J/ApJ/780/34 H160-selected catalog of galaxies in the HUDF (Lundgren+, 2014)
Tracing the mass growth and star formation rate evolution of massive galaxies
from z∼6 to z∼1 in the Hubble Ultra-Deep Field.
Lundgren B.F., van Dokkum P., Franx M., Labbe I., Trenti M., Bouwens R.,
Gonzalez V., Illingworth G., Magee D., Oesch P., Stiavelli M.
<Astrophys. J., 780, 34 (2014)>
=2014ApJ...780...34L 2014ApJ...780...34L
ADC_Keywords: Galaxy catalogs ; Photometry, HST ; Photometry, infrared ;
Redshifts
Keywords: galaxies: evolution - galaxies: formation -
galaxies: fundamental parameters - galaxies: high-redshift -
galaxies: stellar content
Abstract:
We present an analysis of an H160-selected photometric catalog of
galaxies in the Hubble Ultra-Deep Field, using imaging from the
WFC3/IR camera on the Hubble Space Telescope in combination with
archival ultraviolet, optical, and near-infrared imaging. Using these
data, we measure the spectral energy distributions of ∼1500 galaxies
to a limiting H160 magnitude of 27.8, from which we fit photometric
redshifts and stellar population estimates for all galaxies with
well-determined Spitzer IRAC fluxes, allowing for the determination of
the cumulative mass function within the range 1<z<6. By selecting
samples of galaxies at a constant cumulative number density, we are
able to explore the coevolution of stellar masses and star formation
rates (SFRs) for progenitor galaxies and their descendants from z∼6.
We find a steady increase in the SFRs of galaxies at constant number
density from z∼6 to z∼3, accompanied by gradually declining specific
star formation rates (sSFRs) during this same period. The peak epoch
of star formation is also found to shift to later times for galaxies
with increasing number densities, in agreement with the expectations
from cosmic downsizing. The observed SFRs can fully account for the
mass growth to z∼2 among galaxies with cumulative number densities
greater than 10-3.5Mpc-3. For galaxies with a lower constant
number density (higher mean mass), we find the observed stellar masses
are ∼three times greater than that which may be accounted for by the
observed star formation alone at late times, implying that growth from
mergers plays an important role at z<2. We additionally observe a
decreasing sSFR, equivalent to approximately one order of magnitude,
from z∼6 to z∼2 among galaxies with number densities less than
10-3.5Mpc3, along with significant evidence that at any redshift
the sSFR is higher for galaxies at higher number density. The
combination of these findings can qualitatively explain the previous
findings of a specific star formation rate plateau at high redshift.
Tracing the evolution of the fraction of quiescent galaxies for
samples matched in cumulative number density over this redshift range,
we find no unambiguous examples of quiescent galaxies at z>4.
Description:
The Hubble Ultra-Deep Field (HUDF; Beckwith et al. 2006, cat.
J/AJ/132/1729) is an 11 arcmin2 region of the sky within the
GOODS-South field, centered at 3h32m38.5s -27d47'0.0''.
The galaxies we examine have been selected from new H160-band
imaging from the ultra-deep, near-IR WFC3/IR observations in the main
HUDF field, part of the 192-orbit HUDF09 program (PI Illingworth: G0
11563). The HUDF09 program includes WFC3/IR images in three filter
bands: Y105, J125, and H160.
Imaging of the HUDF obtained with the ACS instrument on HST includes
observations in four optical filter bands: F435W, F606W, F775W, and
F850LP. The observations were obtained in a total of 400 orbits
between 2003 September and 2004 January (Beckwith et al. 2006, cat.
J/AJ/132/1729).
We include deep U-band imaging taken with the VIMOS instrument on the
Very Large Telescope's (VLT's) Melipal Unit Telescope at Cerro Paranal
Observatory in Chile. These data were obtained by the European
Southern Observatory large program 168.A-0485 (PI C. Cesarsky), as
part of the Great Observatories Origins Deep Survey (GOODS). The
individual frames contributing to the co-added image were obtained in
service mode between 2004 August and 2006 October.
The Ks-band photometry in this work has been extracted from a
combination of images taken with the Infrared Spectrometer and Array
Camera (ISAAC) mounted on the Antu Unit Telescope of the VLT and the
PANIC near-IR camera on the 6.5m Magellan telescopes. The VLT/ISAAC
exposures were taken in two programs (ESO program 73.A-0764; PI I.
Labbe), one consisting of 8hr on the GOODS Chandra Deep Field South
and another 15hr exposure in the UDF.
