Properties of the Z =2.73 Galaxy, MS1512-CB58

Abstract

MS1512-cB58 is an z = 2.73 galaxy whose apparent brightness is amplified by30–50X due to gravitationally lensing. The restframe far-UV spectrum of cB58 that was obtained by KeckI/LRIS is ‘one of the best ultraviolet spectra of a starburst galaxy obtained at any redshift’ (Pettini et al., 2000). We have analyzed and modeled the spectrum of this galaxy in order to learn the properties of high-redshift galaxies. We find that our model spectrum is a near match to the observed spectrum of cB58 if the galaxy has a SMC-like metallicity, and has a Salpeter IMF extending up to ~ 100 M _⊙. The spectrum of cB58 also shows many absorption lines formed in a giant, expanding gas shell surrounding the star-forming complex. We show preliminary findings of the properties of the giant HII region based on our CLOUDSPEC model.