First detection of polarization of the submillimetre diffuse galactic dust emission by Archeops

Abstract

Richard Gispert passed away few weeks after his return from the early mission to Trapani. Abstract. We present the first determination of the Galactic polarized emission at 353 GHz by Archeops. The data were taken during the Arctic night of February 7, 2002 after the balloon-borne instrument was launched by CNES from the Swedish Esrange base near Kiruna. In addition to the 143 GHz and 217 GHz frequency bands dedicated to CMB studies, Archeops had one 545 GHz and six 353 GHz bolometers mounted in three polarization-sensitive pairs that were used for Galactic foreground studies. We present maps of the I, Q, U Stokes parameters over 17% of the sky and with a 13 arcmin resolution at 353 GHz (850 µm). They show a significant Galactic large scale polarized emission coherent on the longitude ranges [100, 120] and [180, 200] deg. with a degree of polarization at the level of 4-5%, in agreement with expectations from starlight polarization measurements. Some regions in the Galactic plane (Gem OB1, Cassiopeia) show an even stronger degree of polarization in the range 10-20%. These findings provide strong evidence for a powerful grain alignment mechanism throughout the interstellar medium and a coherent magnetic field coplanar to the Galactic plane. This magnetic field pervades even some dense clouds. Extrapolated to high Galactic latitude, these results indicate that interstellar dust polarized emission is the major foreground for PLANCK-HFI CMB polarization measurements.

Planck2015 results

“…17 and 24). Compared with earlier ground-based and balloon-borne observations (e.g., Benoît et al 2004;Ward-Thompson et al 2009;Matthews et al 2009Matthews et al , 2014Koch et al 2010) this survey is an immense step forward in sensitivity, coverage, and statistics. It provides new insight into the structure of the Galactic magnetic field and the properties of dust, as well as the first statistical characterization of one of the main foregrounds to CMB polarization.…”

The pre-launchPlanckSky Model: a model of sky emission at submillimetre to centimetre wavelengths

“…So far, dust polarisation measurements have mostly concentrated on specific regions of emission, with the exception of the Archeops balloon-borne experiment (Benoît et al 2004), which has mapped the emission at 353 GHz over 17 percent of the sky, showing a polarisation fraction around 4-5% in the Galactic plane, and up to 10-20% in some clouds. Recently, polarisation of dust emission at 100 and 150 GHz has been observed by BICEP over a smaller region of the Galactic plane (Matsumura et al 2010) and by QUaD (Culverhouse et al 2010).…”

A cryogenic waveplate rotator for polarimetry at mm and submm wavelengths

“…The experiment is optimized to perform surveys of the polarized dust emission along the Galactic plane but also at high Galactic latitudes, where previous experiments have provided only upper limits (Benoit et al 2004;Ponthieu et al 2005). PILOT will probe the large-scale distribution of the Galactic magnetic field and the alignment properties of the dust grains, providing strong constraints for dust models, in particular via the dependence on frequency of the degree of polarization.…”

“…The dashed line represents rms CMB anisotropy for ΔT/T = 10 −5 . The dash-dotted line represents the spectrum of the polarized signal from a dust cloud with brightness of 1 mK RJ at 353 GHz and 10% polarization (see Benoit et al 2004). The symbols mark the frequency bands explored by forthcoming polarization measurements from several experiments: Planck (up triangles), PILOT (squares), BLAST-Pol (stars), SPIDER (circles), EBEX (diamonds), SCUBA2 (down triangles), SOFIA (upgraded HAWC: pentagons).…”