Two neutron stars on a collision course?

What exactly will happen when two neutron stars are on a collision
course? I think a supernova and black hole is inevitable if both
neutron stars are very heavy. But what about smaller ones? Will they
merge? Or be torn into thousands of "pieces" from the impact? Another
theory is gamma ray bursts with huge amounts of mass converted into
energy. Expert opinion?

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Matt Browne
My webpage is at http://www.meet-matt-browne.com
"As a race, we survive on planet Earth purely by geological consent."
Bill McGuire