Dwarf galaxies are dominated by dark matter even in the innermost regions
and, therefore, provide excellent probes for the investigation of dark halos.
To that purpose, we analyse ROSAT PSPC-data of the dwarf galaxy NGC 247. We
focus in particular on the diffuse X-ray emission in the 1/4keV band.
Assuming an isothermal density profile, we find that the mass of the hot
emitting gas is about 108M⊙​, corresponding to ≲0.5
of the total dynamical mass of the galaxy. The total mass of NGC 247, as
derived from the X-ray data agrees quite well with the value obtained from the
measured rotation curve (Burlak). The X-ray profile in the 3/4keV and 1.5keV band shows an excess at a radial distance of about 15 arcmin from the
center. Such a ``hump'' in the radial X-ray profile can be explained by the
presence of a cluster of young low mass stars or brown dwarfs. Therefore, NGC
247 offers the possibility to observe the formation of a halo of MACHOs.Comment: 6 pages, accepted for publication in A &