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We present ~0.4 resolution images of CO(3-2) and associated continuumemission from the gas-bearing debris disk around the nearby A star 49 Ceti,observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). Weanalyze the ALMA visibilities in tandem with the broad-band spectral energydistribution to measure the radial surface density profiles of dust and gasemission from the system. The dust surface density decreases with radiusbetween ~100 and 310 au, with a marginally significant enhancement of surfacedensity at a radius of ~110 au. The SED requires an inner disk of small grainsin addition to the outer disk of larger grains resolved by ALMA. The gas diskexhibits a surface density profile that increases with radius, contrary to mostprevious spatially resolved observations of circumstellar gas disks. While ~80%of the CO flux is well described by an axisymmetric power-law disk in Keplerianrotation about the central star, residuals at ~20% of the peak flux exhibit adeparture from axisymmetry suggestive of spiral arms or a warp in the gas disk.The radial extent of the gas disk (~220 au) is smaller than that of the dustdisk (~300 au), consistent with recent observations of other gas-bearing debrisdisks. While there are so far only three broad debris disks with wellcharacterized radial dust profiles at millimeter wavelengths, 49 Ceti's diskshows a markedly different structure from two radially resolved gas-poor debrisdisks, implying that the physical processes generating and sculpting the gasand dust are fundamentally different.

Radial Surface Density Profiles of Gas and Dust in the Debris Disk around 49 Ceti