Galaxy and Mass Assembly (GAMA): ugriz galaxy luminosity functions (original) (raw)
Related papers
The B ‐Band Luminosity Function of Red and Blue Galaxies up to z = 3.5
The Astrophysical Journal, 2005
We have explored the redshift evolution of the luminosity function of red and blue galaxies up to z = 3.5. This was possible joining a deep I band composite galaxy sample, which includes the spectroscopic K20 sample and the HDFs samples, with the deep H AB = 26 and K AB = 25 samples derived from the deep NIR images of the Hubble Deep Fields North and South, respectively. About 30% of the sample has spectroscopic redshifts and the remaining fraction wellcalibrated photometric redshifts. This allowed to select and measure galaxies in the rest-frame blue magnitude up to z ∼ 3 and to derive the redshift evolution of the B-band luminosity function of galaxies separated by their rest-frame U − V color or specific (i.e. per unit mass) star-formation rate. The class separation was derived from passive evolutionary tracks or from their observed bimodal distributions. Both distributions appear bimodal at least up to z ∼ 2 and the locus of red/early galaxies is clearly identified up to these high redshifts. Both luminosity and density evolutions are needed to describe the cosmological behaviour of the red/early and blue/late populations. The density evolution is greater for the early population with a decrease by one order of magnitude at z ∼ 2 − 3 with respect to the value at z ∼ 0.4. The luminosity densities of the early and late type galaxies with M B < −20.6 appear to have a bifurcation at z > 1. Indeed while star-forming galaxies slightly increase or keep constant their luminosity density, "early" galaxies decrease in their luminosity density by a factor ∼ 5 − 6 from z ∼ 0.4 to z ∼ 2.5 − 3. A comparison with one of the latest versions of the hierarchical CDM models shows a broad agreement with the observed number and luminosity density evolutions of both populations.
The Luminosity Density of Red Galaxies
Astronomical Journal, 2002
A complete sample of 7.7times1047.7\times 10^47.7times104 galaxies with five-band imaging and spectroscopic redshifts from the Sloan Digital Sky Survey is used to determine the fraction of the optical luminosity density of the Local Universe (redshifts 0.02<z<0.220.02<z<0.220.02<z<0.22) emitted by red galaxies. The distribution in the space of rest-frame color, central surface brightness, and concentration is shown to be highly clustered and bimodal; galaxies fall primarily into one of two distinct classes. One class is red, concentrated and high in surface brightness; the other is bluer, less concentrated, and lower in central surface brightness. Elliptical and bulge-dominated galaxies preferentially belong to the red class. Even with a very restrictive definition of the red class that includes limits on color, surface brightness and concentration, the class comprises roughly one fifth of the number density of galaxies more luminous than 0.05Lstar0.05 \Lstar0.05Lstar and produces two fifths of the total cosmic galaxy luminosity density at 0.7mathrmmum0.7 \mathrm{\mu m}0.7mathrmmum. The natural interpretation is that a large fraction of the stellar mass density of the Local Universe is in very old stellar populations.
Radius‐dependent Luminosity Evolution of Blue Galaxies in GOODS‐N
The Astrophysical Journal, 2007
We examine the radius-luminosity (R-L) relation for blue galaxies in the Team Keck Redshift Survey (TKRS) of GOODS-N. We compare with a volume-limited, Sloan Digital Sky Survey sample and find that the R-L relation has evolved to lower surface brightness since z = 1. Based on the detection limits of GOODS this can not be explained by incompleteness in low surface-brightness galaxies. Number density arguments rule out a pure radius evolution. It can be explained by a radius dependent decline in B-band luminosity with time. Assuming a linear shift in M B with z, we use a maximum likelihood method to quantify the evolution. Under these assumptions, large (R 1/2 > 5 kpc), and intermediate sized (3 < R 1/2 < 5 kpc) galaxies, have experienced ∆M B = 1.53(−0.10, +0.13) and 1.65(−0.18, +0.08) magnitudes of dimming since z = 1. A simple exponential decline in star formation with an e-folding time of 3 Gyr can result in this amount of dimming. Meanwhile, small galaxies, or some subset thereof, have experienced more evolution, 2.55(±0.38) magnitudes. This factor of ten decline in luminosity can be explained by sub-samples of starbursting dwarf systems that fade rapidly, coupled with a decline in burst strength or frequency. Samples of bursting, luminous, blue, compact galaxies at intermediate redshifts have been identified by various previous studies. If there has been some growth in galaxy size with time, these measurements are upper limits on luminosity fading. Subject headings: galaxies: evolution-galaxies: fundamental parameters-galaxies: starburstcatalogs 2.5. Selecting Blue Galaxies Recent studies (Blanton et al. 2003A; Bell et al. 2004; Weiner et al. 2005) demonstrate that galaxy populations are bimodal in optical color. The color-magnitude diagram for TKRS also shows that galaxies fall into two regions in color space, blue galaxies and red sequence
The CANADA-FRANCE REDSHIFT SURVEY VI: Evolution of the galaxy luminosity function to z ~ 1
1995
The cosmic evolution of the field galaxy population has been studied out to a redshift of z ~ 1 using a sample of 730 I-band selected galaxies, of which 591 have secure redshifts with median ~ 0.56. The tri-variate luminosity function phi(M,color,z) shows unambiguously that the population evolves and that this evolution is strongly differential with color and, less strongly, with luminosity. The luminosity function of red galaxies shows very little change in either number density or luminosity over the entire redshift range 0 < z < 1. In contrast, the luminosity function of blue galaxies shows substantial evolution at redshifts z > 0.5. By 0.5 < z < 0.75, the blue luminosity function appears to have uniformly brightened by approximately 1 mag. At higher redshifts, the evolution appears to saturate at the brightest magnitudes but continues at fainter levels leading to a steepening of the luminosity function. A significant excess of galaxies relative to the Loveday et al. (1992) local luminosity function is seen at low redshifts z < 0.2 around M(B) ~ -18$ and these galaxies may possibly represent the descendants of the evolving blue population seen at higher redshifts. The changes seen in the luminosity function are also apparent in color-magnitude diagrams constructed at different epochs and in the V/V_max statistic computed as a function of spectral type. Finally, it is argued that the picture of galaxy evolution presented here is consistent with the very much smaller samples of field galaxies that have been selected in other wavebands, and with the results of studies of galaxies selected on the basis of Mg II 2799 absorption.
