Maps of Toomre’s Q parameter towards MMS1a and b. The color scale indicates the value of Toomre’sQ parameter, where blue is Toomre-stable, yellow is critical, and red regions are gravitationally unstable against axisymmetric perturbations, where the level of Q_crit = 1 is indicated by the red dashed contours. The black contours indicate the 5, 10, 15, 20σ continuum emission levels and increase further in steps of 20σ, where σ = 0.28 mJy beam⁻¹. The solid and dashed gray ellipses show the deprojected radii of the disks with diameter 4300 and 8600 au, respectively. The black diamonds in the MMS1a panels mark the positions of the emission peaks at 3.6 cm (Rodríguez et al. 2012). Top panels: Q parameter maps of the two cores for the rotating disk structures seen almost face-on (i = 10°). Motivated by the disk inclination estimate of i_MMS1b ~ 80° (Rodríguez et al. 2012), we also present maps for such disk inclinations (bottom panels) and intermediate values (i = 45°, middle panels). For the deprojection process, the angles of the disk major axes of ϕ_maj,MMS1a ≈ 240° and ϕ_maj,MMS1b ≈ 230° (relative to the north–south axis, see text) were used. The shaded ellipse in the lower right corner indicates the synthesized beam of the CH₃CN data of 0.42′′ × 0.35′′ (PA 61°).