TY - JOUR
T1 - QUIJOTE scientific results - V. The microwave intensity and polarization spectra of the Galactic regions W49, W51 and IC443
AU - Tramonte, D.
AU - Génova-Santos, R.~T.
AU - Rubiño-Martin, J.~A.
AU - Vielva, P.
AU - Poidevin, F.
AU - López-Caraballo, C.~H.
AU - Peel, M.~W.
AU - Ashdown, M.
AU - Artal, E.
AU - Barreiro, R.~B.
AU - Casas, F.~J.
AU - de la Hoz, E.
AU - Fernández-Torreiro, M.
AU - Guidi, F.
AU - Herranz, D.
AU - Hoyland, R.~J.
AU - Lasenby, A.~N.
AU - Martinez-Gonzalez, E.
AU - Piccirillo, L.
AU - Rebolo, R.
AU - Ruiz-Granados, B.
AU - Vansyngel, F.
AU - Watson, R.~A.
PY - 2023/3/1
Y1 - 2023/3/1
N2 - We present new intensity and polarization maps obtained with the QUIJOTE experiment towards the Galactic regions W49, W51 and IC443, covering the frequency range from 10 to 20 GHz at ∼1deg angular resolution, with a sensitivity in the range 35-79 μKbeam−1 for total intensity and 13-23 μKbeam−1 for polarization. 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 4.7σ and W51 at 4.0σ with peak frequencies νAME=(20.0±1.4)GHz and νAME=(17.7±3.6)GHz , respectively; this is the first detection of AME towards W51. The contamination from ultracompact H II regions to the residual AME flux density is estimated at 10 per cent in W49 and 5 per cent in W51, and does not rule out the AME detection. The polarized SEDs reveal a synchrotron contribution with spectral indices αs = -0.67 ± 0.10 in W49 and αs = -0.51 ± 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 ν0,s=(114±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 polarized AME emission is detected in this study.
AB - We present new intensity and polarization maps obtained with the QUIJOTE experiment towards the Galactic regions W49, W51 and IC443, covering the frequency range from 10 to 20 GHz at ∼1deg angular resolution, with a sensitivity in the range 35-79 μKbeam−1 for total intensity and 13-23 μKbeam−1 for polarization. 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 4.7σ and W51 at 4.0σ with peak frequencies νAME=(20.0±1.4)GHz and νAME=(17.7±3.6)GHz , respectively; this is the first detection of AME towards W51. The contamination from ultracompact H II regions to the residual AME flux density is estimated at 10 per cent in W49 and 5 per cent in W51, and does not rule out the AME detection. The polarized SEDs reveal a synchrotron contribution with spectral indices αs = -0.67 ± 0.10 in W49 and αs = -0.51 ± 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 ν0,s=(114±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 polarized AME emission is detected in this study.
KW - radiation mechanisms: general
KW - ISM: individual objects: W49
KW - W51
KW - IC443
KW - radio continuum: ISM
KW - Astrophysics - Astrophysics of Galaxies
KW - Astrophysics - Cosmology and Nongalactic Astrophysics
U2 - 10.1093/mnras/stac3502
DO - 10.1093/mnras/stac3502
M3 - Article
VL - 519
SP - 3432
EP - 3459
JO - mnras
JF - mnras
IS - 3
ER -