Context :

Aims : To compute the chemical evolution of spiral bulges hosting Seyfert nuclei , based on updated chemical and spectro-photometrical evolution models for the bulge of our Galaxy , to make predictions about other quantities measured in Seyferts , and to model the photometric features of local bulges .
The chemical evolution model contains updated and detailed calculations of the Galactic potential and of the feedback from the central supermassive black hole , and the spectro-photometric model covers a wide range of stellar ages and metallicities .

Methods : We computed the evolution of bulges in the mass range 2 \times 10 ^ { 9 } -10 ^ { 11 } M _ { \odot } by scaling the efficiency of star formation and the bulge scalelength as in the inverse-wind scenario for elliptical galaxies , and considering an Eddington limited accretion onto the central supermassive black hole .

Results : We successfully reproduced the observed relation between the mass of the black hole and that of the host bulge .
The observed nuclear bolometric luminosity emitted by the supermassive black hole is reproduced only at high redshift or for the most massive bulges ; in the other cases , at z \simeq 0 a rejuvenation mechanism is necessary .
The energy provided by the black hole is in most cases not significant in the triggering of the galactic wind .
The observed high star formation rates and metal overabundances are easily achieved , as well as the constancy of chemical abundances with the redshift and the bulge present-day colours .
Those results are not affected if we vary the index of the stellar IMF from x = 0.95 to x = 1.35 ; a steeper IMF is instead required in order to reproduce the colour-magnitude relation and the present K -band luminosity of the bulge .

Conclusions : We show that the chemical evolution of the host bulge , with a short formation timescale of \sim 0.1 Gyr , a rather high efficiency of star formation ranging from 11 to 50 Gyr ^ { -1 } according to the bulge mass and an IMF flatter with respect to the solar neighbourhood , combined with the accretion onto the black hole is sufficient to explain the main observed features of Seyfert galaxies .