Alignment of faint galaxy images - Cosmological distortion and rotation

Valdés, F.; Tyson, J. A.; Jarvis, J. F.

doi:10.1086/161210

Cited by 61 publications

(48 citation statements)

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“…The author set a limit on the magnetic part of the Weyl tensor 40 of 200H −2 0 , which he describes as "about the best that can be done with this kind of measurement." Fortunately this has not remained the case -indeed it was improved upon by two orders of magnitude by Valdes et al (1983).…”

Section: The Current State Of Playmentioning

confidence: 99%

Observational probes of cosmic acceleration

et al. 2013

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The accelerating expansion of the universe is the most surprising cosmological discovery in many decades, implying that the universe is dominated by some form of "dark energy" with exotic physical properties, or that Einstein's theory of gravity breaks down on cosmological scales. The profound implications of cosmic acceleration have inspired ambitious efforts to understand its origin, with experiments that aim to measure the history of expansion and growth of structure with percent-level precision or higher. We review in detail the four most well established methods for making such measurements: Type Ia supernovae, baryon acoustic oscillations (BAO), weak gravitational lensing, and the abundance of galaxy clusters. We pay particular attention to the systematic uncertainties in these techniques and to strategies for controlling them at the level needed to exploit "Stage IV" dark energy facilities such as BigBOSS, LSST, Euclid, and WFIRST. We briefly review a number of other approaches including redshift-space distortions, the Alcock-Paczynski effect, and direct measurements of the Hubble constant H 0 . We present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from General Relativity, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and cosmic microwave background data. We also show the level of precision required for clusters or other methods to provide constraints competitive with those of these fiducial programs. We emphasize the value of a balanced program that employs several of the most powerful methods in combination, both to cross-check systematic uncertainties and to take advantage of complementary information. Surveys to probe cosmic acceleration produce data sets that support a wide range of scientific investigations, and they continue the longstanding astronomical tradition of mapping the universe in ever greater detail over ever larger scales.

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Section: The Current State Of Playmentioning

confidence: 99%

Observational probes of cosmic acceleration

et al. 2013

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“…This can be seen by writing down the convolution explicitly and changing the order of integration. Doing so we obtain (also see Valdes et al 1983):…”

Section: Description Of the Problemmentioning

confidence: 99%

On the shear estimation bias induced by the spatial variation of colour across galaxy profiles

Semboloni

Hoekstra

Huang

et al. 2013

Monthly Notices of the Royal Astronomical Society

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The spatial variation of the colour of a galaxy may introduce a bias in the measurement of its shape if the PSF profile depends on wavelength. We study how this bias depends on the properties of the PSF and the galaxies themselves. The bias depends on the scales used to estimate the shape, which may be used to optimise methods to reduce the bias. Here we develop a general approach to quantify the bias. Although applicable to any weak lensing survey, we focus on the implications for the ESA Euclid mission.Based on our study of synthetic galaxies we find that the bias is a few times 10 −3 for a typical galaxy observed by Euclid. Consequently, it cannot be neglected and needs to be accounted for. We demonstrate how one can do so using spatially resolved observations of galaxies in two filters. We show that HST observations in the F606W and F814W filters allow us to model and reduce the bias by an order of magnitude, sufficient to meet Euclid's scientific requirements. The precision of the correction is ultimately determined by the number of galaxies for which spatially-resolved observations in at least two filters are available. We use results from the Millennium Simulation to demonstrate that archival HST data will be sufficient for the tomographic cosmic shear analysis with the Euclid dataset.

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“…Kristian (1967) looked at this effect on photographic plates of six clusters of galaxies using the Palomar Telescope, but found nothing significant. Valdes, Tyson & Jarvis (1983) were the first who attempted to measure a coherent alignment of distant galaxies generated by large scale structures. They used about 40,000 randomly selected field galaxies with J magnitudes between 22.5 and 23.5, but, as Kristian, did not find any conclusive signal.…”

Section: Large-scale Structures and Cosmic Shearmentioning

confidence: 99%

Probing the Universe with Weak Lensing

Mellier

1999

Annu. Rev. Astron. Astrophys.

473

475

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Gravitational lenses can provide crucial information on the geometry of the Universe, on the cosmological scenario of formation of its structures as well as on the history of its components with look-back time. In this review, I focus on the most recent results obtained during the last five years from the analysis of the weak lensing regime. The interest of weak lensing as a probe of dark matter and the for study of the coupling between light and mass on scales of clusters of galaxies, large scale structures and galaxies is discussed first. Then I present the impact of weak lensing for the study of distant galaxies and of the population of lensed sources as function of redshift. Finally, I discuss the potential interest of weak lensing to constrain the cosmological parameters, either from pure geometrical effects observed in peculiar lenses, or from the coupling of weak lensing with the CMB.

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Alignment of faint galaxy images - Cosmological distortion and rotation

Cited by 61 publications

References 0 publications

Observational probes of cosmic acceleration

Observational probes of cosmic acceleration

On the shear estimation bias induced by the spatial variation of colour across galaxy profiles

Probing the Universe with Weak Lensing

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