Continuum emission maps at 1.3 mm of the AB Aur region. Top panels: larger scale image obtained from the SMA data (left panel) and the residual image after removing the emission detected by the PdBI (right panel). Contour levels are −2, 2, 4, 6, 8, 10 to 80 by 10  ×  1 mJy per 74  ×  44 beam. Bottom panels: higher angular resolution images obtained with the PdBI. Left panel: the blue, red, and black pluses mark the peaks of CO 2-1 highest blue-shifted, red-shifted peak, and the stellar location, respectively. The black cross marks the northeast peak of the 1.3 mm continuum. The dotted contours mark the intensity of 2σ_I, where σ_I = 0.23 mJy per 052  ×  037 beam. Black contours start from 4σ_I in steps of 2σ_I. Middle panel: residual emission from the PdBI after removal of a best-fit smooth ring. The inner and outer radii are indicated. Contour levels are multiples of 2σ_I. Right panel: the solid white ellipse marks the 1.3 mm peak ring with a radius of 145 AU, i of 23° and PA of −30° centered on the 1.3 mm stellar peak. The blue and red contours mark the CO 2-1 emission starting from and stepping in 66 mJy per 056  ×  042 beam at the velocity channels of 2 and 9.3 km s^-1, respectively. The 3.6 cm continuum emission are in thick black contours at the level 3, 6, 9, 12, 15 × 9.3   μJy per 027  ×  026 beam. The synthesized beam of 1.3 mm and 3.6 cm are labeled as black and white ellipses in the lower left corner, respectively.