Nuclear Star Formation in the Hotspot Galaxy NGC 2903

Alonso-Herrero, A.; Ryder, S. D.; Knapen, J. H.
Bibliographical reference

The Central Kiloparsec of Starbursts and AGN: The La Palma Connection, ASP Conference Proceedings Vol. 249. Edited by J. H. Knapen, J. E. Beckman, I. Shlosman, and T. J. Mahoney. ISBN: 1-58381-089-7. San Francisco: Astronomical Society of the Pacific, 2001, p. 557.

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2001
Number of authors
3
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0
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0
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0
Description
We analyze the star formation properties of the hotspot galaxy NGC 2903 using high resolution Hubble Space Telescope and adaptive optics observations. The circumnuclear star formation in NGC 2903 shows a ringlike morphology with an approximate diameter of 625 pc. For the first time, the infrared hotspots have been resolved into individual young stellar clusters or groups of these. We constrain the ages of the stellar clusters to 4--7 Myr after the peak of star formation, or to absolute ages of 6.5--9.5 Myr for the assumed short-duration Gaussian bursts, by using the available photometric and spectroscopic data, together with evolutionary synthesis models. The H ii regions in the circumnuclear star-forming ring have Paα luminosities close to that of the giant H ii region 30 Doradus. Their spatial distribution is not coincident with that of the stellar clusters, which are older than the H ii regions. We postulate that the H ii regions will evolve into bright infrared stellar clusters similar to those observed today.