Warm Molecular Hydrogen in the Galactic Wind of M82

We report the detection of a complex of extraplanar warm H₂ knots and filaments extending more than ~3 kpc above and below the galactic plane of M82, roughly coincident with the well-known galactic wind in this system. Comparisons of these data with published results at other wavelengths provide quantitative constraints on the topology, excitation, heating, and stability against disruption of the wind-entrained molecular interstellar matter in this prototypical galactic wind. Deep H₂ 2.12 μm observations such as these represent a promising new method to study the elusive but potentially important molecular component of galactic winds.

This work is based on observations carried out with the facilities of NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under cooperative agreement with the National Science Foundation.