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| Paper: |
Luminosity Profiles of Merger Remnants |
| Volume: |
197, XVth IAP Meeting Dynamics of Galaxies: From the Early Universe to the Present |
| Page: |
349 |
| Authors: |
Hibbard, J. E.; Yun, Min. S. |
| Abstract: |
Hydrodynamical simulations of gas-rich mergers predict that huge concentrations of gas will accumulate within the central regions of the merger remnants. Should this material be converted into stars, the resulting remnant luminosity profiles will be unlike those seen in normal ellipticals (Mihos & Hernquist 1994), exhibiting a luminosity ``spike'' at small radii. We investigate this prediction observationally using three on-going or late-stage mergers for which high-resolution molecular and optical or near infrared surface brightness profiles are available from the literature. For each system, the observed gas column density is converted into an optical surface brightness by assuming a stellar mass-to-light ratio appropriate for an evolved population. For NGC 3921 and NGC 7252 we predict that the resulting luminosity profiles will be characterized by an r1/4 law. In view of previous optical work on these systems, it seems likely that they will evolve into normal ellipticals as regards their optical properties. Due to a much higher central molecular column density, Arp 220 might not evolve such a ``seamless'' light profile. We conclude that ultraluminous infrared mergers such as Arp 220 either evolve into ellipticals with anomalous luminosity profiles, or do not produce many low-mass stars out of their central molecular gas complexes. |
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