Probing the cold magnetized Universe with SPICA-POL (B-BOP)
Résumé
SPICA, the cryogenic infrared space telescope recently pre-selected for a "Phase A" concept study as one of the three remaining candidates for ESA's fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager (SPICA-POL, now called B-BOP), which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetized Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100-350 µm images of linearly polarized dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200 µm images will also have a factor ∼ 30 higher resolution than Planck polarization data. This will make B-BOP a unique tool for characterizing the statistical properties of the magnetized interstellar medium and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars. Preface The following set of articles describe in detail the science goals of the future Space Infrared telescope for Cosmol-ogy and Astrophysics (SPICA). The SPICA satellite will employ a 2.5-m telescope, actively cooled to below 8 K, and a suite of mid-to far-infrared spectrometers and photometric cameras, equipped with state-of-the-art detectors. In particular, the SPICA Far Infrared Instrument (SAFARI) will be a grating spectrograph with low (R = 300) and medium (R = 3000-11000) resolution observing modes instantaneously covering the 35-230 µm wavelength range. The SPICA Mid-Infrared Instrument (SMI) will have three operating modes: a large field of view (12 ×10) low-resolution 17-36 µm spectro-scopic (R = 50-120) and photometric camera at 34 µm, a medium resolution (R = 2000) grating spectrometer covering wavelengths of 18-36 µm and a high-resolution echelle module (R = 28000) for the 12-18 µm domain. A large-field-of-view (160 ×160) 1 , three-channel (100, 200, and 350 µm) polarimetric camera (B-BOP 2) will also be part of the instrument complement. These articles will focus on some of the major scientific questions that the SPICA mission aims to address; more details about the mission and instruments can be found in 1 Some other SPICA papers refer to this field of view as 80 ×80 , but it is 160 ×160 according to the latest design. 2 B-BOP stands for "B-fields with BOlometers and Polarizers".
Domaines
Astrophysique [astro-ph]| Origine | Fichiers produits par l'(les) auteur(s) |
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