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Despite considerations of mass loss from stellar evolution suggestingotherwise, the content of gas in globular clusters seems poor and hence itsmeasurement very elusive. One way of constraining the presence of ionized gasin a globular cluster is through its dispersive effects on the radiation of themillisecond pulsars included in the cluster. This effect led Freire et al. in2001 to the first detection of any kind of gas in a globular cluster in thecase of 47 Tucanae. By exploiting the results of 12 additional years of timing,as well as the observation of new millisecond pulsars in 47 Tucanae, werevisited this measurement: we first used the entire set of available timingparameters in order to measure the dynamical properties of the cluster and thethree-dimensional position of the pulsars. Then we applied and tested variousgas distribution models: assuming a constant gas density, we confirmed thedetection of ionized gas with a number density of $n= 0.23\pm 0.05$ cm$^{-3}$,larger than the previous determination (at 2$\sigma$ uncertainty). Modelspredicting a decreasing density or following the stellar distribution densityare highly disfavoured. We are also able to investigate the presence of anintermediate mass black hole in the centre of the cluster, showing that is notrequired by the available data, with an upper limit for the mass at $\sim 4000$M$_{\odot}$.

Internal gas models and central black hole in 47 Tucanae using millisecond pulsars