Radio to infrared spectra of late-type galaxies withPlanckandWilkinson Microwave Anisotropy Probedata

M. W. Peel, C. Dickinson, Rodney Davies, D. L. Clements, R. J. Beswick

    Research output: Contribution to journalArticlepeer-review


    We use thePlanckEarly Release Compact Source Catalogue combined withWilkinson Microwave Anisotropy Probe(WMAP) and other archival measurements to construct continuum spectra of three nearby dusty star-forming galaxies: Messier82, NGC253 and NGC4945. We carry out a least-squares fit to the spectra using a combination of simple synchrotron, free-free and thermal dust models, and look for evidence of anomalous microwave emission (AME). We find that the radio spectra of all three galaxies are consistent with steep spectrum synchrotron emission, with a significant amount of free-free emission required to explain thePlanckandWMAPdata points in the frequency range 30-150GHz. This brings the star formation rate based on free-free emission into better agreement with that from the non-thermal emission. We place limits on the presence of AME in these galaxies, finding that it is lower than expectations based on the ratio of far-infrared to AME from the Galaxy. Nevertheless, the shape of the spectrum of NGC4945 hints at the presence of AME with a peak around 30GHz. FuturePlanckdata will let us look more closely at these galaxies, as well as to extend the analysis to many more galaxies. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.
    Original languageEnglish
    Pages (from-to)L99-L103
    JournalMonthly Notices of the Royal Astronomical Society: Letters
    Issue number1
    Publication statusPublished - Sept 2011


    • Galaxies: individual: M82
    • Galaxies: individual: NGC253
    • Galaxies: individual: NGC4945
    • Galaxies: starburst
    • Radio continuum: galaxies
    • Submillimetre: galaxies


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