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Session 51 - Interstellar Medium II.
Display session, Thursday, January 08
As part of a program to characterize 1øver4 keV fluctuations at high galactic latitudes, such as those discovered by Barber, Warwick, amp; Snowden (1995), it is necessary to characterize the fluctuations produced by the principal foreground components of the 1øver4 keV background, the Local Hot Bubble. To do so, we are studying a substantial number of deep, overlapping ROSAT PSPC pointings towards the Hyades cluster, a region which has a substantial absorbing column outside the LHB that effectively blocks the distant 1øver4 keV emission. Absorption of X-ray emission by clouds within the LHB is thought to be small in this direction and can be determined by modeling the ROSAT response function. The structure of the X-ray emission in this field can be caused by 1.) changes in the pathlength to the LHB boundary, and 2.) variation in emission measure within the LHB. The amplitude of fluctuations can then place limits on these quantities, but cannot separate their effects.
Program listing for Thursday