A Complete ALMA Map of the Fomalhaut Debris Disk

We present ALMA mosaic observations at 1.3. mm (223 GHz) of the Fomalhaut system with a sensitivity of 14 mu Jy/beam. These observations provide the first millimeter map of the continuum dust emission from the complete outer debris disk with uniform sensitivity, enabling the first conclusive detection of apocenter glow. We adopt an MCMC modeling approach that accounts for the eccentric orbital parameters of a collection of particles within the disk. The outer belt is radially confined with an inner edge of 136.3 +/- 0.9. au and width of 13.5 +/- 1.8. au. We determine a best-fit eccentricity of 0.12 +/- 0.01. Assuming a size distribution power-law index of q. =. 3.46 +/- 0.09, we constrain the dust absorptivity power-law index a to be 0.9 更多