NOAO >   Observing Info >   Approved Programs >   2001A-0107

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Proposal Information for 2001A-0107


PI: Henrique R. Schmitt, National Radio Astronomy Observatory, schmitt@stsci.edu
Address: P.O. Box 0, Socorro, NM 87801, USA

CoI: Roberto Cid Fernandes, Johns Hopkins University
CoI: Timothy M. Heckman, Johns Hopkins University
CoI: Claus Leitherer, Space Telescope Science Institute
CoI: Thaisa Storchi-Bergmann, Instituto de Fisica - UFRGS
CoI: Rosa Gonzalez Delgado, Instituto Astrofisico de Andalucia

Title: The Nature of LINER's

Abstract: LINER's (Low Ionization Nuclear Emission-line Regions) are nearly ubiquitous in the nuclei of early-type galaxies, and are the prime candidates for low-level activity associated with dormant supermassive black holes. However, their energy source is still controversial. While photoionization by a low-power AGN is viable, an important contribution by young stars in a weak nuclear starburst can not be excluded in most cases. Here we propose a \it direct test of the starburst model by searching for the direct signature of young stars in the blue/near-UV spectral region (3600-4400\AA), which is the most sensitive to the presence of hot, young stars. These data will be used to study the stellar population of the nuclear region of these galaxies, to determine the age and mass of the last star formation event, and the contribution of these stars to the ionizing flux. This is a more direct and precise test for the presence of young stars than the analysis of emission line ratios in diagnostic diagrams used in most of the previous work on the subject.


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NOAO >   Observing Info >   Approved Programs >   2001A-0107

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