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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present ALMA Band~7 observations at $850\mu$m of 20 luminous ($\log\,L_{\rm bol}>46.9$ [erg s$^{-1}$]) unobscured quasars at $z\sim2$. We detectcontinuum emission for 19/20 quasars. After subtracting an AGN contribution, wemeasure the total far-IR luminosity for 18 quasars, assuming a modifiedblackbody model, and attribute the emission as indicative of the star formationrate (SFR). Our sample can be characterized with a log-normal SFR distributionhaving a mean of 140 $M_\odot$ yr$^{-1}$ and a dispersion of 0.5 dex. Based onan inference of their stellar masses, the SFRs are similar, in both the meanand dispersion, with star-forming main-sequence galaxies at the equivalentepoch. Thus, there is no evidence for a systematic enhancement or suppression(i.e., regulation or quenching) of star formation in the hosts of the mostluminous quasars at $z\sim2$. These results are consistent with the Magneticumcosmological simulation, while in disagreement with a widely recognizedphenomenological model that predicts higher SFRs than observed here based onthe high bolometric luminosities of this sample. Furthermore, there is only aweak relation between SFR and accretion rate onto their supermassive blackholes both for average and individual measurements. We interpret these resultsas indicative of star formation and quasar accretion being fed from theavailable gas reservoir(s) in their host with a disconnect due to theirdifferent physical sizes, temporal scales, and means of gas processing.

No signs of star formation being regulated in the most luminous quasars at z~2 with ALMA