Far-IR polarized emission in the Crab Nebula with SOFIA/HAWC+

We present detection of dust polarized emission of the Crab Nebula (M 1) in the far-infrared, from SOFIA/HAWC+ observations, at 89 and 154 μm. After removing the signal from synchrotron emission, including its polarized component, we compute the average dust-only polarization in three dusty filaments, ranging from ∼ 3 - 9%. We constrain the grain temperatures and masses, assuming mixtures of silicate- and carbon-rich grains, using laboratory properties. Upper limits on the total dust mass in the Crab Nebula range from 0.027 to 1.0 M_⊙, and a fraction of carbon grains ranging from 0.2 to 70%.