ALMA observations towards SM1. Left: 3 mm continuum observations of the SM1 disk. Right: Azimuthally averaged brightness temperature profile calculated using the full Planck function displayed in logarithmic scale. The corresponding 1σ uncertainties are shown in gray. Green dashed and solid vertical curves mark the same radial distance from the center in both panels, corresponding to the location of the deviation in the radial intensity profile and the location of the 3σ emission contour in the map, respectively.