The First Measurements of the Electron Density Enhancements Expected in C-Type Shocks

摘要: Magnetic precursors of C-type shocks accelerate, compress, and heat molecular ions, modifying the kinematics physical conditions ion fluid with respect to neutral one. Electron densities are also expected be significantly enhanced in shock precursors. In this Letter, we present observations strongly polar molecules such as SiO, H13CO+, HN13C, H13CN, which reveal electron density enhancements associated precursor young L1448-mm outflow. While ambient gas excitation ions neutrals is explained by collisional H2 a single ~105 cm-3, H13CO+ shows an overexcitation component that requires factor ≥10 larger than those derived from species. This can if consider additional collisions electrons enhancement stage ~500, i.e., fractional ionization 5 × 10-5. These results show multiline used study evolution fluids at first stages interaction.