Hot potatoes: the compact obscured nuclei of dusty IR galaxies

Evidence is now mounting that most of the activity in some luminous infrared galaxies takes place in their compact obscured nuclei (CONs), regions of less than 100~pc in diameter, which harbor large amounts of warm (T$>$100~K) molecular material (N(H$_2$)$>10^{24}$~cm$^{-2}$). The combined effect of warm, shielded gas and intense infrared radiation produce rich molecular spectra, which make these objects unique laboratories to study molecular excitation in extreme environments. Also, recent studies have shown that such compact nuclei may drive extremely young (1-2 Myr) molecular outflows, and are thus ideal targets to study AGN/starburst feedback processes. 
Here I will present some first results from Cycle~0 observations of two obscured nuclei. In the prototypical CON of NGC~4418 we proposed a 170~GHz-wide spectral scan in bands 3, 6 and 7, aimed at obtaining a template for the molecular chemistry and excitation in CONs. In NGC~1377, the galaxy with the highest far-IR/radio ratio observed to date, we successfully mapped the molecular outflow in CO 1-0 and obtained the first detection of the continuum at wavelengths $>$1~mm. What is driving the outflow, and why is NGC~1377 so radio-deficient ?
10/10/2013 - 14:30
Dr. Francesco Costagliola
IAA-CSIC, Radioastronomy and galactic structure group