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QUIJOTE Scientific Results - XVII. Studying the anomalous microwave emission in the Andromeda Galaxy with QUIJOTE-MFI

Abstract: The Andromeda Galaxy (M31) is the Local Group galaxy that is most similar to the Milky Way (MW). The similarities between the two galaxies make M31 useful for studying integrated properties common to spiral galaxies. We use the data from the recent QUIJOTE-MFI Wide Survey, together with new raster observations focused on M31, to study its integrated emission. The addition of raster data improves the sensitivity of QUIJOTE-MFI maps by almost a factor 3. Our main interest is to confirm if anomalous microwave emission (AME) is present in M31, as previous studies have suggested. To do so, we built the integrated spectral energy distribution of M31 between 0.408 and 3000 GHz. We then performed a component separation analysis taking into account synchrotron, free?free, AME, and thermal dust components. AME in M31 is modelled as a log-normal distribution with maximum amplitude, AAME, equal to 1.03 ± 0.32 Jy. It peaks at ?AME = 17.2 ± 3.2 GHz with a width of WAME = 0.58 ± 0.16. Both the Akaike and Bayesian information criteria find the model without AME to be less than 1 per cent as probable as the one taking AME into consideration. We find that the AME emissivity per 100 ?m intensity in M31 is ?AME28.4 GHz = 9.6 ± 3.1 ?K MJy?1 sr, similar to that of the MW. We also provide the first upper limits for the AME polarization fraction in an extragalactic object. M31 remains the only galaxy where an AME measurement has been made of its integrated spectrum.

 Fuente: Monthly Notices of the Royal Astronomical Society, 2024, 527(4), 11945-11961

 Publisher: Oxford University Press

 Publication date: 23/12/2023

 No. of pages: 17

 Publication type: Article

 DOI: 10.1093/mnras/stad3145

 ISSN: 0035-8711,1365-2966

 Spanish project: AYA2007-68058-C03-01

 Publication Url: https://doi.org/10.1093/mnras/stad3145

Authorship

FERNÁNDEZ-TORREIRO, M.

GÉNOVA-SANTOS, R.T.

RUBIÑO-MARTÍN, J.A.

LÓPEZ-CARABALLO, C.H.

PEEL, M.W.

ARCE-TORD, C.

ELENA DE LA HOZ LOPEZ-COLLADO

HOYLAND, R.

LASENBY, A.

PICCIRILLO, L.