2005/10/09 by M. Mouhcine, H. C. Ferguson, R. M. Rich +2 · 69 citations
Engineering · Physics and Astronomy · #Astronomy and Astrophysical Research #Cepheid variable #Distance modulus #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Hubble sequence #Large Magellanic Cloud #Population #Red clump #Red-giant branch #Space Technology and Applications #Spiral galaxy #astro-ph
paper · pdf · doi:10.1086/468177
published in The Astrophysical Journal 633(2), 810-820 (IOP Publishing) · 12 pages, 6 figures
arxiv created 2005/10/09 · openalex publication_date 2005/11/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We have imaged the halo populations of a sample of nearby spiral galaxies using the Wide Field Planetary Camera 2 on board the Hubble Space Telescope with the aim of studying the stellar population properties and relating them to those of the host galaxies. In four galaxies, the red giant branch is sufficiently well populated to measure the magnitude of the tip of the red giant branch (TRGB), a well-known distance indicator. Using both the Sobel edge-detection technique and maximum likelihood analysis to measure the I -band magnitude of the TRGB, we determine distances to four nearby galaxies: NGC 253, NGC 4244, NGC 4945, and NGC 4258. For the first three galaxies, the TRGB distance is here determined more directly, and is likely to be more accurate, than previous distance estimates. In the case of NGC 4258, our TRGB distance is in good agreement with the geometrical maser distance, supporting the Large Magellanic Cloud distance modulus ( m - M ) 0 = 18.50 that is generally adopted in recent estimates of the Hubble constant.