Mission
PILOT (1) is a balloon-borne astronomy experiment being built to study the polarized emission arising from dust grains present in the diffuse interstellar medium in our Galaxy (see the Science Objectives page). Planned measurements will allow us to map the direction and intensity of the magnetic field in our Galaxy, as well as to learn about the magnetic properties of interstellar dust grains. It will also be possible to detect polarization in very diffuse regions in high galactic latitude interstellar clouds. The information obtained will be very useful to devise methods to subtract the contribution of polarized foreground emission for future cosmology missions aimed at measuring extensively the polarization of the Cosmic Microwave Background.
The experiment
The PILOT instrument will comprise a 1m primary mirror and a photometer for observations in two photometric channels at wavelengths of 240 and 550 microns with an angular resolution of a few arcminutes. We will make use of bolometer arrays, newly developed for the PACS instrument on board the Herschel
satellite. The large number of detectors per photometric channel (1024 for PILOT) and the wavelengths adapted to measure dust emission will contribute to make PILOT the most sensitive experiment ever for this type of measurements. An innovative method to measure polarization using arrays has been proposed. It will be validated by extensive simulations in the following months.
Les collaborations
PILOT is an international project involving contributions from French CNRS laboratories such as IRAP (2) and IAS (3), the CEA (4) and the CNES (5) with participations from foreign institutes (La Sapienza University in Rome -Italy-, Cardiff University -Walles-, the European Space Agency).
- CNES is responsible for funding, project management, responsability at system level and the development of the gondola and the day-time stellar sensor Estadius.
- IRAP is the Prime investigator of the experiment. It is responsible of setting the scientific requirements, definition of the flight plans and of the data processing of the calibration and in-flight data. It ensures the management of the scientific payload (the PILOT instrument).
- IAS is in charge of the management of the photometer.
- CEA is in charge of providing the detectors.
- Cardiff University provides submillimeter optical components: filters, HWP, lenses.
- University Rome La Sapienza is in charge of the design and realization of the cryostat and the half-wave plate rotation mechanism.
(1) Polarized Instrument for Long wavelength Observation of the Tenuous interstellar medium
(2) Institutde Recherche en Astrophysique et Planétologie
(3) Institut d'Astrophysique Spatiale d'Orsay
(4) Commissariat à l'Energie Atomique
(5) Centre National des Etudes Spatiales