2-DIMENSIONAL DECOMPOSITION OF BULGE AND DISK

We describe a method of bulge-to-disk decomposition which utilizes a f ull two-dimensional image of a galaxy. It provides much better estimat es of the structural parameters for each component than the widely use d conventional procedure which involves a chi(2) decomposition on elli ptically averaged profiles. The performances of the conventional one-d imensional method and the present two-dimensional technique are compar ed by using a set of realistic model galaxy images. We show that the c onventional one-dimensional decomposition procedure is subject to stro ng systematic errors associated with the derivation of the ellipticall y averaged radial surface brightness profiles; these errors come from the different intrinsic shapes of disk and bulge, combined with the ef fects of viewing inclination. The present two-dimensional approach suc cessfully recovers the intrinsic parameters for a wide range of B/D ra tios at all inclinations.