On the fraction of star formation occurring in bound stellar clusters

摘要: We present a theoretical framework in which bound stellar clusters arise naturally at the high-density end of hierarchy interstellar medium (ISM). Due to short free-fall times, these regions achieve high local star formation efficiencies, enabling them form clusters. Star-forming lower density remain substructured and gas-rich, ending up unbound when residual gas is expelled. Additionally, tidal perturbation star-forming by nearby, dense giant molecular clouds imposes minimum contrast required for collapse cluster. The fraction all that occurs (the cluster efficiency, hereafter CFE) follows integration clustering survival properties over full spectrum ISM, hence set galaxy-scale physics. derive CFE as function observable galaxy properties, find it increases with surface density, from Γ ∼ 1 per cent low-density galaxies peak value 70 densities Σg 103 M⊙ pc−2. This explains observation rate nearby dwarf, spiral starburst galaxies. Indeed, comparing our model results observed yields excellent agreement. applied further calculating spatial variation within single also consider cosmic time show redshift, peaking high-redshift, gas-rich disc It estimated 30–35 stars Universe once formed discuss how theory can be verified Gaia ALMA, provide possible implementations work simulations evolution.