J/ApJ/743/9 z=3.1 LAEs morphological properties (Gronwall+, 2011)
The rest-frame ultraviolet light profile shapes of Lyα-emitting galaxies
at z = 3.1.
Gronwall C., Bond N.A., Ciardullo R., Gawiser E., Altmann M., Blanc G.A.,
Feldmeier J.J.
<Astrophys. J., 743, 9 (2011)>
=2011ApJ...743....9G 2011ApJ...743....9G
ADC_Keywords: Galaxies, photometry ; Morphology ; Redshifts
Keywords: cosmology: observations - galaxies: formation -
galaxies: high-redshift - galaxies: structure
Abstract:
We present a morphological analysis of the rest-frame ultraviolet
emission of 78 resolved, high signal-to-noise z∼3.1 Lyα emitters
(LAEs) in the Extended Chandra Deep Field-South. Using Hubble Space
Telescope/Advanced Camera for Surveys V-band images taken as part of
the Galaxy Evolution from Morphology and SEDs, Great Observatories
Origins Deep Survey, and Hubble Ultra Deep Field surveys, we
investigate both single-component and multi-component LAEs, and derive
concentration indices, Sersic indices, ellipticities, and half-light
radii for all resolved components and systems with a signal-to-noise
>30. We show that, although the LAE population is heterogeneous in
nature, most LAEs are highly concentrated, with a distribution of C
values similar to that measured for field stars; this suggests that
the diagnostic is a poor discriminator near the resolution limit. The
LAEs also display a wide range of Sersic indices (0<n<12), similar to
that seen for galaxies in the local neighborhood. However, the
majority of LAEs have n<2, and a visual inspection of the images
suggests that the small-n objects have extended or multimodal
luminosity profiles, while the LAEs with n>2 have compact components
surrounded by diffuse emission. Moreover, unlike nearby spiral
galaxies, whose distribution of ellipticities is flat, the LAE
ellipticity distribution peaks near 1-b/a∼0.55. Thus, the population
has more in common with z∼3 Lyman-break galaxies than local
star-forming objects.
Description:
Our study uses the statistically complete sample of z=3.1 LAEs
identified by Gronwall et al. (2007, Cat. J/ApJ/667/79) in their
narrowband 4990Å survey of the Extended Chandra Deep Field-South
(ECDF-S). As explained in Paper I (Bond et al. 2009,
Cat. J/ApJ/705/639), the sample contains 154 LAEs in a 0.32deg2 area
of sky, and 116 of the objects fall in fields observed by HST. To
summarize: the GEMS (Rix et al. 2004ApJS..152..163R 2004ApJS..152..163R) survey includes
97 LAEs and reaches a V-band 5σ point-source depth of 28.3mag,
the GOODS (Giavalisco et al. 2004, Cat. II/261) survey (Ver. 2.0)
contains 29 LAEs and goes to a point-source depth of V=28.8, and HUDF
(Beckwith et al. 2006, Cat. J/AJ/132/1729) contains 3 LAEs and reaches
a depth of V=30.2. In addition, the GEMS survey includes the first
epoch of GOODS observations which reach a depth of V=27.9.
We retrieved V606-band ACS images from the Multimission Archive at
the Space Telescope Science Institute (MAST).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 85 64 LAE component morphological properties
table2.dat 61 76 LAE system morphological properties
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
II/261 : GOODS initial results (Giavalisco+, 2004)
J/ApJ/736/31 : HETDEX pilot survey. II. 1.9<z<3.8 LAEs (Blanc+, 2011)
J/ApJ/705/639 : Paper I: Sizes of Lyman alpha emitters at z=3.1 (Bond+, 2009)
J/ApJ/673/143 : HST photometry of TN J1338-1942 (Overzier+, 2008)
J/ApJ/667/79 : Lyα emission-line galaxies at z=3.1 (Gronwall+, 2007)
J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)
J/A+A/431/793 : Ly-alpha emitters around MRC 0316-257 (Venemans+, 2005)
J/ApJ/631/85 : Galaxy morphologies in the Hubble UDF (Elmegreen+, 2005)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [GCH2007] [4/162] Object number (G1)
5 I1 --- m_[GCH2007] [1/4] Component number
7- 11 A5 --- Survey Survey name (HUDF, GOODS or GEMS)
13 I1 h RAh [3] Hour of right ascension (J2000)
15- 16 I2 min RAm [31/33] Minute of right ascension (J2000)
18- 23 F6.3 s RAs Second of right ascension (J2000)
25 A1 --- DE- [-] Sign of declination (J2000)
26- 27 I2 deg DEd [27/28] Degree of declination (J2000)
29- 30 I2 arcmin DEm Arcminute of declination (J2000)
32- 37 F6.3 arcsec DEs Arcsecond of declination (J2000)
39- 43 F5.2 mag VGF [25.0/27.7] SExtractor total magnitude VGF
45- 48 F4.2 mag e_VGF VGF uncertainty
50- 53 F4.2 kpc re [0.09/1.99] Half-light radius (re,GF)
55- 58 F4.2 kpc e_re re uncertainty
60- 64 F5.2 --- n [0.01/12.16] Sersic index
66- 70 F5.2 --- e_n n uncertainty
72- 75 F4.2 --- b/a Axis ratio
77- 80 F4.2 --- e_b/a b/a uncertainty
82- 85 F4.2 --- C [1.2/3.72]? Concentration index (G2)
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [GCH2007] [4/162] Object number (G1)
5- 9 A5 --- Survey Survey name (HUDF, GOODS or GEMS)
11 I1 h RAh [3] Hour of right ascension (J2000) (1)
13- 14 I2 min RAm [31/33] Minute of right ascension (J2000)
16- 21 F6.3 s RAs Second of right ascension (J2000)
23 A1 --- DE- [-] Sign of declination (J2000) (1)
24- 25 I2 deg DEd [27/28] Degree of declination (J2000) (1)
27- 28 I2 arcmin DEm Arcminute of declination (J2000)
30- 35 F6.3 arcsec DEs Arcsecond of declination (J2000)
37- 41 F5.2 mag Vph [24.8/27] V-band magnitude computed by PHOT
43- 46 F4.2 mag e_Vph Vph uncertainty
48- 51 F4.2 kpc reph [0.55/2.56] Half-light radius (2)
53- 56 F4.2 --- b/a Isophotal axis ratio about ACS centroid
58- 61 F4.2 --- C [1.97/3.78]? Concentration index (G2)
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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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Global note:
Note (G1): Index from Table 2 of Gronwall et al. (2007, Cat. J/ApJ/667/79;
<[GCH2007] NNN> in Simbad).
Note (G2): Following Conselice (2003, Cat. J/ApJS/147/1), we define this index
via C=5xlog(r80%/r20%), where r80% and r20% are the circular
radii containing 80% and 20% of the total flux. Table 1 lists these
values for each resolved LAE component, and Table 2 gives the
measurements for LAE systems. Missing entries in the table represent
extremely faint sources, for which we were unable to calculate a
value.
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History:
From electronic version of the journal
References:
Bond et al. Paper I. 2009ApJ...705..639B 2009ApJ...705..639B Cat. J/ApJ/705/639
(End) Emmanuelle Perret [CDS] 26-Apr-2013