Dust in elliptical galaxies: a new dust mass evaluation

In order to investigate the nature and origin of dust in elliptical galaxies, a method for the dust mass evaluation, which accounts for the dust temperature distribution, is here presented and discussed. The derived dust masses turn out to be a factor 2-6 larger than those obtained with the single temperature approximation. A correlation between the far-infrared and the blue luminosity has been also found. The results are discussed in terms of dust "mass discrepancy" and of the possible evolution scenarios: evaporation flow and/or cooling flow. While the present data cannot discriminate between these two scenarios, it is conceivable that the dust in elliptical galaxies can be accreted by the contribution of different mechanisms, according to the history of the individual objects.