%0 Generic %1 kruhler2015hosts %A Krühler, T. %A Malesani, D. %A Fynbo, J. P. U. %A Hartoog, O. E. %A Hjorth, J. %A Jakobsson, P. %A Perley, D. A. %A Rossi, A. %A Schady, P. %A Schulze, S. %A Tanvir, N. R. %A Vergani, S. D. %A Wiersema, K. %A Afonso, P. M. J. %A Bolmer, J. %A Cano, Z. %A Covino, S. %A D'Elia, V. %A Postigo, A. de Ugarte %A Filgas, R. %A Friis, M. %A Graham, J. F. %A Greiner, J. %A Goldoni, P. %A Gomboc, A. %A Hammer, F. %A Japelj, J. %A Kann, D. A. %A Kaper, L. %A Klose, S. %A Levan, A. J. %A Leloudas, G. %A Milvang-Jensen, B. %A Guelbenzu, A. Nicuesa %A Palazzi, E. %A Pian, E. %A Piranomonte, S. %A Sanchez-Ramirez, R. %A Savaglio, S. %A Selsing, J. %A Tagliaferri, G. %A Vreeswijk, P. M. %A Watson, D. J. %A Xu, D. %D 2015 %K cosmic grb time %T GRB hosts through cosmic time - VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1 < z < 3.6 %U http://arxiv.org/abs/1505.06743 %X We present data and initial results from VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1<z<3.6, the largest sample of GRB host spectroscopy available to date. The majority of our GRBs was detected by Swift and 76% are at 0.5<z<2.5 with a median z~1.6. Based on Balmer and/or forbidden lines of oxygen, nitrogen and neon, we measure systemic redshifts, star-formation rates, visual attenuations (A_V), oxygen abundances and emission-line widths (sigma). We find a strong change of the typical physical properties of GRB hosts with redshift. The median SFR, for example, increases from ~0.6 M_sun/yr at z~0.6 up to ~15 M_sun/yr at z~2. A higher ratio of OIII/OII at higher redshifts leads to an increasing distance of GRB-selected galaxies to the locus of local galaxies in the BPT diagram. Oxygen abundances of the galaxies are distributed between 12+log(O/H)=7.9 and 12+log(O/H)=9.0 with a median of 12+log(O/H)~8.5. The fraction of GRB-selected galaxies with super-solar metallicities is around 20% at z<1 in the adopted metallicity scale. This is significantly less than the fraction of star-formation in similar galaxies, illustrating that GRBs are scarce in high-metallicity environments. At z~3, sensitivity limits us to probing only the most luminous GRB hosts for which we derive metallicities of Z ~< 0.5 Z_sun. Together with a high incidence of galaxies with similar metallicity in our sample at z~1.5, this indicates that the metallicity dependence observed at low redshift will not be dominant at z~3.

@misc{kruhler2015hosts, abstract = {We present data and initial results from VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1<z<3.6, the largest sample of GRB host spectroscopy available to date. The majority of our GRBs was detected by Swift and 76% are at 0.5<z<2.5 with a median z~1.6. Based on Balmer and/or forbidden lines of oxygen, nitrogen and neon, we measure systemic redshifts, star-formation rates, visual attenuations (A_V), oxygen abundances and emission-line widths (sigma). We find a strong change of the typical physical properties of GRB hosts with redshift. The median SFR, for example, increases from ~0.6 M_sun/yr at z~0.6 up to ~15 M_sun/yr at z~2. A higher ratio of [OIII]/[OII] at higher redshifts leads to an increasing distance of GRB-selected galaxies to the locus of local galaxies in the BPT diagram. Oxygen abundances of the galaxies are distributed between 12+log(O/H)=7.9 and 12+log(O/H)=9.0 with a median of 12+log(O/H)~8.5. The fraction of GRB-selected galaxies with super-solar metallicities is around 20% at z<1 in the adopted metallicity scale. This is significantly less than the fraction of star-formation in similar galaxies, illustrating that GRBs are scarce in high-metallicity environments. At z~3, sensitivity limits us to probing only the most luminous GRB hosts for which we derive metallicities of Z ~< 0.5 Z_sun. Together with a high incidence of galaxies with similar metallicity in our sample at z~1.5, this indicates that the metallicity dependence observed at low redshift will not be dominant at z~3.}, added-at = {2015-05-27T11:11:10.000+0200}, author = {Krühler, T. and Malesani, D. and Fynbo, J. P. U. and Hartoog, O. E. and Hjorth, J. and Jakobsson, P. and Perley, D. A. and Rossi, A. and Schady, P. and Schulze, S. and Tanvir, N. R. and Vergani, S. D. and Wiersema, K. and Afonso, P. M. J. and Bolmer, J. and Cano, Z. and Covino, S. and D'Elia, V. and Postigo, A. de Ugarte and Filgas, R. and Friis, M. and Graham, J. F. and Greiner, J. and Goldoni, P. and Gomboc, A. and Hammer, F. and Japelj, J. and Kann, D. A. and Kaper, L. and Klose, S. and Levan, A. J. and Leloudas, G. and Milvang-Jensen, B. and Guelbenzu, A. Nicuesa and Palazzi, E. and Pian, E. and Piranomonte, S. and Sanchez-Ramirez, R. and Savaglio, S. and Selsing, J. and Tagliaferri, G. and Vreeswijk, P. M. and Watson, D. J. and Xu, D.}, biburl = {https://www.bibsonomy.org/bibtex/22fc42fa0d89e378f8c9d0b0d8951b620/miki}, description = {[1505.06743] GRB hosts through cosmic time - VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1 &lt; z &lt; 3.6}, interhash = {32e665a9a8f3b26426452eac3606907d}, intrahash = {2fc42fa0d89e378f8c9d0b0d8951b620}, keywords = {cosmic grb time}, note = {cite arxiv:1505.06743Comment: 33 pages, 20 figures, submitted to A&A, comments very welcome}, timestamp = {2015-05-27T11:11:10.000+0200}, title = {GRB hosts through cosmic time - VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1 < z < 3.6}, url = {http://arxiv.org/abs/1505.06743}, year = 2015 }