An intermediate sized black-hole.
BHs of mass 10^2–10^5 M⊙, more massive than stellar mass BHs and lighter than supermassive BHs (SMBHs), are traditionally designated IMBHs. A conclusive observation of these objects has thus far remained elusive, despite indirect evidence.
GW190521: A Binary Black Hole Merger with a Total Mass of 150 M⊙ (solar mass).
P.S.: The paper has two software citations, inc. #matplotlib 😄
This podcast episode covers it in detail.
Science Friday: Medium Black Holes, World of Wonders, Warsaw Typhus. Sept 11, 2020, Part 2 https://www.sciencefriday.com/episodes/september-11-2020/
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