The Artax will inflict guaranteed Cold status effect on enemies even if the weapon's element has been changed via elemental damage mods.
Eagle Eye will improve the detection range, making the sentinel fire farther than 30m (tested on Taxon). However, the weapon's base maximum range seems to also be 30m, causing the sentinel to fire at enemies that are out of Artax's range.
Sinister Reach improves the effective range of Artax, but Taxon will not fire farther than 30m without Eagle Eye. It is therefore advised to use both. Note that the accuracy of the weapon is fairly low at such range, and Rifle-type weapon accuracy cannot be improved. Diriga will fire it at full Calculated Shot range, even if the target is out of Artax range. (Requires further testing)
It is highly advised to use a Punch Through mod, as the weapon performs poorly against enemies behind cover. Punch Through also increases the chance of freezing several enemies at close range while moving around them.
Continuous Misery increases the duration of the visual cold effect, but not the actual slow effect.
As of Hotfix 19.10.1 Artax Riven Mods are no longer obtainable from Sorties. Between the introduction and the removal were only 5 days and therefore the chance of getting an Artax Riven within this period was very tiny. Hence the amount of Artax Rivens in the game is now extremely limited.
The Artax is possibly named after a horse from the children's fantasy novel The Neverending Story, which Atreyu tried to save from drowning in the Swamp of Sadness. It could also just be a portmanteau of "Arctic" and "Taxon."