Assertion: black hole's galaxy | /r/HasProperty | held by supermassive black holes
Facets:
value: together
type: MANNER
value: at their centers
type: LOCATION
Source sentences:
text: It is now thought that most galaxies are held together by supermassive black holes at their centers, which cluster hundreds of solar systems around them.
text: It confirms that large galaxies like Virgo A (and the Milky Way) are held together by supermassive black holes, Doeleman said.