GeminiFocus December 2012 | Page 28

Figure 4. Left: Portion of a Gemini spectrum of PS1-11bam containing several interstellar absorption features of Fe II and Mg II at z = 1.566 (black). The error spectrum is shown in blue, and for comparison, the composite GRB spectrum in red. Right: A zoom-in on the relevant Fe II and Mg II lines demonstrates the similarity to GRB absorption spectra. The host galaxy also appears in the emission of [O II] 3727. 28 equivalent widths of Mg II and Fe II in this case are intermediate between typical observations of quasars (which tend to probe galaxy outskirts) and GRBs (which tend to probe the central regions of galaxies), and they are much lower than those of star-forming galaxies at the same redshift. This first direct demonstration that ultraluminous supernovae can reveal distant galaxies suggests that the next generation of imaging surveys and spectroscopy from extremely large telescopes could be applied to galaxies in the earliest days of the universe. Nancy A. Levenson is Deputy Director and Head of Science at Gemini Observatory and can be reached at: [email protected] GeminiFocus December2012