Protostellar outflows: a window to the past

During the early phases of low-mass star formation, episodic accretion causes ejection high-velocity outflow bullets, which carry a fossil record driving protostar's history. We present 44 SPH simulations $1\,\mathrm{M}_{\odot}$ cores, covering wide range initial conditions, and follow cores for five free-fall times. Individual protostars are represented by sink particles, particles launch outflows using subgrid model. The Optics algorithm is used to identify individual bullets within outflows. parameters overall then estimate age energetics outflow, events that triggered it; evaluate how reliable these estimates are, if observational uncertainties selection effects (like inclination) neglected. Of commonly methods estimating ages, it appears those based on length speed advance lobe most in evolution, width cavity during later phases. describe new method almost as accurate methods, throughout evolution. In addition we show history protostar can be accurately reconstructed from dynamics each contains at least two bullets. entrain about ten times more mass than originally ejected protostar.