  The detection of the redshifted cosmological $21$~cm line signal requires the
removal of the Galactic and extragalactic foreground emission, which is orders
of magnitude brighter anywhere in the sky. Foreground cleaning methods
currently used are efficient in removing spectrally smooth components. However,
they struggle in the presence of not spectrally smooth contamination that is,
therefore, potentially the most dangerous one. An example of this is the
polarized synchrotron emission, which is Faraday rotated by the interstellar
medium and leaks into total intensity due to instrumental imperfections. In
this work we present new full-sky simulations of this polarized synchrotron
emission in the $50-200$~MHz range, obtained from the observed properties of
diffuse polarized emission at low frequencies. The simulated polarized maps are
made publicly available, aiming to provide more realistic templates to simulate
the effect of instrumental leakage and the effectiveness of foreground
separation techniques.
