Modelling the chemistry of star forming filaments - H$_2$ and CO
  chemistry
  We present simulations of star forming filaments incorporating on of the
largest chemical network used to date on-the-fly in a 3D-MHD simulation. The
network contains 37 chemical species and about 300 selected reaction rates. For
this we use the newly developed package KROME (Grassi et al. 2014). We combine
the KROME package with an algorithm which allows us to calculate the column
density and attenuation of the interstellar radiation field necessary to
properly model heating and ionisation rates. Our results demonstrate the
feasibility of using such a complex chemical network in 3D-MHD simulations on
modern supercomputers. We perform simulations with different strengths of the
interstellar radiation field and the cosmic ray ionisation rate. We find that
towards the centre of the filaments there is gradual conversion of hydrogen
from H to H$_2$ as well as of C$^+$ over C to CO. Moreover, we find a decrease
of the dust temperature towards the centre of the filaments in agreement with
recent HERSCHEL observations.
