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An extended multi-zone model for the MCG-6-30-15 warm absorber
The variable warm absorber seen with {\em ASCA} in the X-ray spectrum of
MCG6-30-15 shows complex time behaviour in which the optical depth of OVIII
anticorrelates with the flux whereas that of OVII is unchanging. The
explanation in terms of a two zone absorber has since been challenged by {\em
BeppoSAX} observations. These present a more complicated behaviour for the
OVIII edge. We demonstrate here that the presence of a third, intermediate,
zone can explain all the observations. In practice, warm absorbers are likely
to be extended, multi-zone regions of which only part causes directly
observable absorption edges at any given time.Comment: 5 pages, 6 figures, accepted for publication in MNRA
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