Detection of anomalous microwave emission in the perseus molecular cloud with the cosmosomas experiment

R. A. Watson, R. Rebolo, J. A. Rubiño-Martín, S. Hildebrandt, C. M. Gutiérrez, S. Fernández-Cerezo, R. J. Hoyland, E. S. Battistelli

    Research output: Contribution to journalArticlepeer-review


    We present direct evidence for anomalous microwave emission in the Perseus molecular cloud, which shows a clear rising spectrum from 11 to 17 GHz in the data from the COSMOSOMAS experiment. By extending the frequency coverage using W ilkinson Microwave Anisotropy Probe maps convolved with the COSMOSOMAS scanning pattern, we reveal a peak flux density of 42 ± 4 Jy at 22 GHz integrated over an extended area of 1°.65 × 1°.0 centered on R.A. = 55°.4 ± 0°.1 and decl. = +31°.8 ± 0°.1 (J2000). The flux density that we measure at this frequency is nearly an order of magnitude higher than can be explained in terms of normal Galactic emission processes (synchrotron, free-free, and thermal dust). An extended IRAS dust feature, G159.6-18.5, is found near this position, and no bright unresolved source that could be an ultracompact H II region or gigahertz-peaked source could be found. An adequate fit for the spectral density distribution can be achieved from 10 to 50 GHz by including a very significant contribution from electric dipole emission from small spinning dust grains. © 2005. The American Astronomical Society. All rights reserved.
    Original languageEnglish
    Pages (from-to)L89-L92
    JournalAstrophysical Journal
    Issue number2
    Publication statusPublished - 10 May 2005


    • Diffuse radiation
    • Dust, extinction
    • ISM: individual (G159.6-18.5)
    • Radiation mechanisms: general
    • Radio continuum: ISM


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