J/ApJ/738/69 SEDs of galaxies at 3.8<z<5 in GOODS (Shim+, 2011)
z ∼ 4 Hα emitters in the Great Observatories Origins Deep Survey: tracing
the dominant mode for growth of galaxies.
Shim H., Chary R.-R., Dickinson M., Lin L., Spinrad H., Stern D., Yan C.-H.
<Astrophys. J., 738, 69 (2011)>
=2011ApJ...738...69S 2011ApJ...738...69S
ADC_Keywords: Galaxies, photometry ; Photometry, HST ; Photometry, infrared ;
Redshifts ; Equivalent widths ; Surveys
Keywords: cosmology: observations - galaxies: evolution -
galaxies: high-redshift - galaxies: starburst
Abstract:
We present evidence for strong Hα emission in galaxies with
spectroscopic redshifts in the range of 3.8<z<5.0 over the Great
Observatories Origins Deep Survey fields. Among 74 galaxies detected
in the Spitzer IRAC 3.6 and 4.5um bands, more than 70% of the galaxies
show clear excess at 3.6um compared to the expected flux density from
stellar continuum only. We provide evidence that this 3.6um excess is
due to Hα emission redshifted into the 3.6um band, and classify
these 3.6um excess galaxies to be Hα emitter (HAE) candidates.
The selection of HAE candidates using an excess in broadband filters
is sensitive to objects whose rest-frame Hα equivalent width
(EW) is larger than 350Å. The Hα inferred star formation
rates (SFRs) of the HAEs range between 20 and 500M☉/yr and are
a factor of ∼6 larger than SFRs inferred from the UV continuum. The
ratio between the Hα luminosity and UV luminosity of HAEs is
also on average larger than that of local starbursts.
Description:
From the various spectroscopic observing programs over the Great
Observatories Origins Deep Survey (GOODS) North and South field
(including Vanzella et al. 2005, Cat. J/A+A/434/53; 2006,
Cat. J/A+A/454/423; 2008, Cat. J/A+A/478/83; Ando et al.
2004ApJ...610..635A 2004ApJ...610..635A), we select galaxies with secure spectroscopic
redshifts between z=3.8 and 5.0. We used the optical-to-MIR merged
photometric catalog over GOODS-South and GOODS-North to obtain
multi-band photometric data for these objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 187 74 Photometry of galaxies at 3.8<z<5.0
table2.dat 91 148 Spectral energy distribution-fitting results
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See also:
II/261 : GOODS initial results (Giavalisco+, 2004)
J/A+A/512/A12 : VLT/VIMOS spectroscopy in GOODS-South field (Balestra+, 2010)
J/A+A/511/A50 : JHks of GOODS-South field (Retzlaff+, 2010)
J/ApJS/187/251 : Ultradeep Ks imaging in the GOODS-N (Wang+, 2010)
J/A+A/478/83 : GOODS-S Field VLT/FORS2 redshifts. III. (Vanzella+, 2008)
J/ApJ/689/687 : GOODS-N spectroscopic survey (Barger+, 2008)
J/ApJ/666/863 : GOODS MIPS early-type galaxies (Van Der Wel+, 2007)
J/A+A/454/423 : GOODS-South Field VLT/FORS2 redshifts. II. (Vanzella+, 2006)
J/A+A/434/53 : GOODS-South Field redshifts (Vanzella+, 2005)
http://irsa.ipac.caltech.edu/data/GOODS/ : NASA/IPAC IRSA GOODS Spitzer data
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Galaxy name (WNNNNN) (G1)
8 A1 --- f_ID [m] Inconsistent SED (1)
10- 11 I2 h RAh Hour of right ascension (J2000)
13- 14 I2 min RAm Minute of right ascension (J2000)
16- 20 F5.2 s RAs Second of right ascension (J2000)
22 A1 --- DE- Sign of declination (J2000)
23- 24 I2 deg DEd Degree of declination (J2000)
26- 27 I2 arcmin DEm Arcminute of declination (J2000)
29- 33 F5.2 arcsec DEs Arcsecond of declination (J2000)
35- 39 F5.3 --- zsp Spectroscopic redshift
41 A1 --- l_Bmag Limit flag on Bmag
42- 46 F5.2 mag Bmag HST/ACS F435W AB magnitude (2)
48- 51 F4.2 mag e_Bmag ? Bmag uncertainty
53- 57 F5.2 mag Vmag HST/ACS F606W AB magnitude (2)
59- 62 F4.2 mag e_Vmag Vmag uncertainty
64- 68 F5.2 mag imag HST/ACS F775W AB magnitude (2)
70- 73 F4.2 mag e_imag imag uncertainty
75- 79 F5.2 mag zmag HST/ACS F850LP AB magnitude (2)
81- 84 F4.2 mag e_zmag zmag uncertainty
