Detalles de publicación
PP 06029
Polarization Observations of the anomalous microwave emission in the Perseus molecular complex with the COSMOSOMAS experiment
(1) IAC, (2) CSIC, (3) Jodrell Bank Observatory
The anomalous microwave emission detected in the Perseus molecular
complex by Watson et al. has been observed at 11 GHz through
dual orthogonal polarizations with the COSMOSOMAS experiment.
Stokes U and Q maps are obtained at a resolution of
~0.9 deg for a 30º x 30º region including
the Perseus Molecular complex.
Faint polarized emission has been measured; we find Q=-0.2% +/- 1.0%
and U=(-3.4 +1.8 -1.4)%, both at the 95% confidence level,
with a systematic uncertainty estimated to be lower than 1% determined from
tests of the instrumental
performance using unpolarized sources in our map as null hypothesis.
The resulting total polarization level is $\Pi = 3.4^{+1.5}_{-1.9}%$.
These are the first constraints on the polarization properties of an anomalous
microwave emission source. The low level of polarization seems to indicate that
the particles responsible for this emission are not significantly aligned in a common
direction over the whole region, as a consequence of either a high structural symmetry
in the emitting particle or a low-intensity magnetic field. Our weak detection is
fully consistent with predictions from electric dipole emission and resonance relaxation
at this frequency.
complex by Watson et al. has been observed at 11 GHz through
dual orthogonal polarizations with the COSMOSOMAS experiment.
Stokes U and Q maps are obtained at a resolution of
~0.9 deg for a 30º x 30º region including
the Perseus Molecular complex.
Faint polarized emission has been measured; we find Q=-0.2% +/- 1.0%
and U=(-3.4 +1.8 -1.4)%, both at the 95% confidence level,
with a systematic uncertainty estimated to be lower than 1% determined from
tests of the instrumental
performance using unpolarized sources in our map as null hypothesis.
The resulting total polarization level is $\Pi = 3.4^{+1.5}_{-1.9}%$.
These are the first constraints on the polarization properties of an anomalous
microwave emission source. The low level of polarization seems to indicate that
the particles responsible for this emission are not significantly aligned in a common
direction over the whole region, as a consequence of either a high structural symmetry
in the emitting particle or a low-intensity magnetic field. Our weak detection is
fully consistent with predictions from electric dipole emission and resonance relaxation
at this frequency.