B = 3x10 13 G
Teff = 75 eV
Left : T=cost
Right : T(q)
Spectrum
of a bare NS
after crossing a pure H
layer with rin=2x10-3 g/cm3
X-rays
will cross the layer unhindered, but the low-energy photons
get reprocessed and re-emitted as a blackbody at Tgas
The X-ray emission from the bare star is depressed by a factor ~3-4 with respect to the bb
then
the optical emission ³appears² enhanced