ALMA disk imaging at band 10: [CI] and CO radial structures

We present resolved images of the HD100546 disk at ALMA band 10. Both CO 7-6 and [CI] 3P2-3P1 are bright and readily (simultaneously) imaged at 0.2arcsec resolution with relatively short integration times on ALMA. In order to study the molecular/atomic gas in this disk, the radial profiles and line widths of dust continuum, CO 7-6 and [CI] are compared with other transitions of both molecular and atomic species. We also compare these results with existing models. The HD100546 disk has a sharp outer edge in CO 3-2 at 440au, an order of magnitude larger than the mm dust ring. CO 7-6 has an excitation temperature 5x larger than 3-2, and not surprisingly, is found mostly at smaller radii, ~100au. Although [CI]2-1 excitation temperature is only 2x higher than CO 3-2, it too is mostly emitted from the ~100au region. We discuss the implications of this in terms of disk molecular/atomic structure.