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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The 8 o'clock arc is a gravitationally lensed Lyman Break Galaxy (LBG) atredshift z=2.73 that has a star-formation rate (SFR) of 270 solar-mass/year(derived from optical and near-infrared spectroscopy). Taking the magnificationof the system ~12 and the SFR into account, the expected flux density of anyassociated radio emission at 1.4 GHz is predicted to be just 0.1 mJy. However,the lens system is found to be coincident with a radio source detected in theNRAO Very Large Array (VLA) Sky Survey with a flux density of ~5 mJy. If thisflux density is attributed to the lensed LBG then it would imply a SFR ~11000solar-mass/year, in contrast with the optical and near-infrared derived value.We want to investigate the radio properties of this system, and independentlydetermine the SFR for the LBG from its lensed radio emission. We have carriedout new high resolution imaging with the VLA ain A and B-configurations at 1.4and 5 GHz. We find that the radio emission is dominated by a radio-loud AGNassociated with the lensing galaxy. The radio-jet from the AGN partially coversthe lensed arc of the LBG, and we do not detect any radio emission from theunobscured region of the arc down to a 3 sigma flux-density limit of 108micro-Jy/beam. Using the radio data, we place a limit of <750 solar-mass/yearfor the SFR of the LBG, which is consistent with the results from the opticaland near-infrared spectroscopy. We expect that the sensitivity of the ExpandedVLA will be sufficient to detect many high redshift LBGs that aregravitationally lensed after only a few hours of observing time. The highangular resolution provided by the EVLA will also allow detailed studies of thelensed galaxies and determine if there is radio emission from the lens.

Very Large Array observations of the 8 o'clock arc lens system: Radio emission and a limit on the star-formation rate