HCO⁺ and N₂H⁺ as ionisation tracers in the low-mass protostar IRAS16293-2422

¹ Université de Toulouse, UPS-OMP, IRAP, Toulouse, France
² CNRS, IRAP, 9 Av. colonel Roche, BP. 44346, 31028 Toulouse Cedex 4, France

e-mail: dquenard@irap.omp.eu
e-mail: sbottinelli@irap.omp.eu
e-mail: ecaux@irap.omp.eu

Abstract

Ionisation in the molecular environment of star-forming regions gives important clues on the chemical processes that take place in the environment of a young protostar. Ionisation can be traced with molecules like HCO⁺ and N₂H⁺ and it regulates the formation of larger molecules such as complex organic molecules (COMs). The ionisation degree can also play an important role in the free-fall timescale of the protostar since it prevents the neutral material to collapse through collisions with ions and electrons bound to the magnetic field of the central protostar.