KODIAQ-Z: Metals and Baryons in the Cool Intergalactic and Circumgalactic Gas at 2.2

Lehner, Nicolas; Kopenhafer, Claire; O'Meara, John; Howk, J. Christopher; Fumagalli, Michele; Prochaska, Jason; Acharyya, Ayan; O'Shea, Brian; Peeples, Molly; Tumlinson, Jason; Hummels, Cameron

doi:10.48550/arxiv.2112.03304

Cited by 4 publications

(12 citation statements)

References 101 publications

(236 reference statements)

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“…These high resolution simulations show that the IGM can be clustered in small-scale, dense-cloud structures that are not observed in lower resolution simulations (Mandelker et al 2021). In these simulations, the metallicity of this denser gas is [X/H] < −3 at z 3, but according to the metallicity evolution of these absorbers (Lehner et al 2021), the metallicity of such structures is expected to increase at lower redshift. Future high resolution simulations should shed light on the possibility of such dense IGM structures being common at z < 1.…”

Section: Origins Of the Low-metallicity Absorbersmentioning

confidence: 69%

“…14.5 at z 2 (Lehner et al 2016(Lehner et al , 2021. This survey covers a similar H I column density regime as CCC, but thanks to the higher S/N of the Keck/HIRES spectra, they are able to explore even lower N (H I) absorbers.…”

Section: The Cubs Surveymentioning

confidence: 97%

“…The low-metallicity systems could be associated with the IGM or the CGM. (Systems with [X/H] < −2 imply no redshift evolution in their metal content since z ≈ 2-3, since a majority of the MDF for pLLSs/LLSs lies below this value at these redshifts; Lehner et al 2016Lehner et al , 2021 Here we present the galaxy associations we find for each absorber and an overview of the associated galaxy sample characteristics. There are no apparent correlations between the absorber column densities and host galaxy properties discussed in this section.…”

Section: The Galaxy Properties Of the H I-selected Absorbersmentioning

confidence: 99%

“…Similar properties are also observed at higher redshifts (e.g.,Fumagalli et al 2016;Lehner et al 2016Lehner et al , 2021.…”

mentioning

confidence: 99%

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The Bimodal Absorption System Imaging Campaign (BASIC) I. A Dual Population of Low-metallicity Absorbers at z $<1$

Berg¹,

Lehner²,

Howk³

et al. 2022

Preprint

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The bimodal absorption system imaging campaign (BASIC) aims to characterize the galaxy environments of a sample of 36 H I-selected partial Lyman limit systems (pLLSs) and Lyman limit systems (LLSs) in 23 QSO fields at z 1. These pLLSs/LLSs provide a unique sample of absorbers with unbiased and well-constrained metallicities, allowing us to explore the origins of metal-rich and low-metallicity circumgalactic medium (CGM) at z < 1. Here we present Keck/KCWI and VLT/MUSE observations of 11 of these QSO fields (19 pLLSs) that we combine with HST/ACS imaging to identify and characterize the absorber-associated galaxies at 0.16 z 0.84. We find 23 unique absorberassociated galaxies, with an average of one associated galaxy per absorber. For seven absorbers, all with < 10% solar metallicities, we find no associated galaxies with log M 9.0 within ρ/R vir and |∆v|/v esc ≤ 1.5 with respect to the absorber. We do not find any strong correlations between the metallicities or H I column densities of the gas and most of the galaxy properties, except for the stellar mass of the galaxies: the low-metallicity ([X/H] ≤ −1.4) systems have a probability of 0.39 +0.16 −0.15 for having a host galaxy with log M ≥ 9.0 within ρ/R vir ≤ 1.5, while the higher metallicity absorbers have a probability of 0.78 +0.10 −0.13 . This implies metal-enriched pLLSs/LLSs at z < 1 are typically associated with the CGM of galaxies with log M > 9.0, whereas low-metallicity pLLSs/LLSs are found in more diverse locations, with one population arising in the CGM of galaxies and another more broadly distributed in overdense regions of the universe. Using absorbers not associated with galaxies, we estimate the unweighted geometric mean metallicity of the intergalactic medium to be [X/H] −2.1 at z < 1, which is lower than previously estimated.

