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 introduce a simple model to explore the star formation histories of diskgalaxies. We assume that the disk origins and grows by continuous gas infall.The gas infall rate is parametrized by the Gaussian formula with one freeparameter: infall-peak time $t_p$. The Kennicutt star formation law is adoptedto describe how much cold gas turns into stars. The gas outflow process is alsoconsidered in our model. We find that, at given galactic stellar mass $M_*$,model adopting late infall-peak time $t_p$ results in blue colors, lowmetallicity, high specific star formation rate and high gas fraction, while gasoutflow rate mainly influences the gas-phase metallicity and star formationefficiency mainly influences the gas fraction. Motivated by the local observedscaling relations, we construct a mass-dependent model by assuming low massgalaxy has later infall-peak time $t_p$ and larger gas outflow rate thanmassive systems. It is shown that this model can be in agreement with not onlythe local observations, but also the observed correlations between specificstar formation rate and galactic stellar mass $SFR/M_* \sim M_*$ atintermediate redshift $z<1$. Comparison between the Gaussian-infall model andexponential-infall model is also presented. It shows that theexponential-infall model predicts higher star formation rate at early stage andlower star formation rate later than that of Gaussian-infall. Our resultssuggest that the Gaussian infall rate may be more reasonable to describe thegas cooling process than the exponential infall rate, especially for low-masssystems.

The mass-dependent star formation histories of disk galaxies: infall model versus observations