TY - JOUR
T1 - The iron group abundance pattern of the damped lyman-alpha absorber at z = 1.3726 toward the qso 0935+417
AU - Meyer, David M.
AU - Lanzetta, Kenneth M.
AU - Wolfe, Arthur M.
N1 - Funding Information:
1Visiting Astronomer, Kitt Peak National Observatory, National Optical Astronomy Observatories, operated by AURA, Inc., under contract with the National Science Foundation.
Funding Information:
It is a pleasure to thank the KPNO staff for their expert assistance with the observations. This work was supported in part by the NSF through grant AST 93-15728 to Northwestern University.
PY - 1995/9/20
Y1 - 1995/9/20
N2 - We present high-resolution (18 km s-1), high S/N (≈50) observations of the Zn II Cr II, Fe II, Mn II, and Ti II absorption in the damped Lya system at 2 = 1.3726 toward the QSO 0935+417. We measure a Zn metallicity ([Zn/H] = -0.70) in this system that is about 3 times greater than those of the lower redshift damped absorbers toward 3C 286 and 0454+039 and comparable to those of the highest metallicity absorbers observed at higher redshifts. The Cr II and Fe II column densities yield gas-phase abundance ratios of [Cr/Zn] = -0.10 and [Fe/Zn] = -0.29 that are much greater than even those of low-density Galactic ISM sightlines and imply that the 0935+417 absorber is essentially a dust-free environment. We also find evidence of a Mn underabundance and a Ti overabundance that is consistent with the nucleosynthetic signature of a gas cloud with a base metallicity similar to that of metal-poor Galactic stars. In summary, the iron group abundance pattern of the 2 = 1.3726 absorber toward 0935+417 is what one might expect from a dust-free, metal-poor galaxy evolving on a metallicity track similar to that of the Milky Way.
AB - We present high-resolution (18 km s-1), high S/N (≈50) observations of the Zn II Cr II, Fe II, Mn II, and Ti II absorption in the damped Lya system at 2 = 1.3726 toward the QSO 0935+417. We measure a Zn metallicity ([Zn/H] = -0.70) in this system that is about 3 times greater than those of the lower redshift damped absorbers toward 3C 286 and 0454+039 and comparable to those of the highest metallicity absorbers observed at higher redshifts. The Cr II and Fe II column densities yield gas-phase abundance ratios of [Cr/Zn] = -0.10 and [Fe/Zn] = -0.29 that are much greater than even those of low-density Galactic ISM sightlines and imply that the 0935+417 absorber is essentially a dust-free environment. We also find evidence of a Mn underabundance and a Ti overabundance that is consistent with the nucleosynthetic signature of a gas cloud with a base metallicity similar to that of metal-poor Galactic stars. In summary, the iron group abundance pattern of the 2 = 1.3726 absorber toward 0935+417 is what one might expect from a dust-free, metal-poor galaxy evolving on a metallicity track similar to that of the Milky Way.
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U2 - 10.1086/309680
DO - 10.1086/309680
M3 - Article
AN - SCOPUS:79960842951
SN - 0004-637X
VL - 451
SP - L13-L16
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
ER -