The Critical Metallicity for Low-Mass Star Formation through Fine-Structure Line Cooling

Low-mass stars, the kind that can survive to the present day, require gas to fragment on small scales. This study computes the relevant quantities from stated assumptions and compares them with published values. The headline results are: Zcrit Zsun = 3.16e-04; Zcrit absolute = 4.43e-06; metal mass in 1e5 Msun cloud Msun = 0.443; carbon mass Msun = 0.080; single SN metal yield Msun = 2.0; margin factor = 5. A cloud of one hundred thousand solar masses at the critical metallicity contains less than half a solar mass of metals in total, and well under a tenth of a solar mass of carbon. The study is simulated and computed, not measured, and its negative findings, where the computation does not support an effect, are reported at the same prominence as its positive ones.