Residual time series (left) and GLS periodogram (right) after subtracting the GP + Keplerian model to the TZ Ari RV data (grey). The 10%, 1%, and 0.1% FAP levels are indicated by dashed orange lines. The stellar rotation period (1.96 d) is shown in purple, the newly derived planetary orbital period (789.92 d) is in light blue, and the two signals exceeding the 1% FAP level (37.2 d and 41.4 d) are marked in black. These likely correspond to stellar activity given the significant (40.18 d) periodicity observed in the FWHM and g₂ indicators.