Fuente, A.García-Burillo, S.Gerin, M.Usero, A.Teyssier, D.Rizzo Caminos, José Ricardo2016-08-182016-08-182005Fuente, A., García-Burillo, S., Gerín, M., Usero, A., Teyssier, D., & Rizzo, J. R. (2005). Chemical study of the giant PDR in the nucleus of M82: Detection of HOC+ in a starburst galaxy. In Proceedings of the Dusty and Molecular Universe: ESA Publications Division (pp. 281-282).929092855703796566http://hdl.handle.net/11268/5634The nucleus of M82 has been mapped in 3mm and 1mm lines of ON, HCN, C 2H, c-C3H2, CH3C2H, HC3N and the HOC+ using the IRAM 30m telescope. These species have been selected for constituting a good diagnostic of photon-dominated chemistry. We have measured [CN]/[HCN] ratios ≥ 5 in the inner 650 pc galaxy disk. Furthermore, we have detected the HOC+ 1→K) line with an intensity similar to that of the H13CO + 1→0 line. This implies a [HCO+]/[HOC+] ratio of ∼ 40. This low [HCO+]/[HOC+] ratio shows that the chemistry of the molecular gas reservoir in the nucleus of M82 is heavily influenced by the intense UV flux (G0 ∼ 104 in units of Habing field). Finally, the detection of the hydrocarbons c-C 3H2 and CH3C2H in the nucleus of M82 suggests that a complex carbon chemistry is developing in this giant photo-dissociation region (PDR).engjournal articlerestricted accessAstrofísicaAstronomíaMoléculas - InvestigaciónGalaxiasGalaxiaAstrofísicaFísica molecular