Wae include the super-deep observations from the GOODS-S Field, which
were obtained using the Infrared Array Camera (IRAC) on the Spitzer
Space Telescope taken as part of the Spitzer Legacy Program. We
include imaging from channels 1 and 2, which are centered on
wavelengths of 3.6µm and 4.5µm, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 304 1553 Photometric catalog
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
II/258 : Hubble Ultra Deep Field Catalog (UDF) (STScI, 2004)
J/ApJ/735/86 : NEWFIRM MBS: photometric catalogs (Whitaker+, 2011)
J/AJ/135/1624 : PEARS emission-line galaxies (Straughn+, 2008)
J/ApJ/682/985 : FIREWORKS photometry of GOODS CDF-S (Wuyts+, 2008)
J/ApJ/655/51 : HDFS IRAC observations of 2<z<3.5 galaxies (Wuyts+, 2007)
J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)
J/AJ/125/1107 : Ultra-deep near-IR observation in HDF-S (Labbe+, 2003)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Galaxy [1/1635] Unique object number (ID)
6- 12 F7.4 0.36uJy SU38 VLT/VIMOS U38 band flux density (FU38) (1)
14- 19 F6.4 0.36uJy e_SU38 Error in SU38 (eFU38) (1)
21- 27 F7.4 0.36uJy SF435W HST/ACS F435W band flux density (FF1) (1)
29- 34 F6.4 0.36uJy e_SF435W Error in SF435W (eFF1) (1)
36- 42 F7.4 0.36uJy SF606W HST/ACS F606W band flux density (FF4) (1)
44- 49 F6.4 0.36uJy e_SF606W Error in SF606W (eFF4) (1)
51- 57 F7.4 0.36uJy SF775W HST/ACS F775W band flux density (FF6) (1)
59- 64 F6.4 0.36uJy e_SF775W Error in SF775W (eFF6) (1)
66- 73 F8.4 0.36uJy SF850LP HST/ACS F850LP band flux density (FF7) (1)
75- 80 F6.4 0.36uJy e_SF850LP Error in SF850LP (eFF7) (1)
82- 89 F8.4 0.36uJy SF105W HST/WFC3 F105W band flux density (FF202) (1)
91- 96 F6.4 0.36uJy e_SF105W Error in SF105W (eFF202) (1)
98-105 F8.4 0.36uJy SF125W HST/WFC3 F125W band flux density (FF203) (1)
107-112 F6.4 0.36uJy e_SF125W Error in SF125W (eFF203) (1)
114-121 F8.4 0.36uJy SF160W HST/WFC3 F160W band flux density (FF205) (1)
123-128 F6.4 0.36uJy e_SF160W Error in SF160W (eFF205) (1)
130-140 F11.4 0.36uJy SKs ?=-99999 ISAAC/PANIC Ks band flux density
(ISAAC=Infrared Spectrometer and Array
Camera) (FF37) (1)
142-152 F11.4 0.36uJy e_SKs ?=-99999.0000 Error in SKs (eFF37) (1)
154-164 F11.4 0.36uJy S3.6 ?=-99999 Spitzer/IRAC 3.6µm band flux
density (FF18) (1)
166-176 F11.4 0.36uJy e_S3.6 ?=-99999.0000 Error in S3.6 (eFF18) (1)
178-188 F11.4 0.36uJy S4.5 ?=-99999.0000 Spitzer/IRAC 4.5µm band
flux density (FF19) (1)
190-200 F11.4 0.36uJy e_S4.5 ?=-99999.0000 Error in S4.5 (eFF19) (1)
202-210 F9.6 deg RAdeg Right Acsension in decimal degrees (J2000)
(R.A.)
212-221 F10.6 deg DEdeg Declination in decimal degrees (J2000) (decl)
223-229 F7.2 pix Xpix X image pixel coordinate
231-237 F7.2 pix Ypix Y image pixel coordinate
239 I1 --- Blend [4/7] SExtractor blend flag (BFlag) (2)
240-244 A5 --- --- [.000]
246-251 F6.4 --- Weight [0/1] Weight of the F160W exposure (3)
253-259 F7.4 pix Rad [4/56] SExtractor F160W auto aperture radius
(aprad) (2)
261-266 F6.4 --- Corr [1/1.16] Factor of aperture correction
to total (apcor)
268-275 F8.4 --- zsp [0.1/5.5]?=-99 Previous spectroscopic redshift
(zspec) (4)
277-284 F8.4 --- zph [0.1/3.5]?=-99 Previous best photometric
redshift (zph) (5)
286-290 F5.3 --- zpk [0.02/9.8] Peak of the EAZY redshift
probability distribution P(z) (zpeak) (6)
292-296 F5.3 --- e_zpk Lower 1σ limit on zpk (ezpeak)
298-302 F5.3 --- E_zpk Upper 1σ limit on zpk (Ezpeak)
304 I1 --- use [1] Use flag (0 indicates catastrophic blend
or artifact (UFlag) (7)
-------------------------------------------------------------------------------
Note (1): In units of 0.3631µJy. The catalog fluxes can be converted to total
magnitudes via m=25-2.5log(Fn) where Fn is the total flux density in
each filter for the object with a magnitude m, normalized to a zero point
of 25 in the AB system, corresponding to a flux density of
3.631x10-30erg/s/Hz/cm2 (=3.361x10-33W/m2/Hz and 1Jy=10-26W/m2/Hz).
Note (2): Source extraction output parameters from SExtractor (Bertin & Arnouts,
1996A&AS..117..393B 1996A&AS..117..393B) determined using the H160 detection image.
Note (3): Fraction of maximum exposure in the H160 image at the center of
each object, as determined using the H160 weight map.
Note (4): Drawn from the GRAPES (Pirzkal et al., 2004ApJS..154..501P 2004ApJS..154..501P) and
PEARS (Straughn et al. 2008, cat. J/AJ/135/1624) catalogs.
Note (5): Refers to redshifts included in the FIREWORKS catalog (Wuyts et al.
2008, cat. J/ApJ/682/985).
Note (6): For each object, the EAZY code (Brammer et al., 2008ApJ...686.1503B 2008ApJ...686.1503B)
produces a redshift probability distribution, which can be used to
determine the photometric redshift in multiple ways. The discrete peak of
this distribution is returned as zpeak. See Section 3.4 for more details.
Note (7): After visual inspection, 20 objects have been excluded from the
analysis in this work due to their catastrophic proximity to bright
objects, edges, or other artifacts.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 28-Jan-2015