Not necessarily. Cosmic rays are just electromagnetic energy on particular (high) frequencies. So if it interprets everything along those lines, it's just seeing everything purely in terms of the EM spectrum... in other words 'normal, uninteresting background case, free of cosmic rays'. So things that don't trigger high enough to be cosmic rays, like itself, parse as meaningless random fluctuations... presumably, if it was 'intelligent', it would think that it existed for no reason, as a matter of random chance, like any other case of background radiation below the threshold of cosmic rays, without losing any ability to perceive or understand cosmic rays.