QUIJOTE scientific results – V. The microwave intensity and polarization spectra of the Galactic regions W49, W51 and IC443
| Autor: | D Tramonte, R T Génova-Santos, J A Rubiño-Martín, P Vielva, F Poidevin, C H López-Caraballo, M W Peel, M Ashdown, E Artal, R B Barreiro, F J Casas, E de la Hoz, M Fernández-Torreiro, F Guidi, D Herranz, R J Hoyland, A N Lasenby, E Martinez-Gonzalez, L Piccirillo, R Rebolo, B Ruiz-Granados, F Vansyngel, R A Watson |
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| Rok vydání: | 2023 |
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| Zdroj: | Monthly Notices of the Royal Astronomical Society. 519:3432-3459 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | We present new intensity and polarisation maps obtained with the QUIJOTE experiment towards the Galactic regions W49, W51 and IC443, covering the frequency range from 10 to 20 GHz at $\sim$ 1 deg angular resolution, with a sensitivity in the range 35-79 ${\mu}$K/beam for total intensity and 13-23 ${\mu}$K/beam for polarisation. For each region, we combine QUIJOTE maps with ancillary data at frequencies ranging from 0.4 to 3000 GHz, reconstruct the spectral energy distribution and model it with a combination of known foregrounds. We detect anomalous microwave emission (AME) in total intensity towards W49 at 4.7${\sigma}$ and W51 at 4.0${\sigma}$ with peak frequencies ${\nu}_{AME}$ = (20.0 $\pm$ 1.4) GHz and ${\nu}_{AME}$ = (17.7 $\pm$ 3.6) GHz respectively; this is the first detection of AME towards W51. The contamination from ultra-compact HII regions to the residual AME flux density is estimated at 10% in W49 and 5% in W51, and does not rule out the AME detection. The polarised SEDs reveal a synchrotron contribution with spectral indices ${\alpha}_s$ = -0.67 $\pm$ 0.10 in W49 and ${\alpha}_s$ = -0.51 $\pm$ 0.07 in W51, ascribed to the diffuse Galactic emission and to the local supernova remnant respectively. Towards IC443 in total intensity we measure a broken power-law synchrotron spectrum with cut-off frequency ${\nu}_{0,s}$ = (114 $\pm$ 73) GHz, in agreement with previous studies; our analysis, however, rules out any AME contribution which had been previously claimed towards IC443. No evidence of polarised AME emission is detected in this study. Comment: 29 pages, 11 figures. Accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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