J/ApJ/599/1006 DEEP Groth Strip Survey. VII. (Kobulnicky+, 2003)
The DEEP Groth Strip Survey.
VII. The metallicity of field galaxies at 0.26<z<0.82 and
the evolution of the luminosity-metallicity relation.
Kobulnicky H.A., Willmer C.N.A., Phillips A.C., Koo D.C., Faber S.M.,
Weiner B.J., Sarajedini V.L., Simard L., Vogt N.P.
<Astrophys. J., 599, 1006-1030 (2003); Erratum Vol. 610, p. 1234 (2004)>
=2003ApJ...599.1006K 2003ApJ...599.1006K
ADC_Keywords: Galaxies, photometry ; Redshifts ; Abundances ; H II regions
Keywords: galaxies: abundances - galaxies: evolution -
galaxies: fundamental parameters - galaxies: starburst -
H II regions - ISM: abundances
Abstract:
Using spectroscopic data from the Deep Extragalactic Evolutionary
Probe Groth Strip Survey (DGSS), we analyze the gas-phase oxygen
abundances in the warm ionized medium for 64 emission-line field
galaxies in the redshift range 0.26<z<0.82. These galaxies
comprise a small subset selected from among 693 objects in the DGSS.
They are chosen for chemical analysis by virtue of having the
strongest emission lines. Oxygen abundances relative to hydrogen are
in the range 8.4<12+log(O/H)<9.0 with typical internal plus
systematic measurement uncertainties of 0.17dex. The 64 DGSS galaxies
collectively exhibit an increase in metallicity with B-band
luminosity, i.e., an L-Z relation like that seen among local galaxies.
Using the DGSS sample and local galaxy samples for comparison, we
searched for a "second parameter" that might explain some of the
dispersion seen in the L-Z relation. Parameters such as galaxy color,
emission-line equivalent width, and effective radius were explored but
found to be uncorrelated with residuals from the mean L-Z relation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 142 66 DGSS Selected Galaxies
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See also:
J/ApJS/142/1 : DEEP Groth Strip Survey. II (Simard+, 2002)
J/ApJS/157/175 : DEEP Groth Strip Survey. VIII (Koo+, 2005)
J/ApJ/571/136 : DEEP Groth Strip survey. X (Im+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Reference ID number for this paper
4- 11 A8 --- GID Groth Strip survey ID
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 24 F6.3 s RAs Second of Right Ascension (J2000)
25 A1 --- DE- Sign of Declination (J2000)
26- 27 I2 deg DEd Degree of Declination (J2000)
29- 30 I2 arcmin DEm Arcminute of Declination (J2000)
32- 36 F5.2 arcsec DEs Arcsecond of Declination (J2000)
38- 43 F6.4 --- z Redshift from optical emission lines
45- 49 F5.2 mag Imag The I814 band AB magnitude
51- 55 F5.1 mag BMAG Absolute rest-frame B band magnitude (1)
57- 60 F4.2 mag B-V Rest-frame (B-V) color index
62- 65 F4.2 kpc R-hl I814 image half light radius
67- 70 F4.2 --- B/T I814 image bulge fraction
72- 75 F4.2 --- RT RT asymmetry index (7)
77- 80 F4.2 --- RA RA asymmetry index (7)
82- 86 F5.1 0.1nm EW3727 The [O II] (3727Å) equivalent width (2)
88- 91 F4.1 0.1nm e_EW3727 Uncertainty in EW3727
93- 97 F5.1 0.1nm EW4861 The Hβ equivalent width (3)
99-101 F3.1 0.1nm e_EW4861 Uncertainty in EW4861
103-107 F5.1 0.1nm EW4959 The [O III] (4959Å) equivalent width (2)
109-112 F4.1 0.1nm e_EW4959 Uncertainty in EW4959
114-118 F5.1 0.1nm EW5007 The [O III] (5007Å) equivalent width (2)
120-123 F4.1 0.1nm e_EW5007 Uncertainty in EW5007
125-128 F4.2 [---] 12+logO/H Oxygen abundance, 12+log(O/H) (4)
130-133 F4.2 [---] e_12+logO/H The 1σ error in O/H (4)
135-138 F4.1 solMass/yr SFR Estimated star formation rate (5)
140-142 A3 --- Note Additional notes (6)
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Note (1): For H0=70km/s/Mpc, ΩM=0.3, ΩΛ=0.7.
