We argue that a type IIB Euclidean supergravity solution of the form ℝ × S1 × 8 with imaginary self-dual F1 flux through ℝ × S1 belongs to the chain of AdSd × Sd × 10−2d vacua with (imaginary) self-dual Fd flux, where d ≤ 5. Such vacua come from the near-horizon of D(d − 2)/D(8 − d) branes and are supersymmetric for odd values of d. For d = 1 we speculate that the hallmark of conformal symmetry for the matrix model dual is a vanishing free energy. The matrix dual was recently constructed by [1] by adding matrix interactions coming from strings stretching between the D(−1) and D7 branes to the IKKT matrix model. We find that the corresponding supergravity solution indeed has vanishing on-shell action. Specific F5 fluxes need to be switched on as a consequence of (a T-dual version of) the Hanany-Witten effect
