| 201 | | The concluding remarks go like this -- in each of the cases, key observational features are reproduced, namely the velocity fields. If then the collapse was triggered by a compression wave in those observational cases, then the Pext increased on such and such timescales. They go on to talk about the significance of the results in terms of compression wave solutions of Whitworth in the 3rd paragraph on page 881. They say, they generation of a uniform inward velocity field appears to be a general feature of compression wave solutions (again - I did not see this generated in their simulations from their plots), and that ALL OF THE INFINITY OF WHITWORTH SOLUTIONS involve a compression wave being driven from outside - in, leaving behind them vrad~constant and a 1/r^2^ density envelope. This needs to be clarified -- is this vrad (R,t) = constant or is this vrad(r,T) = constant? Moreoever, they say that the convergence of this wave on the center signifies the formation of the protostar - and that it accretes at a constant rate, developing an outward traveling expansion wave that travels outward from protostar, leaving in its wake a v~r^-1/2^ and rho~r^-3/2^! He says Shu's solution is one limiting case of this behavior - of a 0 amplitude compression wave leaving behind a uniform v=0 velocity field. I am unsure though if the constant accretion rate is in fact a general feature of the Whitworth solution, as I have always heard that referred to in conjunction with the Shu solution. It is hard to connect that accretion rate constant business to the Hennebelle results and others, given the accretion rates decline over time. Why they didn't clarify this, I am not sure... |
| | 201 | The concluding remarks go like this -- in each of the cases, key observational features are reproduced, namely the velocity fields. If collapse was triggered by a compression wave for the observational cases cited in the intro, then the Pext increased on such and such timescales. They go on to talk about the significance of the results in terms of compression wave solutions of Whitworth in the 3rd paragraph on page 881. They say, the generation of a uniform inward velocity field appears to be a general feature of compression wave solutions (again - I did not see this generated in their simulations from their plots), and that ALL OF THE INFINITY OF WHITWORTH SOLUTIONS involve a compression wave being driven from outside - in, leaving behind them vrad~constant and a 1/r^2^ density envelope. This needs to be clarified -- is this vrad (R,t) = constant or is this vrad(r,T) = constant? Moreover, they say that the convergence of this wave on the center signifies the formation of the protostar - and that it accretes at a constant rate, developing an outward traveling expansion wave that leaves in its wake a v~r^-1/2^ and rho~r^-3/2^! He says Shu's solution is one limiting case of this behavior - of a 0 amplitude compression wave leaving behind a uniform v=0 velocity field. I am unsure though if the constant accretion rate is in fact a general feature of the Whitworth solution, as I have always heard that referred to in conjunction with the Shu solution. It is hard to connect the constant accretion rate to the Hennebelle results and others, given the accretion rates decline over time. Why they didn't clarify this, I am unsure... |
