Evidence for an old Galactic bulge from RR Lyrae stars in Baade's window - Implications for the formation of the Galaxy and the age of the universe

Abstract

view Abstract Citations (111) References (70) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evidence for an Old Galactic Bulge From RR Lyrae Stars in Baade's Window: Implications for the Formation of the Galaxy and the Age of the Universe Lee, Young-Wook Abstract Recent abundance measurements of RR Lyrae variables in the Baade's window field of the Galactic nuclear bulge are examined, and the observed metallicity distributions of the RR Lyraes in different Galactic radial zones are compared with those predicted for the HB population models. It is shown that the observed systematic variation with Galactocentric distance is only explained if the age of the stellar population increases, in the mean, with decreasing R(G). Thus, the oldest stellar population, the RR Lyraes in the Galactic nuclear bulge, is indeed older than that in the halo. Publication: The Astronomical Journal Pub Date: November 1992 DOI: 10.1086/116358 Bibcode: 1992AJ....104.1780L Keywords: Galactic Bulge; Galactic Evolution; Lyra Constellation; Metallicity; Galactic Halos; Milky Way Galaxy; Universe; Astrophysics; STARS: VARIABLES: RR LYRAE; GALAXY: FORMATION; EARLY UNIVERSE full text sources ADS | data products SIMBAD (7)