Description |
We propose to use HIFI to observe a complete set of molecular ions related tothe PDR-XDR-CRs chemistry toward seven galaxies covering all types ofactivities. We have selected the hydrides CH+, CH, OH, H2O+, HCl, OH+ andH3O+, and the high density tracers HCN, HCO+ and HNC suggested to beaffected by X-ray and shock induced chemistry. To covera 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 twostarbursts, 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. |