The Local Hot Bubble

The solar system resides in the Local Hot Bubble (LHB) with a size scale of 100 pc, which also produces bright X-ray emission. Although LHB is irregular in shape, it is thought to have a uniform temperature of ∼0.1 keV. Its intensity, unattenuated by the Galactic absorption, varies across the sky. Its elemental abundances are largely unknown. Some fractions of O, Mg, Si, and Fe might be locked up in dust, but the exact dust depletion fraction is poorly constrained.