J/ApJ/617/240 Oxygen abundances in the GOODS-North field (Kobulnicky+, 2004)
Metallicities of 0.3<z<1.0 galaxies in the GOODS-North field.
Kobulnicky H.A., Kewley L.J.
<Astrophys. J., 617, 240-261 (2004)>
=2004ApJ...617..240K 2004ApJ...617..240K
ADC_Keywords: Abundances ; Equivalent widths ; Galaxies, photometry
Keywords: galaxies: abundances - galaxies: evolution -
galaxies: fundamental parameters - galaxies: starburst -
H II regions - ISM: abundances
Abstract:
We measure nebular oxygen abundances for 204 emission-line galaxies
with redshifts 0.3<z<1.0 in the Great Observatories Origins Deep
Survey-North (GOODS-N) field using spectra from the Team Keck Redshift
Survey, Cat. J/AJ/127/3121. We also provide an updated analytic
prescription for estimating oxygen abundances using the traditional
strong emission line ratio, R23, based on the photoionization models
of Kewley & Dopita (2002ApJS..142...35K 2002ApJS..142...35K). We include an analytic
formula for very crude metallicity estimates using the
[NII]λ6584/Hα ratio.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 170 204 GOOD-North TKRS selected galaxies
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See also:
J/ApJ/600/L93 : GOODS initial results (Giavalisco+, 2004)
J/AJ/127/3121 : TKRS survey of the GOODS-North field (Wirth+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- [KK2004b] Identification number
5- 9 I5 --- TKRS TKRS identifier (Wirth et al.,
Cat. J/AJ/127/3121)
11- 29 A19 --- GOODS GOODS-N v1.0 catalog identifier
31- 37 F7.5 --- z TKRS spectroscopic redshift
39- 43 F5.2 mag Rmag TKRS R-band magnitude (648.7±81nm,
AB system)
45- 49 F5.2 mag imag GOODS-N v1.0 i band F775W magnitude
51- 56 F6.2 mag BMAG Rest frame absolute B band magnitude (1)
58- 62 F5.3 mag U-B Rest frame (U-B) color index
64- 68 F5.1 0.1nm EWOII The [OII](3727) equivalent width (2)
70- 73 F4.1 0.1nm e_EWOII Uncertainty in EWOII
75- 78 F4.1 0.1nm EWHb The Hβ(4861) equivalent width (3)
80- 82 F3.1 0.1nm e_EWHb Uncertainty in EWHb
84- 88 F5.1 0.1nm EWOIII The [OIII](4959+5007) equivalent width (4)
90- 93 F4.1 0.1nm e_EWOIII Uncertainty in EWOIII
95 A1 --- l_EWHa/NII Limit flag on EWHa/NII
97-101 F5.2 0.1nm EWHa/NII ? Measured Hα/[NII](6584) equivalent
width ratio (2)
103-107 F5.2 solMass/yr SFR Estimated star formation rate (5)
109 I1 --- Code Code about oxygen abundance derivation (6)
111-115 F5.2 [-] log(O32) Log of the ratio of the oxygen lines (7)
117-121 F5.2 --- R23 Traditional strong emission line ratio (8)
123 A1 --- l_(O/H)M91 Limit flag on (O/H)M91
125-128 F4.2 [-] (O/H)M91 McGaugh (1991ApJ...380..140M 1991ApJ...380..140M) Oxygen
abundance, 12+log(O/H) (9)
130-133 F4.2 [-] e_(O/H)M91 ? The 1σ error in (O/H)M91
135 A1 --- l_(O/H)KD Limit flag on (O/H)KD
137-140 F4.2 [-] (O/H)KD Kewley & Dopita (2002ApJS..142...35K 2002ApJS..142...35K)
oxygen abundance, 12+log(O/H) (10)
142 A1 --- l_(O/H)avg Limit flag on (O/H)avg
144-147 F4.2 [-] (O/H)avg Mean (O/H)M91 and (O/H)KD abundance
149 A1 --- l_(O/H)NII Limit flag on (O/H)NII
151-154 F4.2 [-] (O/H)NII ? Oxygen abundance, 12+log(O/H), using
O32 and the [NII]/Hα ratio (11)
156 A1 --- l_O/H Limit flag on O/H
158-161 F4.2 [-] O/H Oxygen abundance, 12+log(O/H) (12)
163-166 F4.2 [-] e_O/H ? Error in O/H
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Note (1): H0=70km/s/Mpc, ΩM=0.3, ΩΛ=0.7.
Note (2): Corrected to the rest frame.
Note (3): Corrected to the rest frame but no correction for stellar absorption.
Note (4): Determined from 1.3*W_[O III]_(5007) and uncertainty,
corrected to the rest frame;
Note (5): Based on Hβ flux (not corrected for stellar absorption),
derived from the EWHb and BMag. We estimate the Hβ luminosity as
LHβ(erg/s)=5.49E31*2.5-BMag*EWHb. The SFR then is computed by
SFR(SolMass/yr)=2.8*LHβ/1.26E41 which assumes the Kennicutt
(1998ApJ...498..541K 1998ApJ...498..541K) calibration of SFR in terms of Hα
luminosity. This estimate is a lower limit since dust extinction and
stellar Balmer absorption are not taken into account.
Note (6): Code, defined as follows:
0 = oxygen abundance computed using
EWR23=(W[OII](3727)+1.3*W[OIII](5007))/WHβ;
1 = object is probably on the turnaround region of the R23-O/H calibration
or possibly on the lower branch based on the [NII](6584)/Hα ratio,
so lower branch formula of McGaugh (1991ApJ...380..140M 1991ApJ...380..140M) is applied and
averaged with the upper branch estimate of KD02 to arrive at the oxygen
abundance in (O/H)avg;
2 = oxygen abundance computed using
EWR23=(W[OII](3727)+4*W[OIII](4959))/WHβ;
3 = W[OIII](5007) is measured with signal-to-noise <3:1 so a 3σ
lower limit on the oxygen abundance is computed using
EWR23 = (W[OII](3727)+1.3*W[OIII](5007))/WHβ;
Note (7): log(O32)=1.3*W[OIII](5007)/W[OII](3727);
Note (8): R23=EWR23=(W[OIII](3727)+1.3*W[OII](5007))/WHβ
Note (9): From the empirical R23 method following McGaugh
(1991ApJ...380..140M 1991ApJ...380..140M) as formulated in KKP after correction for 2
Angstroms of stellar absorption in the EWHβ. The uncertainty
reflects statistical measurement error on the line EWs only, and does
not include systematic uncertainties in the calibration method which
may exceed 0.1dex in 12+log(O/H);
Note (10): Based on the EWR23 and the models of Kewley & Dopita
(2002ApJS..142...35K 2002ApJS..142...35K) as given in equations in the text;
Note (11): Estimated using O32 and the [NII]/Hα ratio in
conjunction with the photoionization models and parametric relations
of equation 12 and 13;
Note (12): This is simply the value from (O/H)avg in most cases.
For objects with code=1 that are on the lower branch or turnaround
region of the R23-O/H calibration, this value is the average of
(O/H)M91 and (O/H)KD. See text and Garnett, Kennicutt, & Bresolin
(2004ApJ...607L..21G 2004ApJ...607L..21G) for possible systematic uncertainties in the
absolute metallicities which may reach 0.2-0.5dex, particularly in
metal-rich systems.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 23-Jun-2005