| Popis: |
We discuss the evolution and the fragmentation of cylindrical gas clouds with primordial composition, using the virial equation. Comparing the timescale of collapse with that of fragmentation, we obtain the fragment mass scale for the various initial density. We estimate the minimum mass of a fragment that is formed from the primordial gas cloud. The mass scale is essentially determined by the Chandrasekhar mass. The effect of dark matter is also investigated. If the filamentary cloud consists not only of ordinary gas but also some dark matter, the fragmentation of the cylindrical cloud occurs at the lower density than the pure gas case. As a result, the fragment mass scale hardly becomes Chandrasekhar mass scale. In this case, massive star formation is strongly expected. |
