2005A&A...443..373S

The LGG 138 galaxy group members NGC2292 and NGC2293 were imaged with ISOPHOT in the far-infrared (FIR) at 60µm, 100µm, and 200µm. While no FIR emission is seen at 60µm, and only very low level emission is present at 100µm, compact FIR emission from both NGC2292 and NGC2293 galaxy centres and extended emission likely associated with tidally removed dust and the HI ring surrounding NGC2292/2293 is strongly detected at 200µm. Additionally, a compact FIR source associated with the neighbouring galaxy NGC2295 is strongly detected at 200µm. Remarkably, none of these three galaxies have been detected individually in 21cm HI emission. The steeply rising far-infrared spectral energy distribution of the apparently interacting NGC2292/2293 pair towards longer wavelengths indicates the thermal emission of very cold dust with a temperature of 13K, much lower than typical values of interacting systems or even quiescent spiral galaxies. The FIR data of this galaxy group clearly shows for the first time that there could be FIR dust emission not accompanied by HI, that dust even in an interacting system can have a very low dust temperature, and furthermore that gravitational interaction can give rise to an extended diffuse dust distribution.