Date: 1/31/2024
Arxiv: Extreme emission line galaxies detected in JADES JWST/NIRSpec I:
inferred galaxy properties
Published: 1/30/2024 1:57:04 PM
Updated: 1/30/2024 1:57:04 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 mass-weighted ages (<5 Myr old) and the highest burstintensity (those with the highest proportion of their total stellar mass formedin the last 10 Myr). We spectroscopically confirm that a greater proportion ofSFGs are in an EELG phase at high redshift in our UV-selected sample(61\pm4\% in our z>5.7 high-redshift bin, compared to 23^{+4}_{-1}\% inour lowest-redshift bin 35.7 have observed Lyman-\alpha emission, potentially lyingwithin large ionised regions. The high detection rate of Lyman-\alphaemitters in our EELG selection suggests that the physical conditions associatedwith entering an EELG phase also promote the escape of Lyman-\alpha photons.
