Phonon background versus analog Hawking radiation in Bose-Einstein condensates

We determine the feasibility of detecting analog Hawking radiation in a Bose-Einstein condensate in the presence of atom-loss-induced heating. We find that phonons created by three-body losses overshadow those due to analog Hawking radiation. To overcome this problem, three-body losses may have to be suppressed, for example, as proposed by Search [Phys. Rev. Lett. 92, 140401 (2004)]. The reduction of losses to a few percent of their normal rate is typically sufficient to suppress the creation of loss phonons on the time scale of fast analog Hawking phonon detection.