The generalized hardness-intensity diagram for black hole and neutron
  star X-ray binaries
  Over the past half century, X-ray and radio observations of accreting neutron
stars and stellar mass black holes have yielded a rich observational picture
with common features including state transitions and jet formation, but also
sharp differences. While black hole X-ray binaries overwhelmingly suppress jets
in so-called soft states, accreting neutron stars are less restrictive, with a
soft state wind observed in some sources to co-exist with a jet. We propose an
explanation for these differences that leads to a generalization of a
foundational element, the hardness-intensity diagram of Fender et al (2004).
The inverse relation between jets and winds fits into a picture that connects
to prograde accretion while the possibility of counterrotation between
accretion disk and compact object accounts for observed differences in
accreting neutron stars. This picture comes with a surprising twist, which is
that neutron stars embody the small-scale analog of FRII quasars, an idea that
allows us to complete the scale invariant picture for the jet-disk connection.
