Spectrum of the Anomalous Microwave Emission in the North Celestial Pole with WMAP 7-Year data

Abstract

We estimate the frequency spectrum of the diffuse anomalous microwave emission (AME) on the North Celestial Pole (NCP) region of the sky with the Correlated Component Analysis (CCA) component separation method applied to WMAP 7-yr data. The NCP is a suitable region for this analysis because the AME is weakly contaminated by synchrotron and free-free emission. By modeling the AME component as a peaked spectrum we estimate the peak frequency to be $21.7\pm 0.8$\,GHz, in agreement with previous analyses which favored ${\nu }_{\mathrm{p}}<23$\,GHz. The ability of our method to correctly recover the position of the peak is verified through simulations. We compare the estimated AME spectrum with theoretical spinning dust models to constrain the hydrogen density $n_{\mathrm{H}}$. The best results are obtained with densities around 0.2--0.3\,cm${}^{-3}$, typical of warm ionised medium (WIM) to warm neutral medium (WNM) conditions. The degeneracy with the gas temperature prevents an accurate determination of $n_{\mathrm{H}}$, especially for low hydrogen ionization fractions, where densities of a few cm${}^{-3}$ are also allowed.

13 pages, 6 figures, published in Advances in Astronomy

References in corpus (5)

• Extended Anomalous Foreground Emission in the WMAP 3-Year Data
• Separation of anomalous and synchrotron emissions using WMAP polarization data
• A refined model for spinning dust radiation
• WMAP 3yr data with the CCA: anomalous emission and impact of component separation on the CMB power spectrum
• Correlated Component Analysis for diffuse component separation with error estimation on simulated Planck polarization data

Cited by in corpus (1)

• Foreground removal for Square Kilometre Array observations of the Epoch of Reionization with the Correlated Component Analysis