Who is Dr. Gibarian from Solaris and what is their importance?

Dr. Gibarian was a Solarist. He was in charge of Station Solaris, and when Kelvin arrived at the station at the beginning of the novel, he learned that Gibarian was dead. Gibarian is said to have committed suicide, and his body was being kept in the station's deep freeze. Kelvin found that Gibarian's corpse was being guarded by a large black woman clothed only in a native skirt. Presumably, this "ghost" is one of the planet Solaris's creations, based on a deeply rooted memory in Gibarian's brain.