Boyett, KNK;
Stark, DP;
Bunker, AJ;
Tang, M;
Maseda, MV;
(2022)
The [OIII]λ5007 equivalent width distribution at z ∼2: The redshift evolution of the extreme emission line galaxies.
Monthly Notices of the Royal Astronomical Society
, 513
(3)
pp. 4451-4463.
10.1093/mnras/stac1109.
Preview |
Text
stac1109 (1).pdf Download (1MB) | Preview |
Abstract
We determine the [OIII]$\lambda5007$ equivalent width (EW) distribution of $1.700<\rm{z}<2.274$ rest-frame UV-selected (M$_{\rm{UV}}<-19$) star-forming galaxies in the GOODS North and South fields. We make use of deep HDUV broadband photometry catalogues for selection and 3D-HST WFC3/IR grism spectra for measurement of line properties. The [OIII]$\lambda5007$ EW distribution allows us to measure the abundance of extreme emission line galaxies (EELGs) within this population. We model a log-normal distribution to the [OIII]$\lambda5007$ rest-frame equivalent widths of galaxies in our sample, with location parameter $\mu=4.24\pm0.07$ and variance parameter $\sigma= 1.33\pm0.06$. This EW distribution has a mean [OIII]$\lambda5007$ EW of 168$\pm1\r{A}$. The fractions of $\rm{z}\sim2$ rest-UV-selected galaxies with [OIII]$\lambda5007$ EWs greater than $500, 750$ and $1000\r{A}$ are measured to be $6.8^{+1.0}_{-0.9}\%$, $3.6^{+0.7}_{-0.6}\%$, and $2.2^{+0.5}_{-0.4}\%$ respectively. The EELG fractions do not vary strongly with UV luminosity in the range ($-21.6<M_{\rm{UV}}<-19.0$) considered in this paper, consistent with findings at higher redshifts. We compare our results to $\rm{z}\sim5$ and $\rm{z}\sim7$ studies where candidate EELGs have been discovered through Spitzer/IRAC colours, and we identify rapid evolution with redshift in the fraction of star-forming galaxies observed in an extreme emission line phase (a rise by a factor $\sim10$ between $\rm{z}\sim2$ and $\rm{z}\sim7$). This evolution is consistent with an increased incidence of strong bursts in the galaxy population of the reionisation era. While this population makes a sub-dominant contribution of the ionising emissivity at $\rm{z}\simeq2$, EELGs are likely to dominate the ionising output in the reionisation era.
Type: | Article |
---|---|
Title: | The [OIII]λ5007 equivalent width distribution at z ∼2: The redshift evolution of the extreme emission line galaxies |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1093/mnras/stac1109 |
Publisher version: | http://dx.doi.org/10.1093/mnras/stac1109 |
Language: | English |
Additional information: | This is the published version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
Keywords: | galaxies: evolution, high-redshift |
UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10148227 |
Archive Staff Only
![]() |
View Item |