HI associated with the Centaurus Group dSph CEN_41

Recently Beaulieu et al. (1998) have started to look for HI in dSph-like systems associated with the Sculptor and Centaurus Groups. So far two out of four objects observed were detected, namely the dS0 NGC 59 in the Sculptor Group and the dSph CEN_41 (Fig. 4) in the Centaurus Group. Contrary to what is seen for the LG dSph Sculptor, the HI is well centred on the optical in both cases, which means that we should expect to find relatively young stellar populations in those systems.

Figure 4: HI surface densities of CEN_41, superposed on an STScI Digitized Sky Survey optical image, for a single field ATCA observation. The contours are 0.5, 1.0, 1.5, 2.0, 2.5 & 3.0

x 10¹⁹ cm^-2.

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