Cold Dust and its Heating Sources in M 33

We have mapped the nearby face-on spiral galaxy M 33 in the 1.1 mm dust continuum using AzTEC on Atacama Submillimeter Telescope Experiment (ASTE). The preliminary results are presented here. The observed dust has a characteristic temperature of ~ 21 K in the central kpc, radially declining down to ~ 13 K at the edge of the star forming disk. We compare the dust temperatures with K_S band flux and star formation tracers. Our results imply that cold dust heating may be driven by long-lived stars even nearby star forming regions.