Christopher Tibbs

 

Spitzer characterisation of dust in an anomalous emission region: the Perseus Cloud

N. Flagey, R. Paladini, M. Compiègne, S. Shenoy, S. Carey, A. Noriega-Crespo, C. Dickinson, Y. Ali-Haïmoud, S. Casassus, K. Cleary, R. D. Davies, R. J. Davis, C. M. Hirata, R. A. Watson

 

Microwave observations throughout our Galaxy have identified the existence of a new Galactic emission mechanism known as anomalous microwave emission. This anomalous microwave emission has been found to be highly spatially correlated with the dust, and one of the most promising candidates to explain this emission is electric dipole radiation from rapidly rotating very small dust grains, commonly referred to as spinning dust. Anomalous microwave emission has previously been detected in the Perseus cloud. Photometric data obtained with Spitzer have been reprocessed and used in conjunction with the dust emission model DUSTEM to characterise the properties of the dust within the cloud. This analysis has allowed us to constrain spatial variations in the strength of the interstellar radiation field (χISRF), the abundances of the Polycyclic Aromatic Hydrocarbons (PAHs) and Very Small Grains (VSGs) relative to the Big Grains (YPAH and YVSG), the column density of hydrogen and the equilibrium dust temperature. The parameter maps of YPAH, YVSG and χISRF are the first of their kind to be produced for the Perseus cloud, and we used these maps to investigate the physical conditions in which anomalous emission is observed.