Showing 1999 · astro-phShow all

7 papers · 2 filters

astro-ph1999★ 75 cited

The Metallicity Dependence of RR Lyrae Absolute Magnitudes from Synthetic Horizontal-Branch Models

Pierre Demarque, Robert Zinn, Young-Wook Lee +1

A grid of synthetic horizontal-branch (SHB) models based on HB evolutionary tracks with improved physics has been constructed to reconsider the theoretical calibration of the depen…

astro-ph1999★ 364 cited

Multiple Stellar Populations in the Globular Cluster omega Centauri as Tracers of a Merger Event

Young-Wook Lee, Jong-Myung Joo, Young-Jong Sohn +3

The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up a…

astro-ph1999★ 44 cited

On The Age Estimation of LBDS 53W091

Sukyoung YI, T. M. Brown, S. Heap +4

The recent spectral analysis of LBDS 53W091 by Spinrad and his collaborators has suggested that this red galaxy at z=1.55 is at least 3.5 Gyr old. This imposes an important constra…

astro-ph1999★ 27 cited

Astrometric Properties of Gravitational Binary-Microlens Events and Their Applications

Cheongho Han, Mun-Suk Chun, Kyongae Chang

In this paper, we study the astrometric properties of gravitational microlensing events caused by binary lenses. By investigating the centroid shifts for various types of binary-le…

astro-ph1999

Spectrophotometric Dating of Elliptical Galaxies in the Ultraviolet

Y. -W. Lee, J. -H. Woo, S. Yi +1

The UV upturn phenomenon observed in elliptical galaxies is attractive for its potential value as an age indicator of old stellar systems. We present our most recent population mod…

astro-ph1999★ 42 cited

Stellar Populations and the Local Group Membership of the Dwarf Galaxy DDO 210

Myung Gyoon Lee, Antonio Aparicio, Nikolay Tikonov +2

We present deep BVI CCD photometry of the stars in the dwarf galaxy DDO 210. The color-magnitude diagrams of DDO 210 show a well-defined red giant branch (RGB) and a blue plume. Th…

astro-ph1999★ 19 cited

Stellar Populations of the Dwarf Galaxy UKS 2323--326 in the Sculptor Group

Myung Gyoon Lee, Yong-Ik Byun

We present deep BVRI CCD photometry of the stars in the dwarf irregular galaxy UKS 2323-326 in the Sculptor Group. The color-magnitude diagrams of the measured stars in UKS 2323-32…