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   PR # 41252
   We propose a new method to derive the Hubble constant by making use
   of intensity decrement of Fe-K lines at the central core region
   caused by a resonant scattering effect in an intracluster medium. Two
   clusters A576(z=0.0381) and A1650(z=0.0845) are selected for this
   purpose under the conditions of high intensity, temperature,
   abundance and luminosity and large angular size fit well to GIS field
   of view. The finite optical depth of Fe-K lines is essential to
   derive the total amount of gas and result in obtaining the absolute
   cluster size. The data analysis of PV and AO3 clusters indicates the
   usefulness of this method.
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