The [O III]?5007 equivalent width distribution at z ? 2: the redshift evolution of the extreme emission line galaxies

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 GOODS North and South fields. make use deep HDUV broadband photometry catalogues for selection 3D-HST WFC3/IR grism spectra measurement line properties. The EW allows us to measure abundance extreme emission (EELGs) within this population. model a log-normal widths our sample, with location parameter $\mu=4.24\pm0.07$ variance $\sigma= 1.33\pm0.06$. This has mean 168$\pm1\r{A}$. fractions $\rm{z}\sim2$ rest-UV-selected EWs greater than $500, 750$ $1000\r{A}$ are measured be $6.8^{+1.0}_{-0.9}\%$, $3.6^{+0.7}_{-0.6}\%$, $2.2^{+0.5}_{-0.4}\%$ respectively. EELG do not vary strongly UV luminosity range ($-21.6<M_{\rm{UV}}<-19.0$) considered paper, consistent findings at higher redshifts. compare results $\rm{z}\sim5$ $\rm{z}\sim7$ studies where candidate EELGs have been discovered through Spitzer/IRAC colours, we identify rapid evolution redshift fraction observed an phase (a rise by factor $\sim10$ between $\rm{z}\sim7$). is increased incidence strong bursts galaxy population reionisation era. While makes sub-dominant contribution ionising emissivity $\rm{z}\simeq2$, likely dominate output