Identification of Spinning Dust in Halpha-Correlated Microwave Emission

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dc.creatorDobler, Gregory
dc.creatorFinkbeiner, Douglas P.
dc.date2007-12-13
dc.date2007-12-18
dc.date.accessioned2026-07-07T10:16:06Z
dc.date.available2026-07-07T10:16:06Z
dc.descriptionCMB experiments commonly use maps of Halpha intensity as a spatial template for Galactic free-free emission, assuming a power law I_nu \propto nu^-0.15 for the spectrum. Any departure from the assumed free-free spectrum could have a detrimental effect on determination of the primary CMB anisotropy. We show that the Halpha-correlated emission spectrum in the diffuse warm ionized medium (WIM) is not the expected free-free spectrum at WMAP frequencies. Instead, there is a broad bump in the spectrum at ~50 GHz which is consistent with emission from spinning dust grains. Spectra from both the full sky and smaller regions of interest are well fit by a superposition of a free-free and WIM Draine & Lazarian (1998) spinning dust model, shifted in frequency. The spinning dust emission is ~5 times weaker than the free-free component at 50 GHz, with the null hypothesis that the Halpha-correlated spectrum is pure free-free, ruled out at >8 sigma in all regions and >100 sigma for the full sky fit.
dc.description8 pages, 5 figures; submitted to ApJ; LaTeX modified slightly to reveal missing Figure 5
dc.identifierhttps://arxiv.org/abs/0712.2238
dc.identifierhttp://arxiv.org/abs/0712.2238
dc.identifierAstrophys.J.680:1235-1242,2008
dc.identifierdoi:10.1086/587863
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/173389
dc.subjectAstrophysics
dc.titleIdentification of Spinning Dust in Halpha-Correlated Microwave Emission
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