| Description |
We propose to use HIFI to observe a complete set of molecular ions related to
the PDR-XDR-CRs chemistry toward seven galaxies covering all types of
activities. We have selected the hydrides CH+, CH, OH, H2O+, HCl, OH+ and
H3O+, and the high density tracers HCN, HCO+ and HNC suggested to be
affected by X-ray and shock induced chemistry. To cover
a wide range of nuclear activity we will observe three ULIRGs, Arp 220 (cold),
NGC4418 (warm) and Mrk231, one LIRG, Arp 299A, the AGN NGC1068, and two
starbursts, M82 and M83.
The high spectral resolution provided by HIFI will be fundamental to disentangle
the complex line profiles (usually P Cygni) often observed in galaxies due
to clouds observed along the line of sight with different velocities and
large changes in the molecular abundances ratios. The H2O, OH+,
H2O+ and H3O+ abundances and abundance ratios will be used to
disentangle the CR/Xray and the PDR components in the galaxies. |
