%0 Generic %1 Savaglio2011 %A Savaglio, S. %A Rau, A. %A Greiner, J. %A Krühler, T. %A McBreen, S. %A Hartmann, D. H. %A Updike, A. C. %A Filgas, R. %A Klose, S. %A Afonso, P. %A Clemens, C. %A Yoldaş, A. Küpcü %A E., F. Olivares %A Sudilovsky, V. %A Szokoly, G. %D 2011 %K grb supersolar %T Super-solar Metal Abundances in Two Galaxies at z ~ 3.57 revealed by the GRB 090323 Afterglow Spectrum %U http://arxiv.org/abs/1110.4642 %X We report on the surprisingly high metallicity measured in two absorption systems at high redshift, detected in the Very Large Telescope spectrum of the afterglow of the gamma-ray burst GRB 090323. The two systems, at redshift z=3.5673 and z=3.5774 (separation Delta v ~ 660 km/s), are dominated by the neutral gas in the interstellar medium of the parent galaxies. From the singly ionized zinc and sulfur, we estimate oversolar metallicities of Zn/H =+0.29+/-0.10 and S/H = +0.67+/- 0.34, in the blue and red absorber, respectively. These are the highest metallicities ever measured in galaxies at z>3. We propose that the two systems trace two galaxies in the process of merging, whose star formation and metallicity are heightened by the interaction. This enhanced star formation might also have triggered the birth of the GRB progenitor. As typically seen in star-forming galaxies, the fine-structure absorption SiII* is detected, both in G0 and G1. From the rest-frame UV emission in the GRB location, we derive a relatively high, not corrected for dust extinction, star-formation rate SFR ~ 6 Msun/yr. These properties suggest a possible connection between some high-redshift GRB host galaxies and high-z massive sub-millimeter galaxies, which are characterized by disturbed morphologies and high metallicities. Our result provides additional evidence that the dispersion in the chemical enrichment of the Universe at high redshift is substantial, with the existence of very metal rich galaxies less than two billion years after the Big Bang.

@misc{Savaglio2011, abstract = { We report on the surprisingly high metallicity measured in two absorption systems at high redshift, detected in the Very Large Telescope spectrum of the afterglow of the gamma-ray burst GRB 090323. The two systems, at redshift z=3.5673 and z=3.5774 (separation Delta v ~ 660 km/s), are dominated by the neutral gas in the interstellar medium of the parent galaxies. From the singly ionized zinc and sulfur, we estimate oversolar metallicities of [Zn/H] =+0.29+/-0.10 and [S/H] = +0.67+/- 0.34, in the blue and red absorber, respectively. These are the highest metallicities ever measured in galaxies at z>3. We propose that the two systems trace two galaxies in the process of merging, whose star formation and metallicity are heightened by the interaction. This enhanced star formation might also have triggered the birth of the GRB progenitor. As typically seen in star-forming galaxies, the fine-structure absorption SiII* is detected, both in G0 and G1. From the rest-frame UV emission in the GRB location, we derive a relatively high, not corrected for dust extinction, star-formation rate SFR ~ 6 Msun/yr. These properties suggest a possible connection between some high-redshift GRB host galaxies and high-z massive sub-millimeter galaxies, which are characterized by disturbed morphologies and high metallicities. Our result provides additional evidence that the dispersion in the chemical enrichment of the Universe at high redshift is substantial, with the existence of very metal rich galaxies less than two billion years after the Big Bang. }, added-at = {2011-10-24T18:37:00.000+0200}, author = {Savaglio, S. and Rau, A. and Greiner, J. and Krühler, T. and McBreen, S. and Hartmann, D. H. and Updike, A. C. and Filgas, R. and Klose, S. and Afonso, P. and Clemens, C. and Yoldaş, A. Küpcü and E., F. Olivares and Sudilovsky, V. and Szokoly, G.}, biburl = {https://www.bibsonomy.org/bibtex/220a40bd6aeef44bb3ac78575d5266d13/miki}, description = {[1110.4642] Super-solar Metal Abundances in Two Galaxies at z ~ 3.57 revealed by the GRB 090323 Afterglow Spectrum}, interhash = {112b2031671039dcd96dc0f1b2514f0c}, intrahash = {20a40bd6aeef44bb3ac78575d5266d13}, keywords = {grb supersolar}, note = {cite arxiv:1110.4642 Comment: accepted for publication in MNRAS}, timestamp = {2011-10-24T18:37:01.000+0200}, title = {Super-solar Metal Abundances in Two Galaxies at z ~ 3.57 revealed by the GRB 090323 Afterglow Spectrum}, url = {http://arxiv.org/abs/1110.4642}, year = 2011 }