IR spectra acquired during warm-up of previously irradiated H₂S ice. This band is evidence of the presence of H₂S_x molecules with x > 2 that were detected during desorption in the gas phase by QMS, H₂S₃, and H₂S₄ desorbing at temperatures below 225 K (see Fig. 4). Therefore, the small IR absorption that remains above 240 K is likely due to H₂S_x species with x > 4 that are refractory at this temperature and could thus not be detected by the QMS.