86- 90 F5.2 mag F110W ? HST/NICMOS F110W (J-band) AB magnitude (3)
92- 95 F4.2 mag e_F110W ? F110W uncertainty
97-101 F5.2 mag F160W ? HST/NICMOS F160W (H-band) AB magnitude (3)
103-106 F4.2 mag e_F160W ? F160W uncertainty
108 A1 --- l_Jmag Limit flag on Jmag
109-113 F5.2 mag Jmag ? J-band AB magnitude (3)
115-118 F4.2 mag e_Jmag ? Jmag uncertainty
120-124 F5.2 mag Hmag ? H-band AB magnitude (3)
126-129 F4.2 mag e_Hmag ? Hmag uncertainty
131 A1 --- l_Kmag Limit flag on Kmag
132-136 F5.2 mag Kmag ? K-band AB magnitude (3)
138-141 F4.2 mag e_Kmag ? Kmag uncertainty
143-147 F5.2 mag [3.6] Spitzer/IRAC 3.6um-band AB magnitude
149-152 F4.2 mag e_[3.6] uncertainty on [3.6]
154-158 F5.2 mag [4.5] Spitzer/IRAC 4.5um-band AB magnitude
160-163 F4.2 mag e_[4.5] uncertainty on [4.5]
165 A1 --- l_[5.8] Limit flag on 5.8mag
166-170 F5.2 mag [5.8] Spitzer/IRAC 5.8um-band AB magnitude
172-175 F4.2 mag e_[5.8] ? uncertainty on [5.8]
177 A1 --- l_[8.0] Limit flag on 8.0mag
178-182 F5.2 mag [8.0] Spitzer/IRAC 8.0um-band AB magnitude
184-187 F4.2 mag e_[8.0] ? uncertainty on [8.0]
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Note (1): Two of the objects, S15920 and N12074, appear to show multiwavelength
SED that are inconsistent with their quoted redshift and likely have
erroneous spectroscopic redshifts.
Note (2): The optical bands, included in this study, are the HST/ACS F435W,
F606W, F775W, and F850LP (generally referred to as B, V, i, and z)
bands (Giavalisco et al. 2004, Cat. II/261).
Note (3): We derived the NIR photometry of sample galaxies by matching the
sample catalog with the available data from NIR observing programs.
When available, we used HST/NICMOS J110 and H160 fluxes
(Conselice et al. 2011MNRAS.413...80C 2011MNRAS.413...80C; Dickinson 1999, AIP Conf.
Proc. 470, ed. S. Holt & E. Smith (Melville, NY: AIP), 122).
The J-, H-, and K-band magnitudes are the VLT/ISAAC magnitudes for
galaxies in CDF-South (Retzlaff et al. 2010, Cat. J/A+A/511/A50),
while J- and K-band magnitudes are from CFHT/WIRCAM for galaxies in
HDF-North (observations during the years 2006-2009).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Galaxy name (WNNNNN) (G1)
8- 10 A3 --- f_ID [a,b ] Galaxy detected in X-ray/sub-mm (1)
12- 16 F5.3 --- zsp Spectroscopic redshift
18- 22 F5.2 --- chi2 χ2 (see equation (1))
24- 28 F5.2 [Msun] logM Log of stellar mass
30- 33 F4.2 mag E(B-V) E(B-V)
35- 38 I4 Myr Age Stellar population age
40- 43 I4 Myr tau e-folding timescale of star formation τ
45- 49 F5.2 --- beta UV spectral slope β
51- 53 A3 --- Law Extinction law (SB or SMC) (2)
55- 59 F5.2 [10-7W] logLHa ? Log of Hα luminosity
61- 64 F4.2 [10-7W] e_logLHa ? logLHa uncertainty
66- 69 I4 0.1nm EWHa ? Hα equivalent width
71- 74 I4 0.1nm e_EWHa ? EWHa uncertainty
76- 80 F5.1 Msun/yr SFRHa ? Hα star formation rate
82- 85 F4.1 Msun/yr SFRUV UV star formation rate
87- 91 F5.2 --- S3.6 Sch1 (3.6um) IR excess (3)
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Note (1): Flag as follows:
a = X-ray detected active galactic nuclei.
b = Submillimeter galaxy with f850um∼5mJy (Coppin et al.
2009MNRAS.395.1905C 2009MNRAS.395.1905C).
Note (2): For internal reddening of the model galaxy templates, we used two
forms of extinction law: the extinction law for local starbursts
("SB"; Calzetti et al. 2000ApJ...533..682C 2000ApJ...533..682C) and the extinction law for
the Small Magellanic Cloud ("SMC"; Prevot et al. 1984A&A...132..389P 1984A&A...132..389P).
Note (3): The factor Sch1 represents the significance of the Spitzer/IRAC
ch1 (3.6um) excess compared to typical residuals at other wavelengths
from the SED fitting. See Equation (2) in section 3.2 for further
explanations.
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Global notes:
Note (G1): Number NNNNN is from "IDMos" column in Cat. II/261.
Galaxies are in Simbad.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 15-Jan-2013