FCC 35 and Its HI Companion: Multiwavelength Observations and Interpretation

Putman, M.E., Bureau, M., Mould, J.R., Staveley-Smith, L., Freeman, K.C.

(1998) AJ 115, 2345

Abstract. The Fornax Cluster galaxy FCC 35 shows an unusual multiply peaked integrated HI profile. We have now observed FCC 35 with the Australia Telescope Compact Array and have found a compact HI source with M_HI = 2.2 x 10^8 Msun; and a spatially overlapping complex of HI gas with the same mass. By combining optical observations with the HI data, we are able to identify FCC 35 as a young compact source of star formation with a nearby intergalactic HI cloud that is devoid of stars. We classify FCC 35 as a blue compact dwarf or HII galaxy, having large amounts of neutral hydrogen, very blue colors (U - V = 0.1), and a low-metallicity spectrum with strong narrow emission lines. Together with the presence of the HI cloud, this suggests that FCC 35 is the result of a recent interaction within the Fornax Cluster.

HI distribution of the galaxy FCC 35 overlaid onto an optical image from the DSS

HI distribution of the cloud near FCC 35 overlaid onto an optical image from the DSS

Baerbel.Koribalski @ csiro.au