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 investigate the stellar population of star-forming galaxies at $z \sim 4$by focusing on their slope of rest-frame ultraviolet (UV) continuum, $\beta$where $f_{\lambda} \propto \lambda^{\beta}$. We investigate the sample ofbright Lyman Break Galaxies (LBGs) with $i' \leq 26.0$ in the Subaru/XMM-NewtonDeep Survey field by using the SED fitting analysis. We find that theapparently redder ($\beta_{\mathrm{obs}} > -1.73$) LBGs tend to be dusty($\mathrm{Av} > 1.0$), have the young stellar population ($\beta_{\mathrm{int}}< -2.42$), and the intrinsically active star-forming galaxies (SFR $\gtrsim$ afew $\times 10^{2}$ $\mathrm{M_{\odot}} \mathrm{yr^{-1}}$). It means that asignificant fraction of the UV-selected LBGs at $z \sim 4$ is on-going activeand dust obscured star-forming galaxies. We compare the IR to UV luminosityratio assuming the dust attenuation laws with the sub-millimeter observationsfrom previous works. The result suggests that the Calzetti-like dustattenuation law is preferable for the active and dusty star-forming LBGs at $z= 4$. We also find that an extrapolation of the$\beta_{\mathrm{int}}$-$M_{\mathrm{UV,int}}$ relation toward the faintermagnitude range below our sample magnitude limit intersects the$\beta_{\mathrm{obs}}$-$M_{\mathrm{UV,obs}}$ relation previously obtained inthe deeper narrow-area observations at $M_{\mathrm{UV}} = -18.9$ and $\beta =-1.94$, which coincides with the break point of$\beta_{\mathrm{obs}}$-$M_{\mathrm{UV,obs}}$ relation observed so far. Thecoincidence suggest that we see the almost dust-free population at$M_{\mathrm{UV,obs}} \gtrsim -18.9$.

The UV spectral slope beta and stellar population of most active star-forming galaxies at z~4