of the radial coordinate of AdS space. This way an extra energy parameter $ 1/z_0 $, associated with an ultraviolet (UV) energy scale is introduced in the model. The masses and decay constants of charmonium and bottomonium $S$ wave states are calculated in ref. [@Braga:2015jca] using the quantity $ 1/z_0 $ as a flavour independent parameter and taking the usual infrared (IR) soft wall parameter $k$ to depend on the flavor, since it is associated with the quark mass. A total of eight masses and eight decay constants are determined using three parameters. The rms error is of $30 \% $ that is reasonable, given the simplicity of the model and the fact that two different properties of two different flavors are adjusted with just 3 parameters.

The purpose of the present article is to extend the model of ref. [@Braga:2015jca] to finite temperature in order to investigate the thermal spectra of $S$ wave states of charmonium and bottomonium. We will show that the spectral functions present the expected behavior: at low temperatures, sharp peaks for the lower level excitations, and, as the temperature increases, the peaks spread and decrease in height. The evolution of the spectral function with increasing 