English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The Lyman-$\alpha$ (Ly$\alpha$) emission line has been ubiquitously used toconfirm and study high redshift galaxies. We report on the line morphology asseen in the 2D spectra from the VIMOS Ultra Deep Survey in a sample of 914Ly$\alpha$ emitters from a parent sample of 4192 star-forming galaxies at$2<z_\mathrm{spec}\lesssim6$. The study of the spatial extent of Ly$\alpha$emission provides insight into the escape of Ly$\alpha$ photons from galaxies.We classify the line emission as either non-existent, coincident, projectedspatial offset, or extended with respect to the observed 2D UV continuumemission. The line emitters in our sample are classified as ~45% coincident,~24% extended and ~11% offset emitters. For galaxies with detected UVcontinuum, we show that extended Ly$\alpha$ emitters (LAEs) correspond to thehighest equivalent width galaxies (with an average$W_\mathrm{Ly\alpha}\sim-22${\AA}). This means that this class of objects isthe most common in narrow-band selected samples, which usually select highequivalent width LAEs, $<-20${\AA}. Extended Ly$\alpha$ emitters are found tobe less massive, less star-forming, with lower dust content, and smaller UVcontinuum sizes ($r_{50}\sim0.9$kpc) of all the classes considered here. Wealso find that galaxies with larger UV-sizes have lower fractions of Ly$\alpha$emitters. By stacking the spectra per emitter class we find that the weakerLy$\alpha$ emitters have stronger low ionization inter-stellar medium (ISM)absorption lines. Interestingly, we find that galaxies with Ly$\alpha$ offsetemission (median separation of $1.1_{-0.8}^{+1.3}$kpc from UV continuum) showsimilar velocity offsets in the ISM as those with no visible emission (anddifferent from other Ly$\alpha$ emitting classes). This class of objects mayhint at episodes of gas accretion, bright offset clumps, or on-going mergingactivity into the larger galaxies.

The VIMOS Ultra-Deep Survey: the Ly$\alpha$ emission line morphology at $2 < z < 6$