Redshifts of the Gravitational Lenses MG 0414+0534 and MG 0751+2716

John L. Tonry; Christopher S. Kochanek

doi:10.1086/300834

Gravitational Lenses

10.1007/3-540-55797-0 ◽

1992 ◽

Cited By ~ 6

Keyword(s):

Gravitational Lenses

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Fast automated analysis of strong gravitational lenses with convolutional neural networks

Nature ◽

10.1038/nature23463 ◽

2017 ◽

Vol 548 (7669) ◽

pp. 555-557 ◽

Cited By ~ 69

Author(s):

Yashar D. Hezaveh ◽

Laurence Perreault Levasseur ◽

Philip J. Marshall

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Automated Analysis ◽

Gravitational Lenses

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Out of sight, out of mind? The impact of correlated clustering in substructure lensing

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab448 ◽

2021 ◽

Author(s):

Alexandres Lazar ◽

James S Bullock ◽

Michael Boylan-Kolchin ◽

Robert Feldmann ◽

Onur Çatmabacak ◽

...

Keyword(s):

Dark Matter ◽

Principal Axis ◽

Major Axis ◽

Line Of Sight ◽

Gravitational Lenses ◽

Local Clustering ◽

Analytic Expression ◽

Halo Masses ◽

The Impact

Abstract A promising route for revealing the existence of dark matter structures on mass scales smaller than the faintest galaxies is through their effect on strong gravitational lenses. We examine the role of local, lens-proximate clustering in boosting the lensing probability relative to contributions from substructure and unclustered line-of-sight (LOS) haloes. Using two cosmological simulations that can resolve halo masses of Mhalo ≃ 109 M⊙ (in a simulation box of length Lbox ∼ 100 Mpc) and 107 M⊙ (Lbox ∼ 20 Mpc), we demonstrate that clustering in the vicinity of the lens host produces a clear enhancement relative to an assumption of unclustered haloes that persists to >20 Rvir. This enhancement exceeds estimates that use a two-halo term to account for clustering, particularly within 2 − 5 Rvir. We provide an analytic expression for this excess, clustered contribution. We find that local clustering boosts the expected count of 109 M⊙ perturbing haloes by ${\sim }35{{\ \rm per\ cent}}$ compared to substructure alone, a result that will significantly enhance expected signals for low-redshift (zl ≃ 0.2) lenses, where substructure contributes substantially compared to LOS haloes. We also find that the orientation of the lens with respect to the line of sight (e.g. whether the line of sight passes through the major axis of the lens) can also have a significant effect on the lensing signal, boosting counts by an additional $\sim 50{{\ \rm per\ cent}}$ compared to a random orientations. This could be important if discovered lenses are biased to be oriented along their principal axis.

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Influence of Gravitational Lensing on Estimates of Ω in Neutral Hydrogen

Symposium - International Astronomical Union ◽

10.1017/s0074180900231021 ◽

1996 ◽

Vol 173 ◽

pp. 97-98

Author(s):

Matthias Bartelmann ◽

Abraham Loeb

Keyword(s):

Observational Data ◽

Gravitational Lensing ◽

Column Density ◽

Spiral Galaxies ◽

Neutral Hydrogen ◽

Absorption Lines ◽

Gravitational Lenses ◽

High Column

A wealth of observational data supports the commonly held view that damped Lyman-α (Lyα) absorption in QSO spectra is associated with neutral-hydrogen (HI) disks in spiral galaxies. Most of the HI probed by QSO absorption lines is traced by damped Lyα lines because of their high column densities, N > 1020 cm–2. The spiral galaxies hosting the HI disks can act as gravitational lenses on the QSOs. If the HI column density increases towards the center of the disks, as suggested by observations of local galaxies, the magnification bias preferentially selects for high column-density systems. The estimates of HI in damped Lyα systems can then systematically be distorted by gravitational lensing.

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Poor Groups Around Strong Gravitational Lenses

Proceedings of the International Astronomical Union ◽

10.1017/s174392130600634x ◽

2006 ◽

Vol 2 (S235) ◽

pp. 230-230

Author(s):

Ivelina Momcheva ◽

Kurtis Williams ◽

Ann Zabludoff ◽

Charles Keeton

Keyword(s):

Galaxy Evolution ◽

Velocity Dispersion ◽

Gravitational Lenses ◽

Local Universe ◽

Groups Of Galaxies ◽

Hot Gas ◽

Gas Kinematics ◽

The Galaxy ◽

Group Centroid ◽

Group Galaxy

AbstractPoor groups are common and interactive environments for galaxies, and thus are important laboratories for studying galaxy evolution. Unfortunately, little is known about groups at z ≥ 0.1, because of the difficulty in identifying them in the first place. Here we present results from our ongoing survey of the environments of strong gravitational lenses, in which we have so far discovered six distant (z ≥ 0.5) groups of galaxies. As in the local Universe, the highest velocity dispersion groups contain a brightest member spatially coincident with the group centroid, whereas lower-dispersion groups tend to have an offset brightest group galaxy. This suggests that higher-dispersion groups are more dynamically relaxed than lower-dispersion groups and that at least some evolved groups exist by z ~ 0.5. We also compare the galaxy and hot gas kinematics with those of similarly distant clusters and of nearby groups.

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