Lyman-

Lyman-α nebulae are typically found in massive environments at high redshift (z ≳ 2). The origin of their Lyman-α (Lyα) emission remains debated. Recent polarimetric observations showed that at least some Lyα sources are polarized. This is often interpreted as proof that the photons are centrally produced and contradicts the scenario in which the Lyα emission is the cooling radiation emitted by gas that is heated during the accretion onto the halo. We suggest that this cooling radiation scenario is compatible with the polarimetric observations. To test this idea, we post-processed a radiative hydrodynamics simulation of a blob with the MCLy