CO and PAH⁺/PAH⁰/VSG maps in external galaxies

¹ Department of Physics and Astronomy of University College London, Gower Street, London W1W 6HD, UK
² Centre d'Étude Spatiale des Rayonnements, 9 Av. du Colonel Roche, BP. 44346, 31028 Toulouse Cedex 4, France
³ Laboratoire de Radioastronomie de L'École Normale Supérieure-LERMA-Observatoire de Paris, 24 rue Lhomond, 75231 Paris Cedex 05, France
⁴ Observatorio Astronómico Nacional, Observatorio de Madrid, Alfonso XII3, 28014 Madrid, Spain

Abstract

We have performed a comparison between the molecular gas emission and the mid IR dust component emission distributions in a sample of nearby galaxies. We have compared CO maps at high spatial resolution, from Wilson et al. (2000), Bayet et al. (2004, 2006) and from Kramer et al. (2005), with the emission distributions of ionised and neutral PAHs (PAH⁺; PAH⁰) and of very small grains (VSGs), obtained using signal processing methods as explained in Berné et al. (2007a) and Rapacioli et al. (2005). In M 82, we have also compared the dust emission maps with dense gas tracer maps (HCO and H¹³CO⁺ data from García-Burillo et al. 2002) as well as with shock tracer maps (SiO data from García-Burillo et al. 2001).