Triggering Collapse of the Presolar Dense Cloud Core and Injecting Short-Lived Radioisotopes With a Shock Wave. I. Varied Shock Speeds

Who Pulled the Trigger: A Supernova or an Asymptotic Giant Branch Star?

“…However, these models led to considerably lower injection efficiencies than those previously estimated on the basis of models where the shock-cloud interaction was assumed to be isothermal (Boss 1995;Foster & Boss 1997;Vanhala & Boss 2002). When the injection efficiency (f i ) is defined to be the fraction of the incident shock wave material that is injected into the collapsing cloud core, values of f i ∼ 0.001 result from the nonisothermal models (Boss et al 2008(Boss et al , 2010, about 100 times lower than the values of f i found previously for strictly isothermal interactions.…”

“…Shock-triggered collapse and injection into the presolar cloud (Cameron & Truran 1977) has been proposed and studied in detail (e.g., Boss 1995;Foster & Boss 1997;Vanhala & Boss 2002;Boss et al 2008Boss et al , 2010. Recent calculations have shown that simultaneously triggered gravitational collapse and injection of shock wave gas and dust into the collapsing cloud core is possible even when detailed heating and cooling processes in the shock-cloud interaction are included (Boss et al 2008).…”

“…Recent calculations have shown that simultaneously triggered gravitational collapse and injection of shock wave gas and dust into the collapsing cloud core is possible even when detailed heating and cooling processes in the shock-cloud interaction are included (Boss et al 2008). Shock speeds in the range from 5 km s −1 to 70 km s −1 are capable of achieving simultaneous triggering and injection for a 2.2 M target cloud (Boss et al 2010). However, these models led to considerably lower injection efficiencies than those previously estimated on the basis of models where the shock-cloud interaction was assumed to be isothermal (Boss 1995;Foster & Boss 1997;Vanhala & Boss 2002).…”

Dust destruction in the ISM: a re-evaluation of dust lifetimes

“…Simulations of triggered star-formation relevant to the formation of the solar system (e.g., Boss et al 2010) indicate that shock-cloud encounters can lead to cloud collapse and star formation for shock velocities up to ∼70 km s −1 . A general finding of these simulations is that Rayleigh-Taylor instabilities at shock-cloud boundaries lead to a "shredding" of the cloud into cloudlets too small to collapse under their own gravity but still dense enough that the shock passes around them (e.g., Boss et al 2010).…”

“…A general finding of these simulations is that Rayleigh-Taylor instabilities at shock-cloud boundaries lead to a "shredding" of the cloud into cloudlets too small to collapse under their own gravity but still dense enough that the shock passes around them (e.g., Boss et al 2010).…”