2005/04/08 by J. Melbourne, S. A. Wright, M. Barczys +15 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.1086/430830
published as Astrophys.J.625:L27-L30,2005 · 6 pages, 4 figures, 1 table, accepted ApJL 2005
arxiv created 2005/04/08 · openalex publication_date 2005/05/02 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
The Center for Adaptive Optics Treasury Survey aims to combine deep Hubble Space Telescope ( HST ) images in the optical with deep Keck adaptive optics (AO) data in the near-infrared (NIR) to study distant galaxies, active galactic nuclei, and supernovae. We recently achieved an important new milestone by securing the first Keck laser guide star AO image of faint galaxies. Six galaxies with redshifts ranging from 0.3 to 1.0 were targeted in one pointing in the GOODS-S field. Two are Chandra Deep Field-South sources, XID-56 and XID-536, with complex morphologies suggestive of recent merger activity. Substructures seen in the NIR AO image (FWHM ~0 1), including multiple tight knots in XID-56 and a double nucleus in XID-536, are confirmed in the optical HST images. These structures are unresolved in the best seeing-limited (~0 5 FWHM) NIR images. Stellar population synthesis models of the substructures indicate that XID-56 is a gas-rich merger with a recent burst of star formation and significant amounts of dust. XID-536 appears to be a merger of two evolved stellar populations.