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 report detection of radio recombination line (RRL) H$_{40\alpha}$ toward75 sources, with data obtained from ACA observations in the ATOMS survey of 146active Galactic star forming regions. We calculated ionized gas mass and starformation rate with H40U line emission. The mass of ionized gas issignificantly smaller than molecular gas mass, indicating that ionized gas isnegligible in the star forming clumps of the ATOMS sample. The star formationrate (SFR$_{{\rm H}_{40\alpha}}$) estimated with RRL H$_{40\alpha}$ agrees wellwith that (SFR$_{\rm L_{bol}}$) calculated with the total bolometric luminosity(L$_{\rm bol}$) when SFR $\gtrsim 5 {\rm M_\odot My}r^{-1}$, suggesting thatmillimeter RRLs could well sample the upper part of the initial mass function(IMF) and thus be good tracers for SFR. We also study the relationships betweenL$_{\rm bol}$ and the molecular line luminosities (L0mol) of CS J=2-1 andHC$_3$N J=11-10 for all the 146 ATOMS sources. The Lbol-L0mol correlations ofboth the CS J=2-1 and HC3N J=11-10 lines appear approximately linear and thesetransitions have success in predicting L$_{\rm bol}$ similar to that of morecommonly used transitions. The L$_{\rm bol}$-to-L$_{\rm mol}$ ratios orSFR-to-mass ratios (star formation efficiency; SFE) do not change withgalactocentric distances (R$_{\rm GC}$). Sources with H$_{40\alpha}$ emission(or H$_{\rm II}$ regions) show higher L$_{\rm bol}$-to-L$_{\rm mol}$ than thosewithout H$_{40\alpha}$ emission, which may be an evolutionary effect.

monthly notices of the royal astronomical society

ATOMS: ALMA Three-millimeter Observations of Massive Star-forming  regions -- IV. Radio Recombination Lines and evolution of star formation  efficiencies