J/ApJ/827/74 [NII]/Hα ratio in galaxies with KMOS3D (Wuyts+, 2016)
The evolution of metallicity and metallicity gradients from z=2.7 to 0.6
with KMOS-3D.
Wuyts E., Wisnioski E., Fossati M., Forster Schreiber N.M., Genzel R.,
Davies R., Mendel J.T., Naab T., Rottgers B., Wilman D.J., Wuyts S.,
Bandara K., Beifiori A., Belli S., Bender R., Brammer G.B., Burkert A.,
Chan J., Galametz A., Kulkarni S.K., Lang P., Lutz D., Momcheva I.G.,
Nelson E.J., Rosario D., Saglia R.P., Seitz S., Tacconi L.J., Tadaki K.-I.,
Ubler H., van Dokkum P.
<Astrophys. J., 827, 74-74 (2016)>
=2016ApJ...827...74W 2016ApJ...827...74W (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Abundances ; Redshifts
Keywords: galaxies: abundances; galaxies: evolution; galaxies: high-redshift
Abstract:
We present measurements of the [NII]/Hα ratio as a probe of
gas-phase oxygen abundance for a sample of 419 star-forming galaxies
at z=0.6-2.7 from the KMOS3D near-IR multi-integral field unit (IFU)
survey. The mass-metallicity relation (MZR) is determined consistently
with the same sample selection, metallicity tracer, and methodology
over the wide redshift range probed by the survey. We find good
agreement with long-slit surveys in the literature, except for the
low-mass slope of the relation at z∼2.3, where this sample is less
biased than previous samples based on optical spectroscopic redshifts.
In this regime we measure a steeper slope than some literature
results. Excluding the contribution from active galactic nuclei from
the MZR reduces sensitivity at the high-mass end, but produces
otherwise consistent results. There is no significant dependence of
the [NII]/Hα ratio on star formation rate at fixed redshift and
stellar mass. The IFU data allow spatially resolved measurements of
[NII]/Hα, from which we can infer abundance gradients for 180
galaxies, thus tripling the current sample in the literature. The
observed gradients are on average flat, with only 15 gradients
statistically offset from zero at >3σ. We have modeled the
effect of beam smearing, assuming a smooth intrinsic radial gradient
and known seeing, inclination, and effective radius for each galaxy.
Our seeing-limited observations can recover up to 70% of the intrinsic
gradient for the largest, face-on disks, but only 30% for the smaller,
more inclined galaxies. We do not find significant trends between
observed or corrected gradients and any stellar population, dynamical,
or structural galaxy parameters, mostly in agreement with existing
studies with much smaller sample sizes. In cosmological simulations,
strong feedback is generally required to produce flat gradients at
high redshift.
Description:
The galaxies analyzed here are taken from the first 2yr of the
KMOS3D survey, which covers observations up to 2015 April. The
survey is described in detail by Wisnioski+ (2015ApJ...799..209W 2015ApJ...799..209W).
KMOS3D is a 5yr GTO survey with the multi-object near-IR integral
field spectrograph KMOS at the Very Large Telescope (VLT).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 55 259 Target properties for all galaxies where
the [NII]/Hα ratio could be measured
--------------------------------------------------------------------------------
See also:
J/A+A/594/A77 : KMOS star-forming gal. Halpha data cubes (Di Teodoro+, 2016)
J/ApJ/822/42 : z∼3.3 star-forming galaxies NIR spectra (Onodera+, 2016)
J/ApJ/817/10 : Star-forming z∼2.1 galaxy metallicities (Grasshorn Gebhardt+,
2016)
J/ApJS/220/12 : FMOS-COSMOS survey III. 0.7<z<2.5 galaxies (Silverman+, 2015)
J/AJ/148/137 : Merging galaxies in COSMOS to z∼1 (Lackner+, 2014)
J/ApJS/214/24 : 3D-HST+CANDELS catalog (Skelton+, 2014)
J/ApJ/768/74 : PHIBSS: CO obs. of star-forming galaxies (Tacconi+, 2013)
J/ApJ/765/140 : Stacked spectra of SDSS star forming gal. (Andrews+, 2013)
J/ApJS/203/24 : Structural param. of galaxies in CANDELS (van der Wel+, 2012)
J/A+A/532/A90 : PACS Evolutionary Probe (PEP-DR1) catalogs (Lutz+, 2011)
J/ApJ/706/1364 : SINS survey of high-redshift gal. (Forster Schreiber+, 2009)
J/MNRAS/358/521 : Grid of chemical evolution models for galaxies (Molla+, 2005)
J/AJ/116/2805 : H II regions in spiral galaxies (Van Zee+, 1998)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/259] Running sequence number
5- 9 F5.3 --- z [0.7/2.6] Redshift
11- 15 F5.2 [Msun] logM* [8.5/11.4] Stellar mass
17- 20 F4.1 kpc re [0.5/16]? Effective radius re
22- 26 F5.1 Msun/yr SFR [0.2/397.8] Hα star formation rate (1)
28 A1 --- l_[NII]/Ha Limit flag on [NII]/Ha
30- 33 F4.2 --- [NII]/Ha [0.08/1.4] Integrated [NII]/Hα ratio
35- 38 F4.2 --- e_[NII]/Ha [0/0.3]? [NII]/Ha uncertainty
40- 45 F6.3 --- dN2/dr [-0.2/0.2]? ΔN2/Δr value,
in units of dex/kpc (2)
47- 51 F5.3 --- e_dN2/dr [0.002/0.08]? dN2/dr uncertainty
53- 55 F3.1 --- BCF [1.3/6.2]? Multiplicative beam-smearing
correction factor for the N2 gradient (3)
--------------------------------------------------------------------------------
Note (1): Hα-based SFR corrected for dust extinction using the SED-derived
reddening and accounting for additional extinction of the nebular
lines following Wuyts et al. (2013ApJ...779..135W 2013ApJ...779..135W).
Note (2): Observed gradient in [NII]/Hα, excluding the nuclear region for
AGN-flagged targets. Reported only when measurable.
Note (3): Multiplicative beam-smearing correction factor for the N2 gradient,
derived from simple analytical models assuming a smooth linear
intrinsic radial gradient.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 24-Nov-2016