Credit: Pixabay/CC0 Public Domain As "Michael," a major biographical film on Michael Jackson, hits cinemas more than a decade and a half after the singer's death, a new study shows that dead artists' brands remain powerful long after they are gone. It's a phenomenon Graham King, producer of the upcoming Michael Jackson movie knows instinctively. He also produced Freddie Mercury's biopic, "Bohemian Rhapsody," which made more than $900m (1.25 billion AUD) at the box office and won four Oscars. It comes off the back of the February release of Baz Luhrmann's EPiC "Elvis Presley in Concert," a follow up of Luhrmann's 2022 Elvis movie. Now, revealing research from Australia's Macquarie University in collaboration with UNSW has investigated the social media engagement with 10 major celebrities, including Elvis Presley, Marilyn Monroe, Emma Watson and Beyoncé. Prof Dr.…