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 condition for the formation of low-mass second-generationstars in the early universe. It has been proposed that gas cooling by dustthermal emission can trigger fragmentation of a low-metallicity star-forminggas cloud. In order to determine the critical condition in which dust coolinginduces the formation of low-mass stars, we follow the thermal evolution of acollapsing cloud by a one-zone semi-analytic collapse model. Earlier studiesassume the dust amount in the local universe, where all refractory elements aredepleted onto grains, and/or assume the constant dust amount during gascollapse. In this paper, we employ the models of dust formation and destructionin early supernovae to derive the realistic dust compositions and sizedistributions for multiple species as the initial conditions of our collapsecalculations. We also follow accretion of heavy elements in the gas phase ontodust grains, i.e., grain growth, during gas contraction. We find that graingrowth well alters the fragmentation property of the clouds, and that thisstill does not approach to the value in the local universe. The criticalconditions can be written by the gas metallicity Zcr and the initial depletionefficiency fdep,0 of gas-phase metal onto grains, or dust-to-metal mass ratio,as (Zcr/10^{-5.5} Zsun) = (fdep,0/0.18)^{-0.44} with small scatters in therange of Zcr = [0.06--3.2]x10^{-5} Zsun. We also show that the initial dustcomposition and size distribution are important to determine Zcr.

Supernova dust formation and the grain growth in the early universe: The critical metallicity for low-mass star formation