Probing the 4U 1624-490 Ionized Gas and Dust distribution along the LOS
Jinge Xiang (Harvard University) , Julia C. Lee (Harvard University), Michael A. Nowak, Norbert S. Schulz (MIT)
We present results based on our 76 ks Chandra HETGS observation of the "Big Dipper" 4U 1624-490. Specifically, we discuss how the detected Fe line absorption evolves with orbital phase during persistent phases in the context of the geometry of the system as well as changes in plasma conditions over the 4U 1624-490 binary orbit. We show that the evolution of these lines can be modeled using the ``XSTAR'' photoionized code which places the location of "hot" (
K) gas in a region where an Accretion Disk Corona (ADC) is expected to exist an the location of "warm" (
K) gas in a region between the ADC and the disk edge. In addition, we will show how we have used the associated dust scattering halo to derive a geometric distance of 15 kpc to this binary, as well as assess location, uniformity and density of ISM dust grains along the line of sight to this source.