Date: 10/24/2024
Arxiv: Extreme emission line galaxies detected in JADES JWST/NIRSpec I:
inferred galaxy properties
Published: 1/30/2024 1:57:04 PM
Updated: 10/23/2024 7:38:06 PM
Paper abstract: Extreme emission line galaxies (EELGs) exhibit large equivalent widths (EW)in their rest-optical emission lines ([OIII]\lambda5007 or H\alpharest-frame EW > 750\r{A}) which can be tied to a recent upturn in starformation rate, due to the sensitivity of the nebular line emission and therest-optical continuum to young (<10Myr) and evolved stellar populations,respectively. By studying a sample of 85 star forming galaxies (SFGs), spanningthe redshift and magnitude interval 3 M_{UV}>-21, in theJWST Advanced Deep Extragalactic Survey (JADES) with NIRSpec/prismspectroscopy, we determine that SFGs initiate an EELG phase when entering asignificant burst of star formation, with the highest EWs observed in EELGswith the youngest luminosity-weighted ages (<5 Myr old) and the highest burstintensity (those with the greatest excess between their current and long-termaverage SFR). We spectroscopically confirm that a greater proportion of SFGsare in an EELG phase at high redshift in our UV-selected sample (61\pm4\% inour z>5.7 high-redshift bin, compared to 23^{+4}_{-1}\% in ourlowest-redshift bin 35.7 have observed Lyman-\alpha emission, potentially lying within largeionised regions. The high detection rate of Lyman-\alpha emitters in our EELGselection suggests that the physical conditions associated with entering anEELG phase also promote the escape of Lyman-\alpha photons.
