The Local Volume HI Survey

ESO 149-G003 (HIPASS J2352-52) is a Magellanic barred irregular galaxy at a TF distance of 5.9 Mpc. It is seen close to edge-on and has a remarkable low-surface brightness (LSB) extension, possibly due to accretion of a dwarf companion. ESO 149-G003 is relatively isolated and lies in the southern outskirts of the Sculptor Group. Ryan-Weber et al. (2004) detect filamentary Hα emission in its bright stellar disc. Furthermore they find an isolated HII region ~1.5 arcmin to the west, which might be associated with ESO 149-G003. Close inspection of the optical images shows some flaring of the outer LSB component and potentially a very small companion (PGC 441599) to the south-east. The latter lies within the HI envelope. Our ATCA HI moment maps show a slight asymmetry of ESO 149-G003's HI distribution, which is further emphasized by its unusual two-component velocity field. The peculiar HI emission towards the northern (receding) end of the galaxy, which shows a velocity gradient nearly 90 degr different from the rotating disc, is offset from the very faint stellar extension. We suggest that ESO 149-G003 may have undergone a minor merger event, the debris of which are detected in the form of HI tidal tails and extended stellar streams. Wang et al. (2016) find the galaxy to lie offset from the D_HI − M_HI relation, which is not surprising given the extended peculiar emission. We measure FHI = 7.2 Jy km/s, in agreement with HIPASS (Koribalski et al. 2004), and derive an HI mass of 5.9 × 10⁷ M_☉.

Reference: Koribalski et al. 2018 * LVHIS database * LVHIS homepage * next