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

We present the Ly$\alpha$ luminosity functions (LFs) at $z=$5.7 and 6.6derived from a new large sample of 1,266 Ly$\alpha$ emitters (LAEs) identifiedin total areas of 14 and 21 deg$^2$, respectively, based on the earlynarrowband data of the Subaru/Hyper Suprime-Cam (HSC) survey. Together withcareful Monte-Carlo simulations that account for the incompleteness of the LAEselection and the flux estimate systematics in the narrowband imaging, we havedetermined the Ly$\alpha$ LFs with the unprecedentedly small statistical andsystematic uncertainties in a wide Ly$\alpha$ luminosity range of$10^{42.8-43.8}$ erg s$^{-1}$. We obtain the best-fit Schechter parameters of$L^{*}_{{\rm Lya}}=1.6^{+2.2}_{-0.6} (1.7^{+0.3}_{-0.7}) \times10^{43}$ ergs$^{-1}$, $\phi^{*}_{{\rm Lya}}=0.85^{+1.87}_{-0.77}\(0.47^{+1.44}_{-0.44})\times10^{-4}$ Mpc$^{-3}$, and$\alpha=-2.6^{+0.6}_{-0.4}\ (-2.5^{+0.5}_{-0.5})$ at $z=5.7$ ($6.6$). Weconfirm that our best-estimate Ly$\alpha$ LFs are consistent with the majorityof the previous studies, but find that our Ly$\alpha$ LFs do not agree with thehigh number densities of LAEs recently claimed by Matthee/Santos et al.'sstudies that may overcorrect the incompleteness and the flux systematics. OurLy$\alpha$ LFs at $z=5.7$ and $6.6$ show an indication that the faint-end slopeis very steep ($\alpha \simeq -2.5$), although it is also possible that thebright-end LF results are enhanced by systematic effects such as thecontribution from AGNs, blended merging galaxies, and/or large ionized bubblesaround bright LAEs. Comparing our Ly$\alpha$ LF measurements with fourindependent reionization models, we estimate the neutral hydrogen fraction ofthe IGM to be $x_{\rm HI}=0.3\pm0.2$ at $z=$6.6 that is consistent with thesmall Thomson scattering optical depth obtained by Planck 2016.

SILVERRUSH. IV. Ly$\alpha$ Luminosity Functions at $z = 5.7$ and $6.6$ Studied with $\sim$ 1,300 LAEs on the $14-21$ deg$^2$ Sky