Astronomy and Astrophysics, volume 455, 891-896 (2006/9-1)
Distance determination to NGC 55 from the planetary nebula luminosity function.
VAN DE STEENE G.C., JACOBY G.H., PRAET C., CIARDULLO R. and DEJONGHE H.
Abstract (from CDS):
We analysed [O III], Hα, and continuum images of the Sculptor Group spiral galaxy NGC 55 obtained with the WFI instrument at the 2.2-m telescope of ESO. We identified 21 new planetary nebula candidates. We constructed the [O III]λ5007 Planetary Nebula Luminosity Function (PNLF) and determined a most likely distance of 2.30±0.35Mpc. The distance to NGC 55 is a bit larger than previously determined distances, which means that the Sculptor Group is further away from the Local Group than previously thought. The PNLF distance to NGC 55 is comparable to the PNLF distance of NGC 300 (Soffner et al., 1996A&A...306....9S), adding support to the suggestion that these galaxies form a bound pair. There doesn't seem to be a shortage of planetary nebula candidates in this metal poor galaxy.
planetary nebulae: general - galaxies: individual: NGC 55 - galaxies: distances and redshifts - galaxies: clusters: individual: Sculptor Group