Polars: X-ray emission
€Polars/AM
Her stars were found to be strong soft X-ray emitters (~1033 erg/s) in early surveys
€X-ray
emission characterised by thermalised free-fall velocities from a
white dwarf so emission was from a hot region close to
the white dwarf surface: post-shock
€Cyclotron
emission must also be from a hot region (otherwise narrow cyclotron
emission lines rather than continuum)
AM
Her
Rothschild et al (1981)