Multiwavelength study of the star formation in the bar of NGC 2903
  NGC 2903 is a nearby barred spiral with an active starburst in the center and
Hii regions distributed along its bar. We aim to analyse the star formation
properties in the bar region of NGC 2903 and study the links with the typical
bar morphological features. A combination of space and ground-based data from
the far-ultraviolet to the sub-millimeter spectral ranges is used to create a
panchromatic view of the NGC 2903 bar. We produce two catalogues: one for the
current star formation regions, as traced by the halpha compact emission, and a
second one for the ultraviolet (UV) emitting knots, containing positions and
luminosities. From them we have obtained ultraviolet colours, star formation
rates, dust attenuation and halpha EWs, and their spatial distribution have
been analysed. Stellar cluster ages have been estimated using stellar
population synthesis models (Starburst99). NGC 2903 is a complex galaxy, with a
very different morphology on each spectral band. The CO(J=1-0) and the 3.6
micron emission trace each other in a clear barred structure, while the halpha
leads both components and it has an s-shape distribution. The UV emission is
patchy and does not resemble a bar. The UV emission is also characterised by a
number of regions located symmetrically with respect to the galaxy center,
almost perpendicular to the bar, in a spiral shape covering the inner ~2.5 kpc.
These regions do not show a significant halpha nor 24 micron emission. We have
estimated ages for these regions ranging from 150 to 320 Myr, being older than
the rest of the UV knots, which have ages lower than 10 Myr. The SFR calculated
from the UV emission is ~0.4 M$_{\odot}$/yr, compatible with the SFR as derived
from halpha calibrations (M$_{\odot}$/yr).
