Pilot optical alignment

PILOT (Polarized Instrument for Long wavelength Observations of the Tenuous interstellar medium) is a balloonborne astronomy experiment designed to study the polarization of dust emission in the diffuse interstellar medium in our Galaxy. The PILOT instrument allows observations at wavelengths 240 μm (1.2THz) with an angular resolution about two arc-minutes. The observations performed during the first flight in September 2015 at Timmins, Ontario Canada, have demonstrated the optical performances of the instrument

PILOT: measuring the FIR astrophysical dust emission

Measuring precisely the faint polarization of the Far-Infrared and sub-millimetre sky is the next observational challenge of modern astronomy. In particular, detection the B-mode polarization from the Cosmic Microwave Background (CMB) shall reveal the inflationary periods in the very early universe. Such measurements will require very high sensitivity and very low instrumental systematic effects. As for measurements of the CMB intensity, sensitive measurements of the CMB polarization will be made difficult by the presence of foreground emission from our own Milky Way, which is orders of magnitude higher than the faint polarized cosmological signal. Such foreground emission will have to be understood very accurately and removed from cosmological measurements. This polarized emission is also interesting in itself, since it brings information relevant to star formation processes, about the orientation of the magnetic field in our Galaxy through the alignment of dust grains. I will first summarize our current knowledge in this field. I will then describe the PILOT balloon-borne experiment project, which is dedicated to measuring precisely the polarization of faint diffuse dust emission in the Far-Infrared in our Galaxy

PILOT end-to-end calibration results

The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium (PILOT) is a balloon-borne astronomy experiment designed to study the linear polarization of the Far Infra-Red emission, 240 ~im (1.2 THz) and 550 ~tm (545 GHz) with an angular resolution of a few minutes of arc, from dust grains present in the diffuse interstellar medium, in our Galaxy and nearby galaxies. The polarisation of light is measured using a half-wave plate (HWP). We performed the instrumental tests from 2012 to 2014 and are planning a first scientific flight in September 2015 from Timmins, Ontario, Canada. This paper describes the measurement principles of PILOT, the results of the laboratory tests and its sky coverage. These include defocus tests, transmission measurements using a Fourier Transform Spectrometer at various positions of the HWP, and identification of internal straylight

PILOT end-to-end calibration results

The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium (PILOT) is a balloon-borne astronomy experiment designed to study the linear polarization of the Far Infra-Red emission, 240 ~im (1.2 THz) and 550 ~tm (545 GHz) with an angular resolution of a few minutes of arc, from dust grains present in the diffuse interstellar medium, in our Galaxy and nearby galaxies. The polarisation of light is measured using a half-wave plate (HWP). We performed the instrumental tests from 2012 to 2014 and are planning a first scientific flight in September 2015 from Timmins, Ontario, Canada. This paper describes the measurement principles of PILOT, the results of the laboratory tests and its sky coverage. These include defocus tests, transmission measurements using a Fourier Transform Spectrometer at various positions of the HWP, and identification of internal straylight