J/ApJ/753/95 LAE galaxies in the ECDF-S at z∼2.1 and z∼3.1 (Bond+, 2012)
Evolution in the continuum morphological properties of Lyα-emitting
galaxies from z = 3.1 to z = 2.1.
Bond N.A., Gawiser E., Guaita L., Padilla N., Gronwall C., Ciardullo R.,
Lai K.
<Astrophys. J., 753, 95 (2012)>
=2012ApJ...753...95B 2012ApJ...753...95B
ADC_Keywords: Galaxies, optical ; Ultraviolet ; Redshifts ; Surveys
Keywords: cosmology: observations; galaxies: formation; galaxies: high-redshift;
galaxies: structure
Abstract:
We present a rest-frame ultraviolet morphological analysis of 108
z∼2.1 Lyα emitters (LAEs) in the Extended Chandra Deep Field
South and compare it to a similar sample of 171 LAEs at z∼3.1. Using
Hubble Space Telescope images from the Galaxy Evolution from
Morphology and SEDs survey, Great Observatories Origins Deep Survey,
and Hubble Ultradeep Field, we measure size and photometric component
distributions, where photometric components are defined as distinct
clumps of UV-continuum emission. At both redshifts, >80% of LAEs have
observed half-light radii <2kpc, but the median half-light radius
rises from 0.95±0.04kpc at z=3.1 to 1.41±0.14kpc at z=2.1. A
similar evolution is seen in the sizes of individual rest-UV
components, but there is no evidence for evolution in the number of
multi-component systems. In the z=2.1 sample, we see clear
correlations between the size of an LAE and other physical properties
derived from its spectral energy distribution (SED). LAEs are found to
be larger for galaxies with higher stellar mass, star formation rate,
and dust obscuration, but there is no evidence for a trend between
equivalent width and half-light radius at either redshift. The
presence of these correlations suggests that a wide range of objects
are being selected by LAE surveys at z∼2, including a significant
fraction of objects for which a massive and moderately extended
population of old stars underlies the young starburst giving rise to
the Lyα emission.
Description:
We use three LAE samples in our analysis, including the equivalent
width complete subsample of z=2.1 LAEs identified by Guaita et al.
(2010ApJ...714..255G 2010ApJ...714..255G), the flux-limited sample of z∼3.1 LAEs of
Gronwall et al. (2007, Cat. J/ApJ/667/79), and of z∼3.1 LAEs of
Ciardullo et al. (2012, Cat. J/ApJ/744/110), all in the ECDF-S. The
V606-band cutouts and morphological properties of the Gronwall et al.
(2007, Cat. J/ApJ/667/79) sample are already published in Bond et al.
(2009, Cat. J/ApJ/705/639). In this study, we use F606W imaging from
the Galaxy Evolution from Morphology and SEDs survey (GEMS; Rix et al.
2004ApJS..152..163R 2004ApJS..152..163R), Great Observatories Origins Deep Survey (GOODS;
Giavalisco et al. 2004, Cat. II/261), and Hubble Ultradeep Field
Survey (HUDF; Beckwith et al. 2006, Cat. J/AJ/132/1729). These surveys
cover 800, 160, and 11arcmin2 of sky, respectively, and reach
average 5σ detection limits of mAB=28.3, 28.8, and 30.5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 57 120 z=2.1 LAE properties
table3.dat 57 59 z=3.1 LAE properties
table4.dat 76 105 *z=2.1 LAE component properties
table5.dat 76 58 *z=3.1 LAE component properties
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Note on table4.dat and table5.dat: a photometric "component" is any contiguous
source within rsel (rsel=0.65" at z=2.1 and 0.6" at z=3.1) of the
ground-based Lyα centroid of an LAE, where sources are identified
in the V606 HST images using SExtractor (sections 3.1 and 4.3).
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See also:
II/261 : GOODS initial results (Giavalisco+, 2004)
J/ApJ/751/29 : Lyα profiles of LAEs at z=3.1 (Yamada+, 2012)
J/ApJ/744/110 : LAE galaxies between 2.1=<z≤3.1 (Ciardullo+, 2012)
J/ApJ/743/9 : z=3.1 LAEs morphological properties (Gronwall+, 2011)
J/ApJ/736/31 : HETDEX pilot survey. II. 1.9<z<3.8 LAEs (Blanc+, 2011)
J/ApJ/705/639 : Sizes of Lyman alpha emitters at z=3.1 (Bond+, 2009)
J/ApJ/667/79 : Lyα emission-line galaxies at z=3.1 (Gronwall+, 2007)
J/A+A/461/823 : Candidate Lyα emitting galaxies (Venemans+, 2007)
J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- ID Source identification (G1)
6- 10 A5 --- Survey Survey identification (GEMS, GOODS or HUDF)
12 I1 h RAh [3] Hour of right ascension (J2000) (1)
14- 15 I2 min RAm [31/33] Minute of right ascension (J2000)
17- 22 F6.3 s RAs Second of right ascension (J2000)
24 A1 --- DE- [-] Sign of declination (J2000) (1)
25- 26 I2 deg DEd [27/28] Degree of declination (J2000) (1)
28- 29 I2 arcmin DEm Arcminute of declination (J2000)
31- 36 F6.3 arcsec DEs Arcsecond of declination (J2000)
38- 42 F5.2 mag Vmag [24/30.1]? HST V-band AB magnitude
44- 47 F4.2 mag e_Vmag [0.02/5.3]? Vmag uncertainty
49- 52 F4.2 arcsec Sep [0.01/0.7]? Distance between ACS and
ground-based centroids
54- 57 F4.2 arcsec Re [0.02/0.5]? Half-light radius computed
by PHOT (2)
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Note (1): Position of ACS centroid (set to ground-based position when there are
no SExtractor detections).
Note (2): Half-light radius computed by PHOT (not reported for LAEs without
SExtractor detections).
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Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID Source identification (G1)
6 I1 --- m_ID [1/4] Component number
8- 12 A5 --- Survey Survey identification (GEMS, GOODS or HUDF)
14 I1 h RAh [3] Hour of right ascension (J2000)
16- 17 I2 min RAm [31/33] Minute of right ascension (J2000)
19- 24 F6.3 s RAs Second of right ascension (J2000)
26 A1 --- DE- [-] Sign of declination (J2000)
27- 28 I2 deg DEd [27/28] Degree of declination (J2000)
30- 31 I2 arcmin DEm Arcminute of declination (J2000)
33- 38 F6.3 arcsec DEs Arcsecond of declination (J2000)
40- 44 F5.2 mag Vmag [24.5/29.5] HST V-band AB magnitude
(SExtractor)
46- 49 F4.2 mag e_Vmag [0.01/0.3] Vmag uncertainty
51- 54 F4.2 arcsec Sep [0.01/0.6] Distance from ground-based
Lyα position
56- 59 F4.2 --- b/a [0.2/1] Isophotal axis ratio computed by
SExtractor
61- 66 F6.2 deg theta [-90/88] Isophotal position angle computed
by SExtractor
68- 71 F4.2 arcsec Re [0.05/0.3] Half-light radius computed by
SExtractor
73- 76 F4.2 Msun/yr SFR [0.05/5.3] UV star formation rate
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Global notes:
Note (G1): Numbers in table2 are from Guaita et al. (2010ApJ...714..255G 2010ApJ...714..255G).
Identifiers in table3 (CNNN) are from table 2 of Ciardullo et al. 2012,
Cat. J/ApJ/744/110.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 14-Feb-2014