2003/07/09 by R. A. E. Fosbury, M. Villar‐Martín, M. Villar-Martin +14 · 4 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Emission spectrum #Equivalent width #Galaxies: Formation, Evolution, Phenomena #Galaxy #Metallicity #Nebula #Physics #ROSAT #Redshift #Spectral line #Star cluster #Star formation #Stars #Stellar, planetary, and galactic studies #Supernova #astro-ph
paper · pdf · doi:10.1086/378228
published as Astrophys.J.596:797-809,2003 · 37 pages, 9 color figures; ApJ in press (v596 n2 October 20, 2003)
arxiv created 2003/07/09 · openalex publication_date 2003/10/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The Lynx arc, with a redshift of 3.357, was discovered during spectroscopic follow-up of the z = 0.570 cluster RX J0848+4456 from the ROSAT Deep Cluster Survey. The arc is characterized by a very red R - K color and strong, narrow emission lines. Analysis of HST WFPC2 imaging and Keck optical and infrared spectroscopy shows that the arc is an H II galaxy magnified by a factor of ~10 by a complex cluster environment. The high intrinsic luminosity, the emission-line spectrum, the absorption components seen in Lyα and C IV, and the rest-frame ultraviolet continuum are all consistent with a simple H II region model containing ~10 6 hot O stars. The best-fit parameters for this model imply a very hot ionizing continuum ( T BB ≃ 80,000 K), a high ionization parameter (log U ≃ -1), and a low nebular metallicity ( Z / Z ☉ ≃ 0.05). The narrowness of the emission lines requires a low mass-to-light ratio for the ionizing stars, suggestive of an extremely low metallicity stellar cluster. The apparent overabundance of silicon in the nebula could indicate enrichment by past pair-instability supernovae, requiring stars more massive than ~140 M ☉ .