CCD photometry of axisymmetric and non-axisymmetric Galactic bulges in the I-band

Varela, A. M.; Munoz-Tunon, C.; Beckman, J. E.; Prieto, M.; Cepa, J.
Bibliographical reference

IN: ESO/CTIO Workshop on Bulges of Galaxies, La Serena, Chile, Jan. 16-19, 1990, Proceedings (A92-18101 05-90). Garching, Federal Republic of Germany, European Southern Observatory, 1990, p. 285-288.

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The paper presents a set of CCD images of four Galactic bulges, taken in the I photometric band under very good imaging conditions, with the Taurus camera on the 4.2-m William Herschel Telescope. As well as showing calibrated isophotes, the results of ellipticity analysis are given, which bring out a clear dichotomy between two of the bulges, where a degree of triaxiality is implied, and the other two, which are much closer to axisymmetry. In the nonaxisymmetric cases, ellipticities and position angles vary rapidly with radius within the bulge. The presence of star-forming activity can be inferred, which is probably induced by an effect of the underlying asymmetry in the older stellar population.