We present H i 21 cm line observations , obtained with the Australia Telescope Compact Array , of two dwarf elliptical galaxies ( dEs ) in the Fornax cluster : FCC032 and FCC336 .
The optical positions and velocities of these galaxies place them well within the Fornax cluster .
FCC032 was detected at the 3 \sigma significance level with a total H i flux density of 0.66 \pm 0.22 Jy km s ^ { -1 } or an H i mass of 5.0 \pm 1.7 \times 10 ^ { 7 } h _ { 75 } ^ { -2 } M _ { \odot } .
Based on our deep H \alpha + [ { N { \sc ii } } ] narrow-band images , obtained with FORS2 mounted on the VLT , this dE was already known to contain 600-1800 h _ { 75 } ^ { -2 } M _ { \odot } of ionised Hydrogen ( depending on the relative strengths of the H \alpha and [ N ii ] emission lines ) .
Hence , this is the first study of the complex , multi-phase interstellar medium of a dE outside the Local Group .
FCC336 was detected at the same significance level : 0.37 \pm 0.10 Jy km s ^ { -1 } or a total H i mass of 2.8 \pm 0.7 \times 10 ^ { 7 } h _ { 75 } ^ { -2 } M _ { \odot } .
Using a compilation of H i data of dwarf galaxies , we find that the observed high H i -mass boundary of the distribution of dIrrs , BCDs , and dEs in a \log ( L _ { B } ) versus \log ( M _ { H { \sc i } } ) diagram is in good agreement with a simple chemical evolution model with continuous star formation .
The existence of many gas-poor dEs ( undetected at 21 cm ) suggest that the environment ( or more particularly , a galaxy ’ s orbit within a cluster ) also plays a crucial role in determining the amount of gas in present-day dEs .
E.g. , FCC032 and FCC336 are located in the sparsely populated outskirts of the Fornax cluster .
This is in agreement with H i surveys of dEs in the Virgo Cluster and an H \alpha survey of the Fornax Cluster , which also tend to place gas-rich dwarf galaxies in the cluster periphery .