Just a few more notes on the continuum, particularly the feature around 2200A.
It seems that we never see this in 'emission'. If we see it at all, it is in
'absorption'. I suppose the standard explanation for this is that the feature
does not appear in the scattering albedo of the larger grains which do most of
the reflection. Rather, it appears as an absorption in the small carbon grains
which do not contribute much to the scattering. This is discussed in Manzini
and di Serego...

The plots which I referenced in yesterday's note, #1, were just made by
extinction of an input power law - so the feature has to be in absorption. It
is instructive to look at an alternative plot which is generated by scattering
flux from a region where the extinction and scattering cross sections are
identical (a pure scatterer). If we do this using a standard Galactic
extinction law, we get a family of curves as a function of E_B-V - shown in:
http://ecf.hq.eso.org/~rfosbury/research/z2p5/TXS0211_temt.gif
where you can see how the feature goes from emission to absorption as we go
through the maximum emergent scattered flux. It is possible to get just as good
a fit using this model, although the required optical depth is larger.

Clearly, we need to model this using the Manzini and di Serego formalism - but
the simple models are instructive.

By the way, I compared our MRC0943 spectrum with Pat McCarthy's photometric
data from the ground, from WFPC2 and from NICMOS. You can see the result in:
http://ecf.hq.eso.org/~rfosbury/research/z2p5/MRC0943_SED.gif
where you can ignore the green and yellow points (an attempt to separate the
galaxy from the extended components). Pat's data were from a 4" aperture which
probably explains our somewhat lower fluxes (although some of his bands include
emission lines). A crude colour image - from the WFPC2 and NICMOS data is shown
in:
http://ecf.hq.eso.org/~rfosbury/research/z2p5/0942-242_col.gif

All for now...
Have a good weekend!
Bob...