A brightest cluster galaxy with an extremely large flat core

Marc Postman, Tod R. Lauer, Megan Donahue, Genevieve Graves, Dan Coe, John Moustakas, Anton Koekemoer, Larry Bradley, Holland C. Ford, Claudio Grillo, Adi Zitrin, Doron Lemze, Tom Broadhurst, Leonidas Moustakas, Begoña Ascaso, Elinor Medezinski, Daniel Kelson