Near-Infrared Imaging of Radio-Luminous Starburst Galaxies

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Session 31 -- Star-Forming Galaxies
Display presentation, Tuesday, 9:30-6:30, Heller Lounge Room

[31.18] Near-Infrared Imaging of Radio-Luminous Starburst Galaxies

D.A. Smith, T.L. Herter, M.P. Haynes (Cornell U.)

The infrared bright ``starburst'' galaxies discovered by IRAS define a class of objects characterized by a large population of hot young stars, unusually high star formation rates and significant dust obscuration. The mechanism responsible for triggering this rapid star formation and the resulting stellar mass distribution are currently not well understood. This project uses near-infrared imaging, near-infrared and optical spectroscopy and numerical modeling to determine the underlying galaxy morphology, dynamical mass, starburst age, star-formation rate and supergiant population for a sample of nearby radio-luminous starburst galaxies. We can then use these properties to infer the stellar mass distribution and star-formation history in starburst systems.

We have obtained deep 1.25, 1.65 and 2.2 ${\rm \mu m}$ (J, H and K band) images of 19 of these starburst galaxies and 2 normal comparison galaxies. The K band images trace the spatial distribution of the underlying stellar population. A comparison of J-H and H-K color maps constructed from the J, H and K images provide extinction and thermal dust emission estimates. We present the K band images, along with results from our J-H and H-K color maps. We find that the near-infrared colors for these galaxies can often be explained in terms of a giant or supergiant stellar population reddened by extinction and dust emission.

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