1 research outputs found
Ages and metallicities of circumnuclear star formation regions from Gemini IFU observations
Aims: We derive the age and metallicity of circumnuclear star formation
regions (CNSFRs) located in the spiral galaxies NGC6951 and NGC1097, and
investigate the cause of the very low equivalent widths of emission lines found
for these regions.
Methods: We used optical two-dimensional spectroscopic data obtained with
Gemini GMOS-IFUs and a grid of photoionization models to derive the the
metallicities and ages of CNSFRs.
Results: We find star formation rates in the range 0.002-0.14 Msun/yr and
oxygen abundance of 12+log(O/H)~8.8 dex, similar to those of most metal-rich
nebulae located in the inner region of galactic disks.
Conclusions: We conclude that the very low emission-line equivalent widths
observed in CNSFRs are caused by the ``contamination'' of the continuum by (1)
contribution of the underlying bulge continuum combined with (2) contribution
from previous episodes of star formation at the CNSFRs.Comment: Accepted for publication in Astronomy and Astrophysic