Molecular Gas in the Merging System ARP 299

We present new observations of the molecular gas distribution in the merging system Arp 299. The first observation set was obtained with the Canada-France-Hawaii Telescope near-IR camera Redeye and the second set comes from the IRAM Plateau de Bure interferometer (combined with short spacings observed at the IRAM 30 m Telescope). In the near IR, H^sub 2^ ν=1[arrow right]0 S(1) and Br^sub γ^ line maps are globally identical: there is bright emission not only at the two galaxy nuclei but also in numerous extranuclear star forming regions. Moreover, there is weaker emission localized in filaments between and around the two nuclei. These filaments correspond to a dust lane observed in optical images from HST. ^sup 12^CO(1[arrow right]0), ^sup 13^CO(1[arrow right]0) and HCN(1[arrow right]0) maps are also presented. The structure of the^sup 12^CO(1[arrow right]0) map is very close to the NIR observations: the same bright galaxy nuclei and star-forming regions, the same filaments, but half of the total flux is found in weak extended emission. Strong HCN emission is observed in the nucleus A indicating the presence of a large amount of dense gas. Nucleus B1 is weak in ^sup 12^CO(1[arrow right]0) emission while nucleus A and star-forming regions C-C' show more normal ^sup 13^CO/^sup 12^CO ratios.[PUBLICATION ABSTRACT]