  We study a type of an Unruh-DeWitt-like detector based on a vector rather
than scalar field. This detector has two energy states and produces Larmor
radiation when there is no energy gap between them. This setup indicates that
Larmor radiation and Unruh radiation are two counterparts of the same
phenomenon. Larmor radiation is observed in the inertial frame, while Unruh
radiation is observed in an accelerated frame. The accelerated observer sees
that his detector absorbed a particle inside its own accelerated horizon, while
the Larmor radiation is the companion particle which leaves the accelerated
observer's horizon. Since the detection is based on the electromagnetic field,
this type of detector is much closer to the real world than a standard
Unruh-DeWitt detector which is coupled to a scalar field.
