Characterising the evolving -band luminosity function using the UltraVISTA, CANDELS and HUDF surveys
arXiv:1610.06574 · doi:10.1093/mnras/stw2728
Abstract
We present the results of a new study of the K-band galaxy luminosity function (KLF) at redshifts z<3.75, based on a nested combination of the UltraVISTA, CANDELS and HUDF surveys. The large dynamic range in luminosity spanned by this new dataset (3-4 dex over the full redshift range) is sufficient to clearly demonstrate for the first time that the faint-end slope of the KLF at z>0.25 is relatively steep (-1.3<alpha<-1.5 for a single Schechter function), in good agreement with recent theoretical and phenomenological models. Moreover, based on our new dataset we find that a double Schechter function provides a significantly improved description of the KLF at z<2. At redshifts z>0.25 the evolution of the KLF is remarkably smooth, with little or no evolution evident at faint (M_K>-20.5) or bright magnitudes (M_K<-24.5). Instead, the KLF is seen to evolve rapidly at intermediate magnitudes, with the number density of galaxies at M_K~-23 dropping by a factor of ~5 over the redshift interval 0.25<z<3.75. Motivated by this, we explore a simple description of the evolving KLF based on a double Schechter function with fixed faint-end slopes (alpha_1=-0.5, alpha_2=-1.5) and a shared characteristic magnitude (M_K*). According to this parameterisation, the normalisation of the component which dominates the faint-end of the KLF remains approximately constant, with phi*_2 decreasing by only a factor of ~2 between z~0 and z~3.25. In contrast, the component which dominates the bright end of the KLF at low redshifts evolves dramatically, becoming essentially negligible by z~3. Finally, we note that within this parameterisation, the observed evolution of M_K* between z~0 and z~3.25 is entirely consistent with M_K* corresponding to a constant stellar mass of M*~5x10^10 Msun at all redshifts.
18 pages, 10 figures, accepted for publication in MNRAS
References in corpus (19)
- The UKIRT Infrared Deep Sky Survey (UKIDSS)
- Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
- EAZY: A Fast, Public Photometric Redshift Code
- K-corrections and filter transformations in the ultraviolet, optical, and near infrared
- COSMOS Photometric Redshifts with 30-bands for 2-deg2
- Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
- UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
- The Chandra COSMOS Survey, I: Overview and Point Source Catalog
- The VLA-COSMOS Survey: II. Source Catalog of the Large Project
- The Subaru/XMM-Newton Deep Survey (SXDS) - II. Optical Imaging and Photometric Catalogs
- On the galaxy stellar mass function, the mass-metallicity relation, and the implied baryonic mass function
- Star Formation at From the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH)
- The evolution of the near-IR galaxy Luminosity Function and colour bimodality up to z ~ 2 from the UKIDSS Ultra Deep Survey Early Data Release
- Deep U band and R imaging of GOODS-South: Observations,data reduction and first results
- Near-Infrared and Optical Luminosity Functions from the 6dF Galaxy Survey
- The Hawk-I UDS and GOODS Survey (HUGS): Survey design and deep K-band number counts
- Deconstructing the Galaxy Stellar Mass Function with UKIDSS and CANDELS: the Impact of Colour, Structure and Environment
- z~7-10 Galaxies behind Lensing Clusters: Contrast with Field Search Results
- Luminosity and surface brightness distribution of K-band galaxies from the UKIDSS Large Area Survey