Burton's Curse: The Impact of Bulk Flows on the Galactic
  Longitude-Velocity Diagram and the Illusion of a Continuous Perseus Arm
  In this work we demonstrate that the Perseus Arm is not a continuous
structure of molecular gas in the second quadrant. We first show that the
observed, distanced-resolved velocity structure of the Galaxy in the outer disk
is capable of creating illusory spiral arms, as was first proposed by Burton
(1971). Second, we measure the distances to a collection of CO clouds at
velocities consistent with the Perseus arm with $135^\circ < l < 160^\circ$. We
find these distances using 3D dust maps from Green et al. (2019). We determine
that these molecular cloud do not preferentially lie at the distance of a
purported Perseus arm, but rather extend over 3 kpc in distance, with some
evidence for a closer, high pitch angle structure between 1 and 1.5 kpc away.
Finally, we demonstrate that velocity perturbations of the amplitude found near
the Perseus arm can wreak havoc on our interpretation of the longitude-velocity
diagram for more than half of the Milky Way disk.
