J/MNRAS/509/5467 Galaxy LF with GAMA and KiDS data (Karademir+, 2022)
Galaxy And Mass Assembly (GAMA) z ∼ 0 galaxy luminosity function down to
L ∼ 106 L☉ via clustering based redshift inference.
Karademir G.S., Taylor E.N., Blake C., Baldry I.K., Bellstedt S.,
Bilicki M., Brown M.J.I., Cluver M.E., Driver S.P., Hildebrandt H.,
Holwerda B.W., Hopkins A.M., Loveday J., Phillipps S., Wright A.H.
<Mon. Not. R. Astron. Soc. 509, 5467-5484>
=2022MNRAS.509.5467K 2022MNRAS.509.5467K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Models ; Redshifts ; Magnitudes, absolute ;
Optical ; Photometry ; Spectroscopy
Keywords: methods: data analysis - methods: statistical -
galaxies: distances and redshifts
Abstract:
In this study, we present a new experimental design using
clustering-based redshift inference to measure the evolving galaxy
luminosity function (GLF) spanning 5.5 decades from L ∼ 1011.5 to 106
L☉. We use data from the Galaxy And Mass Assembly (GAMA) survey
and the Kilo-Degree Survey (KiDS). We derive redshift distributions in
bins of apparent magnitude to the limits of the GAMA- KiDS photometric
catalogue: mr ≤ 23; more than a decade in luminosity beyond the
limits of the GAMA spectroscopic redshift sample via clustering-based
redshift inference. This technique uses spatial cross-correlation
statistics for a reference set with known redshifts (in our case, the
main GAMA sample) to derive the redshift distribution for the target
ensemble. For the calibration of the redshift distribution, we use a
simple parametrization with an adaptive normalization factor over the
interval 0.005 < z < 0.48 to derive the clustering redshift results.
We find that the GLF has a relatively constant power-law slope
α ≃ -1.2 for -17 ≤ Mr ≤ -13, and then appears to steepen
sharply for -13 ≤ Mr ≤ -10. This upturn appears to be where
globular clusters (GCs) take over to dominate the source counts as a
function of luminosity. Thus, we have mapped the GLF across the full
range of the z ∼ 0 field galaxy population from the most luminous
galaxies down to the GC scale.
Description:
The galaxy luminosity function (GLF) is a basic descriptor of the
galaxy population and its evolution though the history of the
Universe. GLF measurementsplay a key role in calibrating and
validating theoretical models of galaxy formation and evolution,
(see section 1 Introduction for more details).
First, we rely on high-quality photometry from deep optical imaging to
map the apparent fluxes of the evolving galaxy population. We use
positions and total r-band magnitudes from a GAMA reanalysis of VST
imaging from the KiDS survey. Also, we use the GAMA spectroscopic
redshift survey for trace the large-scale structure across the target
area. GAMA was a multi-year campaign with the 3.9m Anglo Australian
Telescope (AAT) (i.e see section 2 Data and sample selection).
Next, as explained in the section 3 Redshift information from
clustering, clustering-based redshift inferences (cluster-zs) provide
an avenue to statistical redshift information for an ensemble of
target objects, based only on positional information. Cluster-zs work
by cross-correlating, the positions of the target sample with the
positions of a reference sample for which redshifts are known. By
computing the relative strength of the 2D angular cross-correlation
for sub-samples of the reference set binned by redshift with the
target ensemble, it is possible to infer the target redshift
distribution.
For this method we need three data sets (see Section 2). First the
target data set: it consists of objects for which the cluster-zs are
calculated solely using their angular positions on the sky (RA, Dec).
Secondly a reference data set, mapping the cosmic skeleton, is needed.
This set has to consist of objects with accurate measurements of their
full 3D position (RA, Dec., and z). In addition to the two samples
mentioned above, an unclustered random sample, which covers the same
area and the same angular distribution of the reference sample, has to
be generated during the calculation.
Hereafter (refer to the section 4), the goal of this paper is to use
the clustering redshift measurements described in Section 3 to
determine (GLF) the luminosity function for z ∼ 0 galaxies to the
faintest possible limits. In principle, the evolving luminosity
function φ(m|z) can be directly inferred from the observed
bivariate distribution Nm,z plus cosmology. Results of our method is
presented in the section 5 (see figure 9 and 10 in the article).
Finally, we deliver our GLF φ(Mr) data result in the table
glf.dat.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
glf.dat 75 170 Density distribution of the galaxy luminosity
function at z <0.1
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See also:
https://kids.strw.leidenuniv.nl/DR4/ : KiDS DR4
https://www.gama-survey.org/ : GAMA home page
Byte-by-byte Description of file: glf.dat
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Bytes Format Units Label Explanations
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1- 25 E25.19 mag rMag The r-band absolute Magnitude (Mr)
27- 50 E24.19 mag-1/Mpc3 phi Galaxy number density (φM)
52- 75 E24.19 mag-1/Mpc3 e_phi Error in the galaxy number density
(errφM)
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 10-Oct-2024