Aims. We observed four nearby spiral galaxies (NGC 3627, NGC 4254, NGC 4736 and NGC 5055) in the K band with the 64-m Sardinia Radio Telescope, with the aim of detecting the Anomalous Microwave Emission (AME), a radiation component presumably due to spinning dust grains, observed so far in the Milky Way and in a handful of other galaxies only (most notably, M 31). Methods. We mapped the galaxies at 18.6 and 24.6 GHz and studied their global photometry together with other radio-continuum data from the literature, in order to find AME as emission in excess of the synchrotron and thermal components. Results. We only find upper limits for AME. These non-detections, and other upper limits in the literature, are nevertheless consistent with the average AME emissivity from the few detections: it is AME 30 GHz = 2.4±0.4×10^-2 MJy sr^-1 (M pc^-2 ) −1 in units of dust surface density (equivalently, 1.4 ± 0.2 × 10^-18 Jy sr^-1 (H cm^-2 )^-1 in units of H column density). We finally suggest to search for AME in quiescent spirals with relatively low radio luminosity, such as M 31.

Published in Astronomy & Astrophysics, Volume 658, id.L8, 11 pp.