Accretion diagnostic as a function of disk hole size for transition disk candidates. (a) Mass accretion rates are from UV excess (preferentially) (Venuti et al. 2014) and from Hα equivalent width (Sousa et al. 2016). For WTTS, we fix the value of the mass accretion rate at 1 × 10⁻¹¹ M_⊙ yr⁻¹. The upside down triangles correspond to the upper limits of the mass accretion rate. The dashed line represents the region where the inner hole can be explained by X-ray photoevaporation (Owen et al. 2011, 2017). Only ∼18% of our sample of transition disk candidates can be explained by X-ray photoevaporation of the inner disk by stellar radiation. (b) UV emission excess (Venuti et al. 2014). (c) Hα equivalent width (Sousa et al. 2016; Dahm & Simon 2005). Gray filled symbols identify systems that fall in the region where the inner disk hole can be explained by X-ray photoevaporation.