IPT2018-Problem6- Sonic Black Hole (Federal University of ABC, Brazil)

IPT2018 Problem 6 Sonic Black Hole Federal University of ABC: A sonic black hole is a phenomenon in which sound is unable to escape a region of space which is not bounded by any walls. Just the same as for usual black holes where light is unable to escape some region of spacetime. Try to create your own sonic black hole. What represents the event horizon? Does the Hawking radiation exist for your black hole model? Which properties of usual black holes cannot be represented?