Astrophysical Journal, 2009
We present the color-magnitude and color-stellar mass diagrams for galaxies with z phot 2, based on a K (AB) < 22 catalog of the 1 2 × 1 2 • Extended Chandra Deep Field South (ECDFS) from the MUltiwavelength Survey by Yale-Chile (MUSYC). Our main sample of 7840 galaxies contains 1297 M * > 10 11 M ⊙ galaxies in the range 0.2 < z phot < 1.8. We show empirically that this catalog is approximately complete for M * > 10 11 M ⊙ galaxies for z phot < 1.8. For this mass-limited sample, we show that the locus of the red sequence color-stellar mass relation evolves as ∆(u − r) ∝ (−0.44 ± 0.02) z phot for z phot 1.2. For z phot 1.3, however, we are no longer able to reliably distinguish red and blue subpopulations from the observed color distribution; we show that this would require much deeper near infrared (NIR) data. At 1.5 < z phot < 1.8, the comoving number density of M * > 10 11 M ⊙ galaxies is ≈ 50% of the local value, with a red fraction of ≈ 33 %. Making a parametric fit to the observed evolution, we find n tot (z) ∝ (1 + z phot ) −0. 52±0.12(±0.20) . We find stronger evolution in the red fraction: f red (z) ∝ (1 + z phot ) −1. 17±0.18(±0.21) . Through a series of sensitivity analyses, we show that the most important sources of systematic error are: 1. systematic differences in the analysis of the z ≈ 0 and z ≫ 0 samples; 2. systematic effects associated with details of the photometric redshift calculation; and 3. uncertainties in the photometric calibration. With this in mind, we show that our results based on photometric redshifts are consistent with a completely independent analysis which does not require redshift information for individual galaxies. Our results suggest that, at most, 1/5 of local red sequence galaxies with M * > 10 11 M ⊙ were already in place at z ∼ 2.
The Evolution of the Galaxy Luminosity Function in the Rest-Frame Blue Band up to z =3.5
The Astrophysical Journal, 2003
We present an estimate of the cosmological evolution of the field galaxy luminosity function (LF) in the rest frame 4400Å B-band up to redshift z = 3.5. To this purpose, we use a composite sample of 1541 I-selected galaxies selected down to I AB = 27.2 and 138 galaxies selected down to K AB = 25 from groundbased and HST multicolor surveys, most notably the new deep JHK images in the Hubble Deep Field South (HDF-S) taken with the ISAAC instrument at the ESO-VLT telescope. About 21% of the sample has spectroscopic redshifts, and the remaining fraction well calibrated photometric redshifts. The resulting blue LF shows little density evolution at the faint end with respect to the local values, while at the bright end (M B (AB) < −20) a brightening increasing with redshift is apparent with respect to the local LF. Hierarchical CDM models overpredict the number of faint galaxies by a factor ∼ 3 at z ≃ 1. At the bright end the predicted LFs are in reasonable agreement only at low and intermediate redshifts (z ≃ 1), but fail to reproduce the pronounced brightening observed in the high redshift (z ∼ 2 − 3) LF. This brightening could mark the epoch where a major star formation activity is present in the galaxy evolution.
