Hot gas flows on global and nuclear galactic scales

One of the most significant observational improvements allowed by the high quality Chandra data of galaxies is the measurement of the nuclear luminosities down to low values, and of the hot ISM properties down to very low gas contents. I present here some recent developments concerning the possibility of accreting and outflowing gas, based on modeling results that take into account the role of a central supermassive black hole (MBH).