A Multiply Imaged Luminous Infrared Galaxy behind the Bullet Cluster (1e0657-56)

We present evidence for a Spitzer-selected luminous infrared galaxy (LIRG) behind the Bullet Cluster (1E0657-56). The galaxy, originally identified in IRAC photometry as a multiply imaged source, has a spectral energy distribution consistent with a highly extincted (AV ∼ 3.3), strongly star-forming galaxy at z ∼ 2.7. Our strong gravitational lensing analysis of the cluster indicates that the magnifications are |μ| ∼ 25 and |μ| ∼ 50 for the two images of the galaxy. The implied infrared luminosity is consistent with the galaxy being a LIRG. The galaxy has an unlensed stellar mass of M∗ ∼ 2 × 10 10 M⊙, and a star formation rate of ∼ 50 M⊙ yr . With a lensed luminosity of 0.8 mJy at 24μm, this galaxy presents a unique opportunity for detailed study of an obscured starburst at this epoch, with the aim of understanding the connection between the different classes of dusty galaxies found at high redshift. Subject headings: galaxies: evolution, starburst — gravitational lensing – galaxies: clusters: general