Cosmic X-ray Background

• Total Cosmic X-ray background (0.5 - 2 keV):

• ~ 6. - 8. 10-12 ergs cm-2 s-1 deg-2

• Contribution from discrete sources:

• 74 - 94 % (Mushotzky et al. 2000)

• Contribution from WHIM:

• likely ~ 5% (simulations from Croft et al. 2000, Phillips et al. 2001)

• Metal line emission account for a significant portion of WHIM emission!