Continuum maps of Sgr B2 at 850 μm, with a synthesized beam of 024, PA = 14.4° (lower-right corner in each panel). The left panel shows the image of Sgr B2(N), with contour levels (− 1, 1, ...14) × 4σ (1σ = 0.031 Jy beam^-1). The cross symbols indicate the positions of UC Hii regions detected in 1.3 cm continuum (Gaume et al. 1995). The right panel presents the image of Sgr B2(M), with contour levels (− 1, 1, 2, 3, 4, 4.5, 5.5, 5, 6, 7, 8, 10, ...28)  ×  4σ (1σ = 0.021 Jy beam^-1). The cross symbols indicate the positions of UC Hii regions detected in 7 mm continuum (de Pree et al. 1998). In each panel, the filled circle symbols present the peak positions of the submillimeter continuum sources.