An Efficient Search for Gravitationally Lensed Radio Lobes

Lehár, Joseph; Buchalter, Ari; McMahon, R. G.; Kochanek, C. S.; Muxlow, T. W. B.

doi:10.1086/318367

Cited by 21 publications

(27 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lenses rejected based on their discovery method (i.e. lens–galaxy selected, as opposed to source selected) are: Q2237+0305 (Huchra et al 1985); CFRS03.1077 (Crampton et al 2002); FIRST J0816+5003 (Lehár et al 2001). We have also rejected all the lens candidates discovered in the Hubble Space Telescope HST medium deep survey (Ratnatunga, Griffiths & Ostrander 1999): HST14176+5226; HST12531− 2914; HST14164+5215; HST15433+5352; HST01247+ 0532; HST01248+0531; HST16302+8230; HST16309+5215; HST12369+6212; HST18078+4600; and in the Hubble Deep Fields: HDFS2232509–603243 (Barkana, Blandford & Hogg 1999).…”

Section: Sample Selectionmentioning

confidence: 99%

The redshift distribution of gravitational lenses revisited: constraints on galaxy mass evolution

Ofek¹,

Rix²,

Maoz³

2003

Monthly Notices of the Royal Astronomical Society

125

174

View full text Add to dashboard Cite

The redshifts of lens galaxies in known gravitational lens systems probe the volume distribution of the lensing mass. Following earlier work by Kochanek, we rederive the lens–redshift probability distribution, allowing for mass and number density evolution of the lensing galaxies, and apply this test to a much enlarged sample of lens systems. From a literature survey of all known lenses, we have selected an unbiased sample of 15 lenses with complete redshift information. For a flat universe and no lens evolution, we can only put an upper limit on the cosmological constant of ΩΛ < 0.89 at the 95 per cent confidence limit (CL). ΩΛ≈ 0.7 and no evolution is consistent with the data. Allowing for evolution in an Ωm= 0.3, ΩΛ= 0.7 cosmology, we find that the best‐fitting evolution in σ* (i.e. the characteristic velocity dispersion in a Schechter‐like function) of early‐type galaxies, in the redshift range z∼ 0 to 1, is d log [σ*(z)]/dz=−0.10 ± 0.06. This is consistent with no evolution and implies that, at 95 per cent CL, σ* of early‐type galaxies at z∼ 1 was at least 63 per cent of its current value. Alternatively, if there is no mass evolution, a present‐day value of σ* > 175 km s−1 for elliptical galaxies is required (95 per cent CL).

show abstract

Section: Sample Selectionmentioning

confidence: 99%

The redshift distribution of gravitational lenses revisited: constraints on galaxy mass evolution

Ofek¹,

Rix²,

Maoz³

2003

Monthly Notices of the Royal Astronomical Society

125

174

View full text Add to dashboard Cite

show abstract

“…As there was no radio‐spectral index selection imposed on targets in the MG‐VLA sample, some lensing events may have been missed because of the difficulty of recognizing multiply‐imaged single sources in a sample in which many of the steep‐spectrum sources have intrinsically complex structures (Kochanek & Lawrence 1990). However, such surveys do find examples where radio lobes are lensed into rings and this has been exploited systematically by Lehár et al (2001).…”

Section: Introductionmentioning

confidence: 99%

The Cosmic Lens All-Sky Survey - II. Gravitational lens candidate selection and follow-up

Browne¹,

Wilkinson²,

Jackson³

et al. 2003

Monthly Notices of the Royal Astronomical Society

303

View full text Add to dashboard Cite

We report the final results of the search for gravitationally lensed flat‐spectrum radio sources found in the combination of CLASS (Cosmic Lens All‐Sky Survey) and JVAS (Jodrell Bank VLA Astrometric Survey). VLA (Very Large Array) observations of 16 503 sources have been made, resulting in the largest sample of arcsec‐scale lens systems available. Contained within the 16 503 sources is a complete sample of 11 685 sources which have two‐point spectral indices between 1.4 and 5 GHz flatter than −0.5, and 5‐GHz flux densities ≥30 mJy. A subset of 8958 sources form a well‐defined statistical sample suitable for analysis of the lens statistics. We describe the systematic process by which 149 candidate lensed sources were picked from the statistical sample on the basis of possessing multiple compact components in the 0.2‐arcsec resolution VLA maps. Candidates were followed up with 0.05‐arcsec resolution MERLIN and 0.003‐arcsec VLBA observations at 5 GHz and rejected as lens systems if they failed well‐defined surface brightness and/or morphological tests. To illustrate the candidate elimination process, we show examples of sources representative of particular morphologies that have been ruled out by the follow‐up observations. 194 additional candidates, not in the well‐defined sample, were also followed up. Maps for all the candidates can be found on the World Wide Web at http://www.jb.man.ac.uk/research/gravlens/index.html. We summarize the properties of each of the 22 gravitational lens systems in JVAS/CLASS. 12 are double‐image systems, nine are four‐image systems and one is a six‐image system. 13 constitute a statistically well‐defined sample giving a point‐source lensing rate of 1:690 ± 190. The interpretation of the results in terms of the properties of the lensing galaxy population and cosmological parameters will be published elsewhere.

show abstract

“…The data are homogeneously reduced with typical astrometric accuracies of 3 mas or better (checked on VLBI lenses), and initially fit with a series of standard photometric and gravitational lens models (e.g. Lehár et al 1998).…”

Section: Introductionmentioning

confidence: 99%

Results from the CASTLES survey of gravitational lenses

Kochanek¹,

Falco²,

Impey³

et al. 1999

The 9th Astrophysics Conference: After the Dark Ages, When Galaxies Were Young (The Universe at 2Self Cite

28
2
24
0

View full text Add to dashboard Cite

Abstract. We show that most gravitational lenses lie on the passively evolving fundamental plane for early-type galaxies. For burst star formation models (1 Gyr of star formation, then quiescence) in low 120 cosmologies, the stellar populations of the lens galaxies must have formed at zf ~ 2. Typical lens galaxies contain modest amounts of patchy extinction, with a median differential extinction for the optical (radio) selected lenses of AE(B -V) = 0.04 (0.07) mag. The dust can be used to determine both extinction laws and lens redshifts. For example, the zt = 0.96 elliptical lens in MG 0414+0534 has an Rv = 1.7 -4-0.1 mean extinction law. Arc and ring images of the quasar and AGN source host galaxies are commonly seen in NICMOS H band observations. The hosts are typically blue, L g L. galaxies.

show abstract

An Efficient Search for Gravitationally Lensed Radio Lobes

Cited by 21 publications

References 37 publications

The redshift distribution of gravitational lenses revisited: constraints on galaxy mass evolution

The redshift distribution of gravitational lenses revisited: constraints on galaxy mass evolution

The Cosmic Lens All-Sky Survey - II. Gravitational lens candidate selection and follow-up

Results from the CASTLES survey of gravitational lenses

Contact Info

Product

Resources

About