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S. C. Trager (OCIW), J. Dalcanton (University of Washington), R. O. Marzke, A. McWilliam, B. J. Weiner (OCIW)
We present first results from an on-going survey of the stellar populations of the bulges and inner disks of spirals at various points along the Hubble sequence. In particular, we are investigating the hypotheses that bulges of early-type spirals are akin to (and may in fact originally have been) intermediate-luminosity ellipticals while bulges of late-type spirals are formed from dynamical instabilities in their disks (e.g. Pfenniger 1993). Absorption-line spectroscopy of the central regions of Sa--Sd spirals is combined with stellar population models (of, e.g., Worthey 1994) to determine integrated mean ages and metallicities. These ages and metallicities will be used to investigate stellar population differences both between the bulges and inner disks of these spirals and between bulges and ellipticals in an attempt to understand the formation mechanisms of spiral bulges.