The Local Volume HI Survey

ESO 215-G?009 (HIPASS J1057-48) is a highly obscured (b = 10.5 degr) dwarf irregular galaxy at a TRGB distance of 5.25 ± 0.41 Mpc (Karachentsev et al. 2007). It appears to be rather isolated with a low current star formation rate. Its nearest known neighbour is likely the small spiral galaxy ESO 318-G013 (HIPASS J1047-38) nearly 10 degrees away. Warren, Jerjen & Koribalski (2004) determine an HI mass to light ratio of M_HI/L_B = 22 ± 4 M_☉/L_☉, the highest recorded for a galaxy in the literature. Our ATCA data show the HI disc of ESO 215-G?009 to extend over six times the Holmberg radius of the stellar disc. We measure F_HI = 110.1 Jy km/s, in agreement with HIPASS (Koribalski et al. 2004), and derive M_HI = 7.1 × 10⁸ M_☉. Warren et al. (2004) note that its azimuthally averaged surface density remains below the critical gas surface density at all radii. While its rotation pattern is very regular, the galaxy's near circular shape (suggesting a near face-on orientation if the gas rotates in circular orbits) is somewhat in contrast to the measured rotation amplitude. Using 3D FAT Kamphuis et al. (2015) obtain an HI rotation curve indicating v_rot = 93.0 km/s at R_max = 9.3 kpc (for i = 18.5 degr and PA = 119.7 degr) and M_dyn = 1.9 × 10¹⁰ M_☉. See also previous HI kinematics analysis by Warren et al. (2004) and Kirby et al. (2012).

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