2008A&A...485..679P

We present new radio observations of two regions of the spiral galaxy NGC3627, including new radio continuum observations at 1.4GHz with the Very Large Array, and also new observations in the CO line, taken with the Plateau de Bure interferometer. Comparing these observations with archival Spitzer and H_α data we study the correlation of the radio continuum (RC), infrared-8µm, and CO emissions at a spatial resolution of 100pc. We compare the point-by-point variations of the RC, CO, and 8 µm brightnesses in two distinct regions of 2 kpcx2 kpc in size of NGC3627. We also present a three-dimensional fit of the observed data. We examined scale much lower than the electron diffusion scale, where a breakdown of the correlations would be expected. However, no evidence for such correlation breakdown has been found. The RC emission follows the distribution of CO well, and the widths of several structures, measured along slices across them, are comparable. Furthermore, we found that down to a spatial scale of 100 pc, the radio continuum emission is correlated with dust emissions at 4.5, 5.8, and 8µm, which trace different dust temperatures. We present a new perspective, a three-dimensional representation, with which to visualize and study the RC-CO-24µm and RC-CO-8µm correlations. We fit the observed data with a three-dimensional line, obtaining a rms of 0.25dex. The observed correlation enhances the complexity of the electrons diffusion, losses, and injection mechanisms, and of their connection to star formation processes described by molecular and dust emissions. We plan to further investigate this connection using spatially resolved spectral index studies at low radio frequencies where the thermal emission component is seemingly negligible.