An inhomogeneous reference catalogue of identified intervening heavy element systems in spectra of QSOs

York, Donald G.; Yanny, B.; Crotts, Arlin; Carilli, C. L.; Garrison, Etoi; Matheson, Leigh

doi:10.1093/mnras/250.1.24

Cited by 42 publications

(42 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, if a changing ionization state were driving the evolution, one would expect to observe, with the weakening of a highly ionized species like C iv, a corresponding increase in the strength of singly ionized species like C II and Si II (and a rapidly increasing incidence of optically thick LLSs). Recent results suggest that the singly ionized species in fact show a decrease in number similar to that of C IV at high redshift (York et al 1991;, and while the jury is still out on the LLSs, our own data suggest that there is no corresponding abrupt change in the number density for z> 1.5. Thus, we tentatively suggest that the observed evolution of C IV is controlled primarily by a systematic change in the abundance of C in the gas with time, and we are possibly observing the period of initial heavy-element enrichment in the outer parts of galaxies (cf.…”

Section: IV Absorption Systemsmentioning

confidence: 42%

The redshift evolution of QSO heavy-element absorption systems

Steidel

1992

PASP

View full text Add to dashboard Cite

show abstract

Section: IV Absorption Systemsmentioning

confidence: 42%

The redshift evolution of QSO heavy-element absorption systems

Steidel

1992

PASP

View full text Add to dashboard Cite

show abstract

“…While the exact relationship between high-redshift galaxies and heavy-element absorbers is unclear, it does appear that these systems are tracing the richer agglomerations of the clustering network, perhaps one that is similar to that found in detailed three-1 Contact D. E. Vanden Berk for a pre-(danvb=astro.as.utexas.edu) liminary version of the catalog ; see York et al (1991) for an earlier version. dimensional numerical investigations of the distribution of the richest Lya absorbers (see, e.g., Zhang et al 1998).…”

Section: Introductionmentioning

confidence: 98%

A New Measure of the Clustering of QSO Heavy‐Element Absorption‐Line Systems

Quashnock

Stein

1999

ApJ

View full text Add to dashboard Cite

We examine the line-of-sight clustering of QSO heavy-element absorption-line systems, using a new measure of clustering, called the reduced second moment measure, K(r), that directly measures the mean overdensity of absorbers on scales This measureÈwhile closely related to other second-order [r. measures such as the correlation function or the power spectrumÈhas a number of distinct statistical properties that make possible a continuous exploration of clustering as a function of scale. From a sample of 352 C IV absorbers with median redshift SzT \ 2.2, drawn from the spectra of 274 QSOs, we Ðnd that the absorbers are strongly clustered on scales from 1È20 h~1 Mpc. Furthermore, there appears to be a sharp break at 20 h~1 Mpc, with signiÐcant clustering on scales up to 100 h~1 Mpc in excess of that which would be expected from a smooth transition to homogeneity. There is no evidence of clustering on scales greater than 100 h~1 Mpc. These results suggest that strong C IV absorbers along a line of sight are indicators of clusters and possibly superclusters, a relationship that is supported by recent observations of "" Lyman break ÏÏ galaxies. Subject headings : cosmology : observations È intergalactic medium È large-scale structure of universe È methods : statistical È quasars : absorption lines

show abstract

“…2 Contact D. E. Vanden Berk for the latest version of (danvb=fnal.gov) the catalog ; see York et al (1991) for an earlier version. (1985), Crotts (1985), and Tytler, Sandoval, & Fan (1993).…”

Section: Introductionmentioning

confidence: 99%

A Measurement of the Three‐dimensional Clustering of CivAbsorption‐Line Systems on Scales of 5–1000h⁻¹Mpc

Loh¹,

Quashnock²,

Stein³

2001

ApJ

View full text Add to dashboard Cite

We examine the three-dimensional clustering of C IV absorption-line systems using an extensive catalog of QSO heavy-element absorbers drawn from the literature. We measure clustering by a volumeweighted integral of the correlation function called the reduced second-moment measure, and include information from both along and across QSO lines of sight, thus enabling a full determination of the three-dimensional clustering of absorbers, as well as a comparison of alongÈ and acrossÈline-of-sight clustering properties. Here we present the three-dimensional reduced second-moment estimator for a three-dimensional point process probed by one-dimensional lines of sight, and apply our algorithm to a sample of 345 C IV absorbers with median redshift SzT \ 2.2, drawn from the spectra of 276 QSOs. We conÐrm the existence of signiÐcant clustering on comoving scales of up to 100 h~1 Mpc and (q 0 \ 0.5), Ðnd that the additional acrossÈline-of-sight information strengthens the evidence for clustering on scales from 100 to 150 h~1 Mpc. There is no evidence of absorber clustering along or across lines of sight for scales from 150 to 1000 h~1 Mpc. We show that with a 300 times larger catalog, such as that to be compiled by the Sloan Digital Sky Survey (100,000 QSOs), use of the full three-dimensional estimator and acrossÈline-of-sight information will substantially increase clustering sensitivity. We Ðnd that standard errors are reduced by a factor of 2È20 on scales of 30È200 h~1 Mpc, in addition to the factor of (300)1@2 reduction from the larger sample size, e †ectively increasing the sample size by an extra factor of 4È400 at large distances. Subject headings : cosmology : observations È intergalactic medium È large-scale structure of universe È methods : statistical È quasars : absorption lines

show abstract

An inhomogeneous reference catalogue of identified intervening heavy element systems in spectra of QSOs

Cited by 42 publications

References 0 publications

The redshift evolution of QSO heavy-element absorption systems

The redshift evolution of QSO heavy-element absorption systems

A New Measure of the Clustering of QSO Heavy‐Element Absorption‐Line Systems

A Measurement of the Three‐dimensional Clustering of CivAbsorption‐Line Systems on Scales of 5–1000h⁻¹Mpc

Contact Info

Product

Resources

About

An inhomogeneous reference catalogue of identified intervening heavy element systems in spectra of QSOs

Cited by 42 publications

References 0 publications

The redshift evolution of QSO heavy-element absorption systems

The redshift evolution of QSO heavy-element absorption systems

A New Measure of the Clustering of QSO Heavy‐Element Absorption‐Line Systems

A Measurement of the Three‐dimensional Clustering of CivAbsorption‐Line Systems on Scales of 5–1000h−1Mpc

Contact Info

Product

Resources

About

A Measurement of the Three‐dimensional Clustering of CivAbsorption‐Line Systems on Scales of 5–1000h⁻¹Mpc