AM-1 - A very distant globular cluster

Abstract

view Abstract Citations (38) References (44) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS AM-1 : a very distant globular cluster. Aaronson, M. ; Schommer, R. A. ; Olszewski, E. W. Abstract Deep B and V frames have been obtained for Arp-Madore 1 (AM-1) using the Cerro Tololo 4 m telescope and prime focus CCD camera, confirming the nature of this object as a globular cluster. In particular, the resulting color-magnitude diagram shows a sharply defined red horizontal branch at apparent magnitude m(V) = 20.93 + or - 0.04. Adopting M(V)(HB) = 0.6 then yields a galactocentric distance of 118 kpc, an amount placing AM-1 as the most distant globular cluster yet identified which may still be associated with the Galaxy. From the color of the giant branch at the horizontal branch, Fe/H is estimated as -1.8 + or - 0.3, a value which lends support to previous arguments that the abundance gradient in the outer halo is weak. In stellar content AM-1 appears similar to the other low-luminosity members of the outer halo - the Palomar clusters and dwarf spheroidals. Publication: The Astrophysical Journal Pub Date: January 1984 DOI: 10.1086/161605 Bibcode: 1984ApJ...276..221A Keywords: Abundance; Globular Clusters; Stellar Spectrophotometry; Color-Magnitude Diagram; Halos; Hertzsprung-Russell Diagram; Horizontal Branch Stars; Stellar Color; Stellar Luminosity; Stellar Magnitude; Astrophysics full text sources ADS | data products SIMBAD (5)