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

Reionization-era galaxies tend to exhibit weak Ly$\alpha$ emission, likelyreflecting attenuation from an increasingly neutral IGM. Recent observationshave begun to reveal exceptions to this picture, with strong Ly$\alpha$emission now known in four of the most massive z=7$-$9 galaxies in the CANDELSfields, all of which also exhibit intense [OIII]$+$H$\beta$ emission (EW$>$800$\mathrm{\mathring{A}}$). To better understand why Ly$\alpha$ is anonymouslystrong in a subset of massive z$\simeq$7$-$9 galaxies, we have initiated anMMT/Binospec survey targeting a larger sample (N=22) of similarly luminous($\simeq$1$-$6 L$^{\ast}_{\mathrm{UV}}$) z$\simeq$7 galaxies selected over verywide-area fields ($\sim$3 deg$^2$). We confidently ($>$7$\sigma$) detectLy$\alpha$ in 78% (7/9) of galaxies with strong [OIII]$+$H$\beta$ emission(EW$>$800 $\mathrm{\mathring{A}}$) as opposed to only 8% (1/12) of galaxieswith more moderate (EW=200$-$800 $\mathrm{\mathring{A}}$) [OIII]$+$H$\beta$. Weargue that the higher Ly$\alpha$ EWs of the strong [OIII]$+$H$\beta$ populationlikely reflect enhanced ionizing photon production efficiency owing to theirlarge sSFRs ($\gtrsim$30 Gyr$^{-1}$). We also find evidence that Ly$\alpha$transmission from massive galaxies declines less rapidly over $6<z<7$ than inlow-mass lensed systems. In particular, our data suggest no strong evolution inLy$\alpha$ transmission, consistent with a picture wherein massive z$\simeq$7galaxies often reside in large ionized regions. We detect threeclosely-separated ($R$ = 1.7 physical Mpc) z$\simeq$7 Ly$\alpha$ emitters inour sample, conceivably tracing a large ionized structure that is consistentwith this picture. We detect tentative evidence for an overdensity in thisregion, implying a large ionizing photon budget in the surrounding volume.

MMT Spectroscopy of Lyman-alpha at z$\simeq$7: Evidence for Accelerated Reionization Around Massive Galaxies