Evolution of the Galaxy Luminosity Function for Redshift and Density Environment at 0.03
The Astrophysical Journal, 2006
Using galaxy sample observed by the BATC large-field multi-color sky survey and galaxy data of SDSS in the overlapped fields, we study the dependence of the restframe r-band galaxy luminosity function on redshift and on large-scale environment. The large-scale environment is defined by isodensity contour with density contrast δρ/ρ. The data set is a composite sample of 69,671 galaxies with redshifts 0.03 < z < 0.5 and r < 21.5 mag. The redshifts are composed by three parts: 1) spectroscopic redshifts in SDSS for local and most luminous galaxies; 2) 20-color photometric redshifts derived from BATC and SDSS; 3) 5-color photometric redshifts in SDSS. We find that the faint-end slope α steepens slightly from −1.21 at z ∼ 0.06 to −1.35 at z ∼ 0.4, which is the natural consequence of the hierarchical formation of galaxies. The luminosity function also differs with different environments. The value of α changes from −1.21 at underdense regions to −1.37 at overdense regions and the corresponding M * brightens from −22.26 to −22.64. This suggests that the fraction of faint galaxies is larger in high density regions than in low density regions.
The Astrophysical Journal, 2006
Using the deep multi-wavelength MUSYC, GOODS, and FIRES surveys we construct a stellar mass-limited sample of galaxies at 2 < z < 3. The sample comprises 294 galaxies with M > 10 11 M ⊙ distributed over four independent fields with a total area of almost 400 arcmin 2 . The mean number density of massive galaxies in this redshift range ρ(M > 10 11 M ⊙ ) = (2.2 ± 0.6) × 10 −4 h 3 70 Mpc −3 . We present median values and 25 th and 75 th percentiles for the distributions of observed R AB magnitudes, observed J − K s colors, and rest-frame ultra-violet continuum slopes, M/L V ratios, and U − V colors. The galaxies show a large range in all these properties. The "median galaxy" is faint in the observer's optical (R AB = 25.9), red in the observed near-IR (J − K s = 2.48), has a rest-frame UV spectrum which is relatively flat in F λ (β = −0.4), and rest-frame optical colors resembling those of nearby spiral galaxies (U −V = 0.62). We determine which galaxies would be selected as Lyman break galaxies (LBGs) or Distant Red Galaxies (DRGs, having J − K s > 2.3) in this mass-limited sample. By number DRGs make up 69 % of the sample and LBGs 20 %, with a small amount of overlap. By mass DRGs make up 77 % and LBGs 17 %. Neither technique provides a representative sample of massive galaxies at 2 < z < 3 as they only sample the extremes of the population. As we show here, multi-wavelength surveys with high quality photometry are essential for an unbiased census of massive galaxies in the early Universe. The main uncertainty in this analysis is our reliance on photometric redshifts; confirmation of the results presented here requires extensive near-infrared spectroscopy of optically-faint samples.
The DEEP2 galaxy redshift survey: evolution of the colour-density relation at 0.4 < z < 1.35
Monthly Notices of the Royal Astronomical Society, 2007
Using a sample of 19,464 galaxies drawn from the DEEP2 Galaxy Redshift Survey, we study the relationship between galaxy color and environment at 0.4 < z < 1.35. We find that the fraction of galaxies on the red sequence depends strongly on local environment out to z > 1, being larger in regions of greater galaxy density. At all epochs probed, we also find a small population of red, morphologically early-type galaxies residing in regions of low measured overdensity. The observed correlations between the red fraction and local overdensity are highly significant, with the trend at z > 1 detected at a greater than 5σ level. Over the entire redshift regime studied, we find that the color-density relation evolves continuously, with red galaxies more strongly favoring overdense regions at low z relative to their red-sequence counterparts at high redshift. At z 1.3, the red fraction only weakly correlates with overdensity, implying that any color dependence to the clustering of ∼ L * galaxies at that epoch must be small. Our findings add weight to existing evidence that the build-up of galaxies on the red sequence has occurred preferentially in overdense environments (i.e., galaxy groups) at z 1.5. Furthermore, we identify the epoch (z ∼ 2) at which typical ∼ L * galaxies began quenching and moved onto the red sequence in significant number. The strength of the observed evolutionary trends at 0 < z < 1.35 suggests that the correlations observed locally, such as the morphology-density and color-density relations, are the result of environment-driven mechanisms (i.e., "nurture") and do not appear to have been imprinted (by "nature") upon the galaxy population during their epoch of formation.
2006
We examine the radius-luminosity (R-L) relation for blue galaxies in the Team Keck Redshift Survey (TKRS) of GOODS-N. We compare with a volume-limited, Sloan Digital Sky Survey sample and find that the R-L relation has evolved to lower surface brightness since z = 1. Based on the detection limits of GOODS this can not be explained by incompleteness in low surface-brightness galaxies. Number density arguments rule out a pure radius evolution. It can be explained by a radius dependent decline in B-band luminosity with time. Assuming a linear shift in MB with z, we use a maximum likelihood method to quantify the evolution. Under these assumptions, large (R 1/2> 5 kpc), and intermediate sized (3 < R 1/2 < 5 kpc) galaxies, have experienced ∆MB = 1.53(−0.10, +0.13) and 1.65(−0.18, +0.08) magnitudes of dimming since z = 1. A simple exponential decline in star formation with an e-folding time of 3 Gyr can result in this amount of dimming. Meanwhile, small galaxies, or some subset t...