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Section: Origins Of the Low-metallicity Absorbersmentioning

confidence: 69%

Section: The Cubs Surveymentioning

confidence: 97%

Section: The Galaxy Properties Of the H I-selected Absorbersmentioning

confidence: 99%

“…Similar properties are also observed at higher redshifts (e.g.,Fumagalli et al 2016;Lehner et al 2016Lehner et al , 2021.…”

mentioning

confidence: 99%

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The Bimodal Absorption System Imaging Campaign (BASIC) I. A Dual Population of Low-metallicity Absorbers at z $<1$

Berg¹,

Lehner²,

Howk³

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

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“…High-resolution spectroscopic observations of quasars with long exposure times are usually the choice to study metal lines in the Lyα forest or associated with the Lyα forest (e.g., Ellison et al 2000;Schaye et al 2003;Simcoe et al 2004;Lehner et al 2019Lehner et al , 2021. For example, Lehner et al (2021) study 2.2 z 3.6 H I-selected absorbers with neutral hydrogen column density in the range of 14.6 ≤ log(N HI /cm −2 ) ≤ 20.…”

Section: Introductionmentioning

confidence: 99%

Metal Lines Associated with the Lyman-alpha Forest from eBOSS Data

Yang,

Zheng,

Bourboux

et al. 2022

Preprint

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We investigate the metal species associated with the Lyα forest in the eBOSS quasar spectra. Metal absorption lines are revealed in the stacked spectra from cross-correlating the selected Lyα absorbers in the forest and the flux fluctuation field. Up to 13 metal species are identified associated with relatively strong Lyα absorbers (those with flux fluctuation −1.0 < δ Lyα < −0.6 and with neutral hydrogen column density of ∼ 10 15−16 cm −2 ) over absorber redshift range of 2 < z abs < 4. The column densities of these species decrease toward higher redshift and for weaker Lyα absorbers. From modelling the column densities of various species, we find that the column density pattern suggests contributions from multiple gas components both in the circumgalactic medium (CGM) and in the intergalactic medium (IGM). While the low-ionization species (e.g., C II, Si II, and Mg II) can be explained by highdensity, cool gas (T ∼ 10 4 K) from the CGM, the high-ionization species may reside in low-density or high-temperature gas in the IGM. The measurements provide inputs to model metal contamination in the Lyα forest baryon acoustic oscillations measurement. Comparison with metal absorptions in highresolution quasar spectra and with hydrodynamic galaxy formation simulations can further elucidate the physical conditions of these Lyα absorbers.

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MUSE Analysis of Gas around Galaxies (MAGG) – IV. The gaseous environment of z ∼ 3–4 Ly α emitting galaxies

Lofthouse

Fumagalli

Fossati

et al. 2022

Monthly Notices of the Royal Astronomical Society

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We study the link between galaxies and H i-selected absorption systems at z ∼ 3 − 4 in the MUSE Analysis of Gas around Galaxies (MAGG) survey, an ESO large programme consisting of integral field spectroscopic observations of 28 quasar fields hosting 61 strong absorbers with $\rm N_{\rm HI}\gtrsim 10^{16.5}~\rm cm^{-2}$. We identify 127 Lyα emitting galaxies (LAEs) around the absorbers, corresponding to a detection rate of 82±16 per cent. The luminosity function of these LAEs is ≈5 times higher in normalization than the field population and we detect a significant clustering of galaxies with respect to the gas, confirming that high column density absorbers and LAEs trace each other. Between 30 and 40 per cent of the absorbers are associated with multiple LAEs, which lie preferentially along filaments. Galaxies in groups also exhibit a three times higher covering factor of optically-thick gas compared to isolated systems. No significant correlations are identified between the emission properties of LAEs and the absorption properties of optically-thick gas clouds, except for a weak preference of brighter and multiple galaxies to reside near broad absorbers. Based on the measured impact parameters and the covering factor, we conclude that the near totality of optically-thick gas in the Universe can be found in the outer circumgalactic medium (CGM) of LAEs or in the intergalactic medium (IGM) in proximity to these galaxies. Thus, LAEs act as tracers of larger scale structures within which both galaxies and optically-thick clouds are embedded. The patchy and inhomogeneous nature of the CGM and IGM explains the lack of correlations between absorption and emission properties. This implies that very large samples are needed to unveil the trends that encode the properties of the baryon cycle.

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KODIAQ-Z: Metals and Baryons in the Cool Intergalactic and Circumgalactic Gas at 2.2

Cited by 4 publications

References 101 publications

The Bimodal Absorption System Imaging Campaign (BASIC) I. A Dual Population of Low-metallicity Absorbers at z $<1$

The Bimodal Absorption System Imaging Campaign (BASIC) I. A Dual Population of Low-metallicity Absorbers at z $<1$

Metal Lines Associated with the Lyman-alpha Forest from eBOSS Data

MUSE Analysis of Gas around Galaxies (MAGG) – IV. The gaseous environment of z ∼ 3–4 Ly α emitting galaxies

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