Detection of doubly deuterated ammonia in L134N

ND2H has been detected for the first time in the dense core of L134N, at th e peak ammonia position. The abundance ratio [ND2H]/[NH2D] is 0.05, a sligh tly smaller value than the deuterium fractionation observed for ammonia [NH 2D]/[NH3] similar to 0.1 (Tine et al. 2000). This is the second doubly deut erated species detected so far in the interstellar medium, and the first on e in a cold dense core. The chemical processes leading to the formation of a significant amount of doubly deuterated ammonia ND2H need to be thorougly investigated.