J/ApJ/817/10 Star-forming z∼2.1 galaxy metallicities (Grasshorn Gebhardt+, 2016)
Young, star-forming galaxies and their local counterparts: the evolving
relationship of mass-SFR-metallicity since z ∼ 2.1.
Grasshorn Gebhardt H.S., Zeimann G.R., Ciardullo R., Gronwall C., Hagen A.,
Bridge J.S., Schneider D.P., Trump J.R.
<Astrophys. J., 817, 10 (2016)>
=2016ApJ...817...10G 2016ApJ...817...10G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Photometry, HST ; Spectroscopy
Keywords: cosmology: observations; galaxies: evolution; galaxies: formation;
galaxies: high-redshift
Abstract:
We explore the evolution of the Stellar Mass-Star Formation Rate
(SFR)-Metallicity relation using a set of 256 COSMOS and GOODS
galaxies in the redshift range 1.90<z<2.35. We present the galaxies'
rest-frame optical emission-line fluxes derived from IR-grism
spectroscopy with the Hubble Space Telescope and combine these data
with SFRs and stellar masses obtained from deep, multi-wavelength
(rest-frame UV to IR) photometry. We then compare these measurements
to those for a local sample of galaxies carefully matched in stellar
mass (7.5≲log(M*/M☉≲10.5) and SFR (-0.5≲log(SFR)≲2.5
in M☉/yr). We find that the distribution of z∼2.1 galaxies in
stellar mass-SFR-metallicity space is clearly different from that
derived for our sample of similarly bright (LHβ>3x1040erg/s)
local galaxies, and this offset cannot be explained by simple
systematic offsets in the derived quantities. At stellar masses above
∼109M☉ and SFRs above ∼10M☉/yr, the z∼2.1 galaxies have
higher oxygen abundances than their local counterparts, while the
opposite is true for lower-mass, lower-SFR systems.
Description:
To select our sample of z∼2.1 galaxies, we began with the G141 near-IR
grism data from the HST's Wide Field Camera 3 (WFC3; GO programs
11600, 12177, and 12328). This data set, which is the product of the
3D-HST (Brammer et al. 2012ApJS..200...13B 2012ApJS..200...13B) and AGHAST (Weiner &
AGHAST Team 2014AAS...22322707W 2014AAS...22322707W) surveys, extends over 625arcmin2
and covers five well-studied fields, including our targeted regions of
COSMOS, GOODS-N, and GOODS-S.
In these regions, there exist deep optical and IR images from the HST
CANDELS program (Grogin et al. 2011ApJS..197...35G 2011ApJS..197...35G; Koekemoer et al.
2011ApJS..197...36K 2011ApJS..197...36K), near-IR grism spectra from HST (Brammer et al.
2012ApJS..200...13B 2012ApJS..200...13B) providing OII, NeIII, Halpha and Hbeta fluxes,
and supplemental broad- and intermediate-bandpass photometry from a
host of ground-based studies (Skelton et al. 2014, J/ApJS/214/24). By
combining these data, we can measure the metallicities, stellar
masses, and SFRs
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 90 256 3D-HST line fluxes
table2.dat 85 256 3D-HST derived properties
--------------------------------------------------------------------------------
See also:
II/261 : GOODS initial results (Giavalisco+, 2004)
J/AJ/149/79 : Spectro of galaxies from NewHa survey (de los Reyes+, 2015)
J/ApJS/220/12 : FMOS-COSMOS survey III. 0.7<z<2.5 galaxies (Silverman+, 2015)
J/ApJS/214/24 : 3D-HST+CANDELS catalog (Skelton+, 2014)
J/MNRAS/428/1128 : UDS/COSMOS HiZELS galaxies (Sobral+, 2013)
J/ApJ/777/18 : Stellar mass functions of galaxies to z=4 (Muzzin+, 2013)
J/ApJ/765/140 : SDSS star forming galaxies stacked spectra (Andrews+, 2013)
J/A+A/545/A141 : UV selected sources in the GOODS-S field (Buat+, 2012)
J/A+A/533/A119 : GOODS-Herschel North and South catalogs (Elbaz+, 2011)
J/MNRAS/413/971 : Galaxy And Mass Assembly (GAMA) DR1 (Driver+, 2011)
