University of Milano-Bicocca
A survey of polarized dust emission by BLAST Observatory to address the MHD turbulence properties in the ISM and the physical properties of dust composition
The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) Observatory is a proposed 1.8 meter off-axis telescope that maps linearly polarized dust emission at 175, 250 and 350 μm. Operating at more than 30 Km altitude (more than 99.5% of the Earth’s atmosphere) from an ultra-long duration stratospheric balloon platform, the BLAST Observatory will create large-area (tens of degree squares), detailed (best resolution 25′′) maps of magnetic fields and diffuse interstellar medium (ISM), and it will address key outstanding mysteries that have high priority for the Galactic far-IR/sub-mm astronomy community. BLAST will probe the properties of magnetohydrodynamic (MHD) turbulence in the ISM, which couples density, velocity, and magnetic fields across scales. BLAST will explore the dominant mechanism that causes the energy injected into the ISM to cascade down a hierarchy of physical scales until dissipation. Furthermore, BLAST will determine whether one or more distinct populations of dust exist, and characterize the evolution of intrinsic dust properties from diffuse gas to cold cores, revealing the mechanical, chemical, and thermodynamic processes that shape interstellar grains. BLAST Observatory will also characterize polarized dust emission between 175-350 μm, and it will target diffuse regions of sky that overlap with Cosmic Microwave Background (CMB) experiments, providing high-frequency constraints on the polarized dust foreground to the CMB. Finally, the BLAST collaboration pioneered the concept that balloon missions should be observatories available to the entire community, and 30% of the BLAST Observatory flight will be dedicated to shared risk programs, for observing proposals from the astronomy community.