Note (2): Corrected to the rest frame (divided by (1+z))
Note (3): Corrected to the rest frame (no correction for stellar absorption).
Note (4): From the empirical R23 method
following McGaugh, 1991ApJ...380..140M 1991ApJ...380..140M as formulated in Kobulnicky
et al. (1999ApJ...514..544K 1999ApJ...514..544K) after correction for 2Å of stellar
absorption in the EW4861. An additional uncertainty of 20% has been
added to the EW_[O II]_ as discussed in the text. An additional
uncertainty of ∼0.15dex in O/H representing uncertainties in the
photoionization models and empirical strong-line calibration should
be added in quadrature to the tabulated measurement errors.
Note (5): Based on Hβ flux (not corrected for stellar absorption),
derived from the EW4861 and V-band absolute magnitude. We estimate the
Hβ luminosity as LHβ(erg/s)=5.49E31*2.5-MV_^*EW4861. The
SFR then is computed by SFR(solMass/yr)=2.8*LHβ/1.12E41 which
assumes the Kennicutt (1983ApJ...272...54K 1983ApJ...272...54K) calibration of SFR in
terms of Hα luminosity. This estimate is a lower limit since
extinction and stellar Balmer absorption are not taken into account.
Note (6): Additional notes as follows:
A = Probable star-forming galaxy (non-AGN or minimal AGN
contribution), as defined in text.
B = [O II] EW is particularly uncertain due to low continuum levels.
C = Low-luminosity object with line ratios in the "turn-around"
region of the strong-line abundance diagram, so the oxygen
abundance is highly uncertain, in the range 7.8<12+log(O/H)<8.4.
Object removed from remaining analysis.
D = Object is a probable AGN on basis of [NeIII]/[OII]>0.4.
Note (7): Asymmetry indices as defined in paper II:
The asymmetry parameter RA + RT was found to be a good estimate
of the total asymmetric flux present in large, bright galaxies.
RT = (RT)raw - (RT)bkg
= [{Sum}i,j(1/2)|Rij+Rij180|-{Sum}i,j(1/2)|Bij+Bij180|]/[∑i,jIij]
RA = (RA)raw - (RA)bkg
= [{Sum}i,j(1/2)|Rij-Rij180|-{Sum}i,j(1/2)|Bij-Bij180|]/[∑i,jIij]
where the Rij are pixel values in the residual image, and the
Rij180 are pixel values in the residual image rotated by 180°
Bij are background pixel values in the residual image, and the
Bij180 are background pixel values in the residual image rotated
by 180°. Iij is the image.
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History:
From electronic version of the journal
References:
Vogt et al., Paper I 2005ApJS..159...41V 2005ApJS..159...41V
Simard et al., Paper II 2002ApJS..142....1S 2002ApJS..142....1S, Cat. J/ApJS/142/1
Weiner et al., Paper III 2005ApJ...620..595W 2005ApJ...620..595W
Koo et al., Paper VIII 2005ApJS..157..175K 2005ApJS..157..175K, Cat. J/ApJS/157/175
Gebhardt et al., Paper IX 2003ApJ...597..239G 2003ApJ...597..239G
Im et al. Paper X 2002ApJ...571..136I 2002ApJ...571..136I, Cat. J/ApJ/571/136
Kobulnicky et al., Paper XII 2002AAS...201.5218K 2002AAS...201.5218K
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 20-Feb-2004