Multiwavelength study of the star-formation in the bar of NGC 2903
Metadatos
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European Southern Observatory (ESO); Springer Verlag
Materia
Galaxies Barred NGC 2903 Evolution ISM Dynamics HII regions Ultraviolet
Date
2010Referencia bibliográfica
Popping, G.; Pérez, I.; Zurita, A. Multiwavelength study of the star-formation in the bar of NGC 2903. Astronomy and Astrophysics, 521: A8 (2010). [http://hdl.handle.net/10481/28439]
Patrocinador
G. Popping acknowledges support by the Stichting Groninger Universiteitsfonds. I. Pérez acknowledges support by the Netherlands Organisation for Scientific Research (NWO, Veni-Grant 639.041.511). I. Pérez and A. Zurita acknowledge support from the Spanish Plan Nacional del Espacio de Ministerio de Educación y Ciencia (via grant C-CONSOLIDER AYA 2007-67625-C02-02). I. Pérez & A. Zurita also thank the Junta de Andalucía for support through the FQM-108 project.Résumé
Aims. NGC 2903 is a nearby barred spiral with an active starburst in the center and H ii 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. Methods. 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 Hα 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 Hα EWs, and their spatial distribution have been
analysed. Stellar cluster ages have been estimated using stellar population synthesis models (Starburst99). Results. NGC 2903 is a complex galaxy, with a very different morphology on each spectral band. The CO (J=1-0) and the 3.6 µm
emission trace each other in a clear barred structure, while the Hα 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 ∼ 2.5kpc. These regions do not
show a significant Hα nor 24 µm 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⊙ yr−1
, compatible
with the SFR as derived from Hα calibrations (∼1 M⊙ yr−1
).