Observation of thermal Hawking radiation and its temperature in an analogue black hole

<!--HTML--><p><span style="color:#1f497d">We study the Hawking radiation in an analogue black hole, in which sound plays the role of light.&nbsp; We find that the correlation spectrum of Hawking radiation agrees well with a thermal spectrum, and its temperature is given by the surface gravity.&nbsp; This confirms the predictions of Hawking’s theory.&nbsp; The Hawking radiation is in the regime of linear dispersion, in analogy with a real black hole.&nbsp; Furthermore, the radiation inside of the analogue black hole is seen to be composed of negative-energy partners only.</span></p>