On the Cosmic Evolution of Fe/Mg in QSO Absorption Line Systems

Abstract

We investigate the variation of the ratio of the equivalent widths of the FeII$\lambda$2600 line to the MgII$\lambda \lambda$2796,2803 doublet as a function of redshift in a large sample of absorption lines drawn from the JHU-SDSS Absorption Line Catalog. We find that despite large scatter, the observed ratio shows a trend where the equivalent width ratio $\mathcal{R}\equiv W_{\mathrm{FeII}}/W_{\mathrm{MgII}}$ decreases monotonically with increasing redshift $z$ over the range $0.55\le z\le 1.90$. Selecting the subset of absorbers where the signal-to-noise ratio of the MgII equivalent width $W_{\mathrm{MgII}}$ is $\ge$3 and modeling the equivalent width ratio distribution as a gaussian, we find that the mean of the gaussian distribution varies as $\mathcal{R}\propto (-0.045\pm 0.005)z$. We discuss various possible reasons for the trend. A monotonic trend in the Fe/Mg abundance ratio is predicted by a simple model where the abundances of Mg and Fe in the absorbing clouds are assumed to be the result of supernova ejecta and where the cosmic evolution in the SNIa and core-collapse supernova rates is related to the cosmic star-formation rate. If the trend in $\mathcal{R}$ reflects the evolution in the abundances, then it is consistent with the predictions of the simple model.

arXiv comment10 pages, 4 figures, final version published in MNRAS

References in corpus (46)

• The Sloan Digital Sky Survey: Technical Summary
• The chemical composition of the Sun
• The Seventh Data Release of the Sloan Digital Sky Survey
• Cosmic Star Formation History
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• Radiative Transfer in a Clumpy Universe: II. The Utraviolet Extragalactic Background
• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• Properties of galaxies reproduced by a hydrodynamic simulation
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies
• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• Chemical enrichment in cosmological, smoothed particle hydrodynamics simulations
• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• The Origin of the Galaxy Mass-Metallicity Relation and Implications for Galactic Outflows
• Simulating galactic outflows with kinetic supernova feedback
• Galaxy Evolution in Cosmological Simulations with Outflows II: Metallicities and Gas Fractions
• Evidence for Ubiquitous Collimated Galactic-Scale Outflows along the Star-Forming Sequence at z~0.5
• The radial and azimuthal profiles of Mg II absorption around 0.5 < z < 0.9 zCOSMOS galaxies of different colors, masses and environments
• A physical model for cosmological simulations of galaxy formation: multi-epoch validation
• Nucleosynthesis in Type Ia Supernovae
• Demographics and Physical Properties of Gas Out/Inflows at 0.4 < z < 1.4
• Type-Ia supernova rates and the progenitor problem, a review
• The delay-time distribution of type-Ia supernovae from Sloan II
• Theoretical uncertainties of the type Ia supernova rate
• Delay Time Distribution Measurement of Type Ia Supernovae by the Subaru/XMM-Newton Deep Survey and Implications for the Progenitor
• The JHU-SDSS metal absorption line catalog: redshift evolution and properties of Mg II absorbers
• Galactic Outflows in Absorption and Emission: Near-UV Spectroscopy of Galaxies at 1<z<2
• The Properties and Prevalence of Galactic Outflows at z = 1 in the Extended Groth Strip
• Simple Models of Metal-Line Absorption and Emission from Cool Gas Outflows
• Metal-enriched, sub-kiloparsec gas clumps in the circumgalactic medium of a faint z = 2.5 galaxy
• The Physical Conditions of Intermediate Redshift MgII Absorbing Clouds from Voigt Profile Analysis
• Modelling Element Abundances in Semi-analytic Models of Galaxy Formation
• Low and High Ionization Absorption Properties of Mg II Absorption-Selected Galaxies at Intermediate Redshifts. II. Taxonomy, Kinematics, and Galaxies
• The Impact of Galactic Feedback on the Circumgalactic Medium
• The Large-scale Distribution of Cool Gas around Luminous Red Galaxies
• Cosmic dust in MgII absorbers
• Exploring the diffuse interstellar bands with the Sloan Digital Sky Survey
• On the HI content, dust-to-gas ratio and nature of MgII absorbers
• Discovery Of Cold, Pristine Gas Possibly Accreting Onto An Overdensity Of Star-Forming Galaxies At Redshift z ~ 1.6
• The Chemical and Ionization Conditions in Weak Mg II Absorbers
• Precious Metals in SDSS Quasar Spectra II: Tracking the Evolution of Strong, 0.4 < z < 2.3 MgII Absorbers with Thousands of Systems
• The Kinematic Evolution of Strong MgII Absorbers
• Halo Masses of MgII absorbers at z\sim 0.5 from SDSS DR7
• Evolution of the Population of Very Strong MgII Absorbers
• Analysis of Low z Absorbers in the QSO Spectra

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• Average [O II] nebular emission associated with Mg II absorbers: Dependence on Fe II absorption
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• Kinematic analysis of an Ultra-Strong MgII absorber at z~1.13 linking to Circumgalactic Gas Structures