X-rays result from accretion phenomena in general
Many black hole candidates in contrast to radio pulsars
Again classified on the basis on companion mass
Most high mass systems are X-rays pulsars
Only 3 low mass systems are X-ray pulsars!
Generally shorter life times than MSPs
Easier to detect
Virtually all lmxbs and hmxbs have been found
Many evolutionary links to radio pulsars
few seconds < P < few hundred seconds
Phases of spin-up and spin-down
