Very Large Telescope adaptive optics images of NGC 253 with resolutions down to 200 mas resolve the central 300 pc of this galaxy in \sim 37 infrared ( IR ) bright knots , a factor of 3 larger than previously reported , and extended diffuse emission .
The angular resolution , comparable to that of available Very Large Array 2 cm maps , permits us a very accurate IR-radio registration .
Eight radio sources are found to have an IR counterpart .
The knots have H \alpha equivalent width of about 80 Å , sizes of \sim 3 pc , magnitudes in L -band of about 12 mag and relatively high extinction , A _ { V } \sim 7 mag .
Their spectral energy distributions ( SEDs ) look very similar , characterized by a maximum at 20 \micron and a gentle bump in the 1 – 2 \micron range .
These features can be well reproduced by considering an important contribution of very young stellar objects to the IR , efficiently heating their dust envelope .
The evidence indicates that these are young massive clusters bursting from their dust cocoons .
A median SED of the knots is provided , which may represent one of the most genuine templates of an extragalactic circumnuclear star-forming region .
The lack of any optical or IR counterpart for the previously identified radio core calls into question its supposed active nucleus nature .
This source may instead represent a scaled up version of Sgr A ^ { * } at the Galactic Centre .