On the Interaction of a Bonnor–Ebert Sphere with a Stellar Wind

The structure of protostellar cores can often be approximated by isothermal Bonnor-Ebert spheres (BES) which are stabilized an external pressure. For the typical pressure $10^4k_B\,\mathrm{K\,cm^{-3}}$ to $10^5k_B\,\mathrm{K\,cm^{-3}}$ found in molecular clouds, with masses below $1.5\,{\rm M_\odot}$ stable against gravitational collapse. In this paper, we analyze efficiency triggering a collapse nearby stellar wind, represents interesting scenario for triggered low-mass star formation. We derive analytically new stability criterion BES compressed depends on its initial nondimensional radius $\xi_{max}$. If limit is violated wind triggers core Otherwise, destroyed wind. estimate validity range $2.5<\xi_{max}<4.2$ and confirm simulations SPH Code GADGET-3. trigger strongly decreases $\xi_{max}<2.5$ since case destruction acceleration whole sphere begin dominate. were unable $\xi_{max}<2$, leads conclusion that move smallest unstable mass $0.5\,\mathrm{M_\odot}$ destabilizing even smaller would require larger than $10^5k_B\,\mathrm{K\,cm^{-3}}$. $\xi_{max}>4.2$ expected strength according our small enough so compression slower sound speed waves triggered. underestimates somewhat onset detailed numerical analyses required.