2008/03/05 by Remi A. Cabanac, Rémi A. Cabanac, David Valls-Gabaud +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.13157.x
MNRAS, in press. Figure 2 degraded to match arXiv file size limits
arxiv created 2008/03/05 · openalex publication_date 2008/04/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We recently reported the discovery of FORJ0332−3557, a lensed Lyman-break galaxy at z= 3.77 in a remarkable example of strong galaxy–galaxy gravitational lensing. We present here a medium-resolution rest-frame ultraviolet (UV) spectrum of the source, which appears to be similar to the well-known Lyman-break galaxy MS1512−cB58 at z= 2.73. The spectral energy distribution is consistent with a stellar population of less than 30 Ma, with an extinction of Av= 0.5 mag and an extinction-corrected star formation rate SFRUV of 200–300 h−170 M⊙ a−1. The Lyα line exhibits a damped profile in absorption produced by a column density of about NH i= (2.5 ± 1.0) × 1021cm−2, superimposed on an emission line shifted both spatially (0.5 arcsec with respect to the UV continuum source) and in velocity space (+830 km s−1 with respect to the low-ionization absorption lines from its interstellar medium), a clear signature of outflows with an expansion velocity of about 270 km s−1. A strong emission line from He iiλ164.04 nm indicates the presence of Wolf–Rayet stars and reinforces the interpretation of a very young starburst. The metallic lines indicate subsolar abundances of elements Si, Al and C in the ionized gas phase.