J/ApJ/835/113 Galaxies ≳6 from the Hubble Frontier Fields (Livermore+, 2017)
Directly observing the galaxies likely responsible for reionization.
Livermore R.C., Finkelstein S.L., Lotz J.M.
<Astrophys. J., 835, 113-113 (2017)>
=2017ApJ...835..113L 2017ApJ...835..113L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Redshifts
Keywords: galaxies: high-redshift; galaxies: luminosity function, mass function;
dark ages, reionization, first stars
Abstract:
We report a new analysis of the Hubble Frontier Fields clusters
Abell2744 and MACS 0416 using wavelet decomposition to remove the
cluster light, enabling the detection of highly magnified (>50x)
galaxies a factor of 10x fainter in luminosity than previous studies.
We find 167 galaxies at z≳6, and with this sample we are able to
characterize the UV luminosity function to MUV=-12.5 at z∼6, -14 at
z∼7, and -15 at z∼8. We find a steep faint-end slope (α< -2),
and with our improved statistics at the faint end we reduce the
fractional uncertainty on α to <2% at z∼6-7 and 4% at z∼8. We
also investigate the systematic uncertainty due to the lens modeling
by using every available lens model individually and comparing the
results; this systematic fractional uncertainty on α is <4% at
all redshifts. We now directly observe galaxies in the luminosity
regime where some simulations predict a change in the faint-end slope
of the luminosity function, yet our results provide statistically very
strong evidence against any turnover in the luminosity range probed,
more consistent with simulations in which stars form in lower-mass
halos. Thus, we find strong support for the extension of the steep
luminosity function to MUV=-13 at z>6, consistent with the number of
faint galaxies needed to reionize the universe under standard
assumptions.
Description:
The data comprise two lensing clusters observed with the Advanced
Camera for Surveys (ACS) and WFC3 on HST as part of the Hubble
Frontier Fields (HFF) program. The clusters are observed in seven
filters (F435W, F606W, F814W, F105W, F125W, F140W and F160W) and the
drizzled science images and inverse variance weight maps were publicly
released on the HFF Web site.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table7.dat 85 105 Catalog of the z∼6 sample
table8.dat 85 40 Catalog of the z∼7 sample
table9.dat 85 16 Catalog of the z∼8 sample
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See also:
J/ApJ/756/164 : UV galaxies in CANDELS from z=8 to z=4 (Finkelstein+, 2012)
J/ApJ/762/L30 : CLASH: MCS J0416.1-2403 strong lensing analysis (Zitrin+, 2013)
J/ApJ/793/115 : UV-continuum slopes beta for z∼4-8 galaxies (Bouwens+, 2014)
J/MNRAS/443/1549 : MACSJ0416.1-2403 strong-lensing analysis (Jauzac+, 2014)
J/MNRAS/444/268 : HST Frontier Fields clusters (Richard+, 2014)
J/ApJ/800/18 : HST/WFC3 observations of z∼7-8 galaxies in A2744 (Atek+, 2015)
J/ApJ/803/34 : z∼4-10 galaxies from HST legacy fields (Bouwens+, 2015)
J/ApJ/810/71 : UV mag of candidate galaxies at 3~<z~<8.5 (Finkelstein+, 2015)
J/MNRAS/452/1437 : Abell 2744 strong-lensing analysis (Jauzac+, 2015)
J/ApJ/811/29 : GLASS. IV. Lensing cluster Abell 2744 (Wang+, 2015)
J/A+A/590/A31 : ASTRODEEP Frontier Fields Catalogues (Merlin+, 2016)
http://archive.stsci.edu/pub/hlsp/frontier/ : Hubble Frontier Field data
http://www.stsci.edu/hst/campaigns/frontier-fields/Lensing-Models : Frontier
Field lensing models
Byte-by-byte Description of file: table[789].dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID Identifier
17- 25 F9.6 deg RAdeg Right ascension in decimal degrees (J2000)
27- 36 F10.6 deg DEdeg Declination in decimal degrees (J2000)
38- 41 F4.2 --- z [5.3/8.9] Photometric redshift
43- 46 F4.2 --- e_z [0.09/3.1] Negative error in z (1)
48- 51 F4.2 --- E_z [0.04/2]? Positive error in z (1)
53- 57 F5.1 --- mu [1.2/110] Magnification (2)
59- 62 F4.1 --- e_mu [0.1/58] Negative error in mu
64- 68 F5.1 --- E_mu [0/690] Positive error in mu
70- 75 F6.2 mag M1500 [-20.4/-12.4] Intrinsic rest-frame UV AB
magnitude
77- 80 F4.2 mag e_M1500 [0.1/4.1] Negative error in M1500 (3)
82- 85 F4.2 mag E_M1500 [0.2/0.8] Positive error in M1500 (3)
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Note (1): The errors given encompass the 68% confidence interval of the photo-z.
Note (2): The magnification given is the median and interquartile range from all
lens models of the clusters updated after the Frontier Fields data
were obtained.
Note (3): The errors on the intrinsic magnitudes incorporate the errors on the
measured fluxes and the magnification uncertainty.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 06-Oct-2017