%0 Generic %1 bosman2017search %A Bosman, Sarah E. I. %A Becker, George D. %A Haehnelt, Martin G. %A Hewett, Paul C. %A McMahon, Richard G. %A Mortlock, Daniel J. %A Simpson, Chris %A Venemans, Bram P. %D 2017 %K high metals redshift %T A deep search for metals near redshift 7: the line-of-sight towards ULAS J1120+0641 %U http://arxiv.org/abs/1705.08925 %X We present a search for metal absorption line systems at the highest redshifts to date using a deep (30h) VLT/X-Shooter spectrum of the z = 7.084 quasi-stellar object (QSO) ULAS J1120+0641. We detect seven intervening systems at z > 5.5, with the highest-redshift system being a C IV absorber at z = 6.51. We find tentative evidence that the mass density of C IV remains flat or declines with redshift at z < 6, while the number density of C II systems remains relatively flat over 5 < z < 7. These trends are broadly consistent with models of chemical enrichment by star formation-driven winds that include a softening of the ultraviolet background towards higher redshifts. We find a larger number of weak ( W_rest < 0.3A ) Mg II systems over 5.9 < z < 7.0 than predicted by a power-law fit to the number density of stronger systems. This is consistent with trends in the number density of weak Mg II systems at z = 2.5, and suggests that the mechanisms that create these absorbers are already in place at z = 7. Finally, we investigate the associated narrow Si IV, C IV, and N V absorbers located near the QSO redshift, and find that at least one component shows evidence of partial covering of the continuum source.

@misc{bosman2017search, abstract = {We present a search for metal absorption line systems at the highest redshifts to date using a deep (30h) VLT/X-Shooter spectrum of the z = 7.084 quasi-stellar object (QSO) ULAS J1120+0641. We detect seven intervening systems at z > 5.5, with the highest-redshift system being a C IV absorber at z = 6.51. We find tentative evidence that the mass density of C IV remains flat or declines with redshift at z < 6, while the number density of C II systems remains relatively flat over 5 < z < 7. These trends are broadly consistent with models of chemical enrichment by star formation-driven winds that include a softening of the ultraviolet background towards higher redshifts. We find a larger number of weak ( W_rest < 0.3A ) Mg II systems over 5.9 < z < 7.0 than predicted by a power-law fit to the number density of stronger systems. This is consistent with trends in the number density of weak Mg II systems at z = 2.5, and suggests that the mechanisms that create these absorbers are already in place at z = 7. Finally, we investigate the associated narrow Si IV, C IV, and N V absorbers located near the QSO redshift, and find that at least one component shows evidence of partial covering of the continuum source.}, added-at = {2017-05-26T10:12:24.000+0200}, author = {Bosman, Sarah E. I. and Becker, George D. and Haehnelt, Martin G. and Hewett, Paul C. and McMahon, Richard G. and Mortlock, Daniel J. and Simpson, Chris and Venemans, Bram P.}, biburl = {https://www.bibsonomy.org/bibtex/247ecabd108d62374aa3924e7c8ad366b/miki}, description = {[1705.08925] A deep search for metals near redshift 7: the line-of-sight towards ULAS J1120+0641}, interhash = {faa87768ac8f6e9aeafae938190cfa23}, intrahash = {47ecabd108d62374aa3924e7c8ad366b}, keywords = {high metals redshift}, note = {cite arxiv:1705.08925Comment: 18 pages, 23 figures, accepted for publication in MNRAS}, timestamp = {2017-05-26T10:12:24.000+0200}, title = {A deep search for metals near redshift 7: the line-of-sight towards ULAS J1120+0641}, url = {http://arxiv.org/abs/1705.08925}, year = 2017 }