The salvage system is a set of claws and mega melta-beams that hook onto a nearby ship and tear it to peices, so it can be stored inside the cruiser.  It takes one week and a difficult (-10) tech-use test to remove a component from a ship and store it aboard your own ship.  You can store 5 space worth of components in your stores, and also tow up to 20 space worth of components behind your vessel.   Each towed component inflicts a -1 speed penalty and a -5 maneuverability penalty.<br/><br/>As for the portal, it's probably where the ship went, but there's no way to know its nature.  If it's an Eldar webway portal, it'll end up moving after an hour or so, and be pretty much impossible to find.  If the Green Sun Princes use some other kind of spacial warping, its possible the portal will be stable.  (The great old ones were known for building stable portals, for example)