The benefits of the Australian mixed mode program (2018 - 2023) for the celestial reference frame at S/X band

The current realization of the International Celestial Reference Frame at 8.4 GHz, the ICRF3-SX, is computed from Very Long Baseline Interferometry measurements starting in 1979 until March 2018. The concentration of the majority of VLBI telescopes in the Northern Hemisphere reflects itself in the unequal distribution of observations to radio sources over declination which causes the ICRF3-SX to be weaker in the south. One of the current VLBI observing programs active in the Southern Hemisphere is the Australian mixed-mode program (AUM) which started to be organized in July 2018. In this presentation, we show the benefits of the AUM for the celestial reference frame and also discuss its current limitations