactic properties (e.g., Peng et al 2010;Pasquali et al 2010;Lin et al 2014). Yet, these various empirical relations beg a theoretical framework that answer questions about their effects on and relative importance in the buildup of stellar mass in the universe.…”