  Two recent works have analyzed a solar large and steady coronal loop observed
with Yohkoh/SXT in two filter passbands to infer the distribution of the
heating along it. Priest et al. (2000) modelled the distribution of the
temperature obtained from filter ratio method with an analytical approach, and
concluded that the heating was uniform along the loop. Aschwanden (2001) found
that a uniform heating led to an unreasonably large plasma column depth along
the line of sight, and, using a two component loop model, that a
footpoint-heated model loop (with a minor cool component) yields more
acceptable physical solutions. We revisit the analysis of the same loop system,
considering conventional hydrostatic single loop models with uniformly
distributed heating, and with heating localized at the footpoints and at the
apex, and an unstructured background contribution extrapolated from the region
below the analyzed loop. The flux profiles synthesized from the loop models
have been compared in detail with those observed in both filter passbands with
and without background subtraction; we find that background-subtracted data are
fitted with acceptable statistical significance by a model of relatively hot
loop (~3.7 MK) heated at the apex, with a column depth ~1/10 of the loop
length. In discussing our results, we put warnings on the importance of aspects
of data analysis and modeling, such as considering diffuse background emission
in complex loop regions.
