Sheng-Jun Lin (NTHU, Taiwan); Shih-Ping Lai (NTHU, Taiwan); Laurent Pagani (Observatoire de Paris, France)
We estimate the age of a starless core, L1512, in the Taurus molecular cloud with ortho-H2D+ (110-111) and multiple transitions of N2H+, N2D+ and DCO+ using GBT, JCMT, and IRAM 30 m telescope. L1512 is chosen because it is globular-shaped and relatively isolated in the Taurus molecular cloud, providing an ideal environment for studying the target properties. In order to estimate the age of the starless cores, we have applied a technique to measure the deuteration ratio profile of a H-carrier (best species is N2H+) across the core. With the help of time-dependent chemical models, we can compare the observations to an evolutionary model and constrain the age of the cores.