Description
We use HST ACS and NICMOS imaging to study the inner B-I and I-H colors of nine late-type spiral galaxies, which we interpret on the basis of different star formation histories. The colors and scale lengths of the bulges of these late-type systems are correlated with those of the disks in which they are embedded. We find that in about half of the systems, the bulk of the bulge mass formed more recently than the disk. In the remainder, early bulge formation was supplemented by continuing "rejuvenating" star formation. More massive bulges are generally older.
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