The Local Volume HI Survey (LVHIS)


ESO 154-G023 (HIPASS J0256-54) is a Magellanic barred spiral galaxy at a TRGB distance of 5.76 ± 0.10 Mpc (Tully et al. 2006). Its closest neighbour is NGC 1311 (DTRGB = 5.20 Mpc), more than 4 degrees away. ESO 154-G023 is similar to the galaxy ESO 115-G021 in size and orientation (Koribalski 2008). When comparing the optical discs, ESO 154-G023 appears to have either a thicker disc or is slightly less inclined than ESO 115-G021. Our ATCA HI maps show an extended, regularly rotating HI disc with a pronounced warp on both sides. The latter appears to start at the edge of the bright stellar disc and is likely contributing to the apparent disc thickness. We measure ATCA FHI = 130.6 Jy km/s, within the ~10% uncertainty of the HIPASS FHI (Koribalski et al. 2004), and derive MHI = 109 M. Using 3D FAT Kamphuis et al. (2015) obtain an HI rotation curve indicating vrot = 63.6 km/s at Rmax = 15.7 kpc (for i = 79.7 degr and PA = 218.3 degr) and Mdyn = 1.5 × 1010 M. SINGG Hα images reveal star formation throughout the stellar disc (Meurer et al. 2006).

Furthermore, our deep ATCA HI observations reveal a dwarf galaxy at α,δ(J2000) = 02:56:40.3, -54:35:38.8 behind the disc of ESO 154-G023 at velocities of ~1100 to 1140 km/s. We measure FHI = 0.31 Jy km/s and derive MHI = 1.2 × 107 M for D = 12.7 Mpc. The newly discovered galaxy is also detected in the AAT H-band (see Kirby et al. 2008), SINGG Hα (Meurer et al. 2006) and GALEX UV images.

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

Last updated on 18 Feb 2018. © Copyright CSIRO