Flux density F^v originating from hot dust for the system HD 172167 (Vega). The black crosses denote the values inferred from the observations (see Table 2). The orange line shows the radiation of a carbonaceous dust ring reproducing the observed flux densities with an inner disk radius of R_in = 0.18 au, a population of grains with radius a_S = 0.2 µm and a dust mass of M_S ≈ 6.2 × 10⁻¹⁰ M_⊕, and a population of larger grains with radius a_L = 10 µm and a dust mass of M_L ≈ 8.9 × 10⁻¹⁰ M_⊕; the dashed lines in blue and red denote the respective contributions of the two grain populations. For comparison, the solid green line depicts the radiation of a dust ring at the same location comprised of grains made of astronomical silicate with a grain radius of a = 0.2 µm; the dust mass is scaled such that the flux density matches the value inferred from observations at λ = 2.13 µm. This dust ring does not reproduce the observations due to the high predicted flux density in the MIR wavelength range.