HeII emitters in the VIMOS VLT Deep Survey: PopIII star formation or peculiar stellar populations in galaxies at 2<z<4.6?

Understand

The aim of this work is to identify HeII emitters at 2<z<4.6 and to constrain the source of the hard ionizing continuum that powers the HeII emission.

• We have assembled a sample of 277 galaxies with a high quality spectroscopic redshift at 2<z<4.6 from the VVDS survey, and we have identified 39 HeII1640A emitters.
• We study their spectral properties, measuring the fluxes, equivalent widths (EW) and FWHM for most relevant lines.
• About 10% of galaxies at z~3 show HeII in emission, with rest frame equivalent widths EW0~1-7A, equally distributed between galaxies with Lya in emission or in absorption.