About: http://webisa.webdatacommons.org/367161095

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	A: Take a Mestel disc spiral galaxy with surface density S given by S=k / R (1) where R is the radius and k is a constant.
http://www.w3.org/ns/prov#wasQuotedFrom	physicsworld.com