J/ApJ/706/1364 : High-redshift galaxies SINS survey (Forster Schreiber+, 2009)
J/A+A/459/85 : O/H and gas densities in star-forming galaxies (Nagao+, 2006)
J/ApJ/647/128 : Hα observations of UV-selected galaxies (Erb, 2006)
J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006)
http://wwwmpa.mpa-garching.mpg.de/SDSS/DR7/ : MPA-JHU DR7 release home page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/256] Running index number
5- 6 I2 h RAh Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 15 F5.2 s RAs Second of Right Ascension (J2000)
17 A1 --- DE- Sign of the Declination (J2000)
18- 19 I2 deg DEd Degree of Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Declination (J2000)
24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000)
29- 33 F5.2 mag F140W [21.7/25.9] HST/WFC3 F140W band magnitude
35- 38 F4.2 --- z [1.9/2.4] Redshift
40- 44 F5.2 10-19W/m2/nm OII [0.5/16]? The [OII](3727Å) flux
density (1)
46- 49 F4.2 10-19W/m2/nm e_OII [0.4/6]? Uncertainty in OII (1)
51- 54 F4.2 10-19W/m2/nm NeIII [0.4/6]? The [NeIII](3869Å) flux
density (1)
56- 59 F4.2 10-19W/m2/nm e_NeIII [0.3/3]? Uncertainty in NeIII (1)
61- 64 F4.2 10-19W/m2/nm Hg [0.4/3.4]? The Hγ flux density (1)
66- 69 F4.2 10-19W/m2/nm e_Hg [0.4/2]? Uncertainty in Hg (1)
71- 74 F4.2 10-19W/m2/nm Hb [0.3/9]? The Hβ flux density (1)(2)
76- 79 F4.2 10-19W/m2/nm e_Hb [0.2/3]? Uncertainty in Hb (1)(2)
81- 85 F5.2 10-19W/m2/nm OIII [1/40] The [OIII](5007Å) flux density
87- 90 F4.2 10-19W/m2/nm e_OIII [0.3/4] Uncertainty in OIII
--------------------------------------------------------------------------------
Note (1): Flux densities are given in 10-17ergs/s/cm-2/Å. Blanks indicate
a signal-to-noise ratio less than 1.0.
Note (2): Includes the equivalent width correction from SED fitting.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/256] Running index number
5- 10 F6.3 Msun Mass [7/10.8] Stellar mass
12- 16 F5.3 Msun e_Mass [0.01/0.7] Uncertainty in Mass
18- 22 F5.2 [Msun/yr] logSFR [-0.7/3.5] Log Star Formation Rate
24- 27 F4.2 [Msun/yr] e_logSFR [0.01/2] Uncertainty in logSFR
29- 33 F5.2 --- beta [-3/1.6] UV slope index
35- 38 F4.2 --- e_beta [0.01/2.2] Uncertainty in beta
40- 44 F5.3 mag E(B-V) [0.003/1.9]? The (B-V) color index (3)
46- 50 F5.3 mag e_E(B-V) [0.006/1.1]? Uncertainty in E(B-V) (3)
52- 55 F4.2 [-] Z1 [7/9]? Most likely metallicity (4)
57- 60 F4.2 [-] Z2 [7.6/8.1]? Second likely possibility for
the metallicity (4)
62- 65 F4.2 [-] LoZA ? Lower bound of 1st error interval (5)
67- 70 F4.2 [-] HiZA ? Upper bound of 1st error interval (6)
72- 75 F4.2 [-] LoZB ? Lower bound of 2nd error interval (5)
77- 80 F4.2 [-] HiZB ? Upper bound of 2nd error interval (6)
82- 85 F4.2 [-] ZErr [0.1/1.6]? Total error on metallicity (7)
--------------------------------------------------------------------------------
Note (3): Blanks indicate where the UV slope gives a negative obscuration.
For these objects, we set E(B-V)=0mag.
Note (4): Here Metallicity means 12+log(O/H). The multiple values on the
metallicity come from the fact that the indicator R23 is
double-valued, and the other indicators are not always sufficient to
break that degeneracy. This is also the reason that the 1σ
error intervals are not always singly-connected, but instead split
into multiple intervals around the most likely values.
Note (5): Where a blank means that the lower bound is <7.0.
Note (6): Where a blank means that the upper bound is >9.0.
Note (7): Where ZErr=HiZB-LoZB+HiZA-LoZA.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Apr-2016