Non- central/ semi-detached

The consequence of this is that there is a cross-national tendency for the museums sector to be both politically non-central and, quite commonly, a semi-detached part of the overall political system, free to operate in its own way as long as this does not negatively impinge on the larger political and ideological expectations and requirements of national, regional and local governments.

what does non-central mean?

what does a semi-detached part mean?