Destiny The Taken King introduces several new emblems and one of them is the Silent Scream Emblem. In order to get this emblem you have to launch patrol on Dreadnaught or do it during the 4th Taken King mission.
This adventure is much easier if you do it with a friend, because you have to Deploy Ghosts on two different consoles at the same time. Once you activate the consoles, a nearby door will open. The door leads towards the Bridge area where you should defeat all enemies. Proceed further and you will come across Ultra Knight boss. It’s pretty easy to defeat him. There is a fragment in the room with the Knight so have a good look around. It’s in the corner on your closest right as you come in.