The closest thing to a badge of honor. These masterwork sidearms are awarded to exceptional senior Guardians of the Vanguard; often those who have at least a few decades of service. These Guardians are assigned the "Operator" status. They are posted in high-risk patrol zones to act as point-of-contact for other Guardians and Pilgrim Guards. In addition, they act as instructors for New Lights on fieldwork and in shaping their powers.
It's often thanks in part to the work of Operators that the recklessness of fresh immortals don't result in a higher RTL toll.
A fun fact is that the Operators are mostly comprised of Hunters.
The crafting of these Operator Pistols is an arduous task, requiring a large investment of paracausal energy and rare golden age scrap in order to create. Experienced Guardians are assigned "Artemis Components" to carry around and are encouraged to utilize their Light as much as possible while undergoing their missions.
These components will steadily absorb the stray paracausal energy until it begins to show anomalous qualities, to which then it is brought back to the gunsmiths in order to create the main part of the pistol, the Artemis System.
To this day, the Artemis System remains some of the most heavily guarded secrets of the Vanguard. Only the Vanguard leaders of each class, Cryptarch masters, and Gunsmith masters are privy to its existence as well as the means to create it. Although, it is said that a certain rat has been looking into "getting his hands on that doohickey."