Modeled Keplerian ellipse orbits over H¹³CN (J = 4–3) channel maps at typical CND velocities v_LSR from −100 to +150 km s⁻¹ (left) and over higher-velocity ¹²CO (J = 3–2) channel maps (right). Green contours show the [Ne II]12.8 μm emission from ionized gas streamers (Irons et al. 2012). The red orbit segments show the expected location of the gas according to the best-fit orbital parameters of Zhao et al. (2009) for the ionized gas (standard mass model). The blue orbit segments are for a model in which the dynamical mass (M in Eq. (2)) is multiplied by 3.