Star Formation in the Circumnuclear Environment of NGC1068

Richard I. Davies; Hajime Sugai; Martin J. Ward

doi:10.1046/j.1365-8711.1998.01928.x

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arXiv · astro-ph/9806345

Star Formation in the Circumnuclear Environment of NGC1068

Richard I. Davies·Hajime Sugai·Martin J. Ward

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Abstract

We present near-infrared emission line images of the circumnuclear ring in NGC1068. We have measured the Br_gamma fluxes in a number of star forming complexes and derived extinctions for each of these by comparison with H_alpha. We investigate the star forming histories of these regions and find that a short burst of star formation occured co-evally throughout the ring within the last 30-40 Myr, and perhaps as recently as 4-7 Myr ago. The 1-0 S(1) flux and S(1)/Br_gamma ratios indicate that as well as fluorescence, shock excited H_2 emission contributes to the total flux. There is excess H_2 flux to the North-West where the ionisation cone crosses the ring, and we have shown it is possible that the non-stellar continuum from the Seyfert nucleus which produces the high excitation lines could also be causing fluorescence at the edges of molecular clouds in the ring. The nuclear 1-0 S(1) is more extended than previously realised but only along the bar's major axis, and we consider mechanisms for its excitation.

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Richard I. Davies, Hajime Sugai, Martin J. Ward. 1998-06-25. Star Formation in the Circumnuclear Environment of NGC1068. https://doi.org/10.1046/j.1365-8711.1998.01928.x

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