The real question them becomes: what does "the point of origin" mean in this description. In other words, is that point or origin fixed or can it move. Looking at other spells with emanations, it's pretty clear that it can move.PF SRD wrote:Burst, Emanation, or Spread
Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell's point of origin and measure its effect from that point.
A burst spell affects whatever it catches in its area, including creatures that you can't see. It can't affect creatures with total cover from its point of origin (in other words, its effects don't extend around corners). The default shape for a burst effect is a sphere, but some burst spells are specifically described as cone-shaped. a burst's area defines how far from the point of origin the spell's effect extends.
An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell. Most emanations are cones or spheres.
A spread spell extends out like a burst but can turn corners. You select the point of origin, and the spell spreads out a given distance in all directions. Figure the area the spell effect fills by taking into account any turns the spell effect takes.
Discovery Torch is a spell with a 40' emanation that creates a torch of light that by implication can be moved.
Circle of Clarity is a spell that is specifically noted to be stationary if cast on a point in space. It is mobile if centered on a creature or object, implying that emanations can move.
Alter Winds specifically notes that it is a "stationary emanation". By standard rules of statutory interpretation, the word "stationary" must be given some meaning. If all emanations are stationary, then it would be superfluous. Therefore, all emanations cannot be stationary.
Based on all that, my best interpretation (which is only my opinion, mind you) is that the Detect Magic conical emanation should move with the caster.