observational overview of state transitions in x-ray binaries

STATE CLASSIFICATION
• Various classification schemes, using (broadband) spectral and
variability information
• McClintock & Remillard 2005 (focused on three ‘stable’
states)
• Homan & Belloni 2005 (focused on transitions)
• Future schemes may use X-ray line spectra, multi-wavelength
information, etc.
Okay, let’s move on to the states. As I said before, states are typically defined as distinct
combinations of X-ray spectral and variability properties, and, as I said earlier we believe that
these states reflect different modes of accretion.
Through the years various state classification schemes have been proposed, but the two most
commonly used ones are the ones by McClintock and Remillard, which put more emphasis on
the ‘stable’ states, and the one by myself and Tomaso Belloni, which puts more emphasis on
the transitions between states. To a large extend these schemes are consistent though, and I
will use definitions from both schemes
With the wealth of multi-wavelength data becoming available, future schemes might actually
include more than X-ray spectra and variability alone.