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

Event rate of long Gamma-Ray Bursts (GRBs) is expected to be an useful tracerof the cosmic star-formation history. For this purpose, it is necessary tounderstand what kind of star formations/galaxies are traced by GRBs. Here wereport rest-frame far-infrared (FIR) continuum detections of GRB 070521 and080207 host galaxies at $z\sim2$ with ALMA band 8 and 9. The FIR photometriesprovide the reliable star-formation rates (SFRs), because FIR emission is freefrom dust extinction and possible radio contamination from long-livedafterglows of GRBs. The spectral energy distribution fittings indicate49.85$^{+72.33}_{-2.86}$ and 123.4$^{+25.19}_{-21.78}$ $M_{\odot}$ yr$^{-1}$for the 070521 and 080207 hosts, respectively. The derived SFRs place them onthe \lq \lq main sequence\rq \rq\ of normal star-forming galaxies at $z\sim2$.The derived SFRs are significantly lower than that of radio observations. It isinferred that the observed radio fluxes in a previous study are contaminated bythe afterglows. ALMA marginally detected [C~{\sc ii}]\,158\,$\mu$m emissionline from the GRB 080207 host galaxy with S/N $\sim$ 4. This is the firstdetection of [C~{\sc ii}]\,158\,$\mu$m of a GRB host at $z>2$, and the seconddetection among known GRBs. The luminosity ratio of [C~{\sc~ii}]\,158$\mu$m toFIR is 7.5$\times 10^{-4}$, which is one of the smallest values among galaxiesat $z\sim 1-2$ with the same FIR luminosity. The \lq \lq [C~{\sc ii}]deficit\rq \rq\ could be a new physical property to characterise GRB hosts at$z\sim1-2$. Possible parameters controlling the deficit include themetallicity, initial mass function, and gas density.

Star-formation rates of two GRB host galaxies at z~2 and a [CII] deficit observed with ALMA