  This is a companion paper of arXiv:1601.03586. We study Coulomb branches of
unframed and framed quiver gauge theories of type $ADE$. In the unframed case
they are isomorphic to the moduli space of based rational maps from ${\mathbb
C}P^1$ to the flag variety. In the framed case they are slices in the affine
Grassmannian and their generalization. In the appendix, written jointly with
Joel Kamnitzer, Ryosuke Kodera, Ben Webster, and Alex Weekes, we identify the
quantized Coulomb branch with the truncated shifted Yangian.
