capture vs track down

capture is a noun but track down is not a noun.

Word	Noun	Adjective	Verb	Adverb
capture	Yes	No	Yes	No
track down	No	No	Yes	No

As verbs, track down is a hyponym of capture; that is, track down is a word with a more specific, narrower meaning than capture:

Other hyponyms of capture include hunt, hunt down, run, frog, bag, batfowl, rat, ensnare, entrap, snare, trammel, trap.

capture (noun)	track down (noun)
the act of forcibly dispossessing an owner of property
the act of taking of a person by force
the removal of an opponent's piece from the chess board
any process in which an atomic or nuclear system acquires an additional particle
a process whereby a star or planet holds an object in its gravitational field

capture (verb)	track down (verb)
capture as if by hunting, snaring, or trapping	pursue for food or sport (as of wild animals)
succeed in catching or seizing, especially after a chase
succeed in representing or expressing something intangible
attract; cause to be enamored
take possession of by force, as after an invasion
bring about the capture of an elementary particle or celestial body and causing it enter a new orbit