Pixel-based correction for Charge Transfer Inefficiency in the<i>Hubble Space Telescope</i>Advanced Camera for Surveys

Massey, Richard; Stoughton, Chris; Leauthaud, Alexie; Rhodes, Jason; Koekemoer, Anton M.; Ellis, Richard S.; Shaghoulian, Edgar

doi:10.1111/j.1365-2966.2009.15638.x

Cited by 168 publications

(189 citation statements)

References 29 publications

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“…We reduce the images using MultiDrizzle 12 with charge transfer inefficiency taken into account (e.g., Anderson & Bedin 2010;Massey et al 2010). The images are drizzled to a final pixel scale of 0.…”

Section: Archival Hst Imagingmentioning

confidence: 99%

Two Accurate Time-Delay Distances From Strong Lensing: Implications for Cosmology

Suyu

Auger

Hilbert

et al. 2013

ApJ

379

553

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Strong gravitational lenses with measured time delays between the multiple images and models of the lens mass distribution allow a one-step determination of the time-delay distance, and thus a measure of cosmological parameters. We present a blind analysis of the gravitational lens RXJ1131−1231 incorporating (1) the newly measured time delays from COSMOGRAIL, the COSmological MOnitoring of GRAvItational Lenses, (2) archival Hubble Space Telescope imaging of the lens system, (3) a new velocity-dispersion measurement of the lens galaxy of 323 ± 20 km s −1 based on Keck spectroscopy, and (4) a characterization of the line-of-sight structures via observations of the lens' environment and ray tracing through the Millennium Simulation. Our blind analysis is designed to prevent experimenter bias. The joint analysis of the data sets allows a time-delay distance measurement to 6% precision that takes into account all known systematic uncertainties. Time-delay lenses constrain especially tightly the Hubble constant H 0 (5.7% and 4.0% respectively in wCDM and open ΛCDM) and curvature of the universe. The overall information content is similar to that of Baryon Acoustic Oscillation experiments. Thus, they complement well other cosmological probes, and provide an independent check of unknown systematics. Our measurement of the Hubble constant is completely independent of those based on the local distance ladder method, providing an important consistency check of the standard cosmological model and of general relativity.

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Section: Archival Hst Imagingmentioning

confidence: 99%

Two Accurate Time-Delay Distances From Strong Lensing: Implications for Cosmology

Suyu

Auger

Hilbert

et al. 2013

ApJ

379

553

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“…When the image of an object is transferred across such a defect during parallel read-out, a fraction of its charge is trapped and statistically released, effectively creating charge-trails following objects in the read-out y-direction (e.g. Rhodes et al 2007;Chiaberge et al 2009;Massey et al 2010). For weak lensing measurements the dominant effect of CTI is the introduction of a spurious ellipticity component in the read-out direction.…”

Section: Weak Lensing Shape Measurementsmentioning

confidence: 99%

“…We present details on our CTI correction schemes for stars in Appendix B.4 and for galaxies in Appendix B.6. Note that Massey et al (2010) recently presented a method to correct for CTI directly on the image level. We find that the methods employed here are sufficient for our science analysis, as also confirmed by the tests presented in Sect.…”

Section: Weak Lensing Shape Measurementsmentioning

confidence: 99%

“…Internal calibrations (Mutchler & Sirianni 2005), photometric studies (e.g. Chiaberge et al 2009), as well as the analysis of warm pixels (Massey et al 2010) and cosmic rays (Jee et al 2009) demonstrate that the influence of CTI increases linearly with time and the number of y-transfers, where the latter has also been shown for the influence on galaxy ellipticities by Rhodes et al (2007). In addition, the limited depth of charge traps leads to a stronger influence of CTI for faint sources, which lose a larger fraction of their charge than bright sources.…”

Section: B4 Stellar Cti Correctionmentioning

confidence: 99%

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Evidence of the accelerated expansion of the Universe from weak lensing tomography with COSMOS

Schrabback

Hartlap

Joachimi

et al. 2010

A&A

346

457

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We present a comprehensive analysis of weak gravitational lensing by large-scale structure in the Hubble Space Telescope Cosmic Evolution Survey (COSMOS), in which we combine space-based galaxy shape measurements with ground-based photometric redshifts to study the redshift dependence of the lensing signal and constrain cosmological parameters. After applying our weak lensingoptimized data reduction, principal-component interpolation for the spatially, and temporally varying ACS point-spread function, and improved modelling of charge-transfer inefficiency, we measured a lensing signal that is consistent with pure gravitational modes and no significant shape systematics. We carefully estimated the statistical uncertainty from simulated COSMOS-like fields obtained from ray-tracing through the Millennium Simulation, including the full non-Gaussian sampling variance. We tested our lensing pipeline on simulated space-based data, recalibrated non-linear power spectrum corrections using the ray-tracing analysis, employed photometric redshift information to reduce potential contamination by intrinsic galaxy alignments, and marginalized over systematic uncertainties. We find that the weak lensing signal scales with redshift as expected from general relativity for a concordance ΛCDM cosmology, including the full cross-correlations between different redshift bins. Assuming a flat ΛCDM cosmology, we measure σ 8 (Ω m /0.3) 0.51 = 0.75 ± 0.08 from lensing, in perfect agreement with WMAP-5, yielding joint constraints Ω m = 0.266 +0.025 −0.023 , σ 8 = 0.802 +0.028 −0.029 (all 68.3% conf.). Dropping the assumption of flatness and using priors from the HST Key Project and Big-Bang nucleosynthesis only, we find a negative deceleration parameter q 0 at 94.3% confidence from the tomographic lensing analysis, providing independent evidence of the accelerated expansion of the Universe. For a flat wCDM cosmology and prior w ∈ [−2, 0], we obtain w < −0.41 (90% conf.). Our dark energy constraints are still relatively weak solely due to the limited area of COSMOS. However, they provide an important demonstration of the usefulness of tomographic weak lensing measurements from space.

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“…Updates to the procedure and the shear catalog are described in detail elsewhere in Leauthaud et al (2012). These improvements include a more detailed correction of charge transfer inefficiency from Massey et al (2010) and an empirical derivation of the dispersion in shear measurements in bins of magnitude and detection significance. This estimate of the shear dispersion includes contributions from intrinsic shape noise and shape measurement uncertainties and varies from σ γ ≈ 0.25 for bright galaxies to σ γ ≈ 0.40 for faint objects.…”

Section: Weak Lensing Datamentioning

confidence: 99%

Galaxies in X-Ray Groups. Ii. A Weak Lensing Study of Halo Centering

George

Leauthaud

Bundy

et al. 2012

ApJ

Self Cite

143

129

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Locating the centers of dark matter halos is critical for understanding the mass profiles of halos, as well as the formation and evolution of the massive galaxies that they host. The task is observationally challenging because we cannot observe halos directly, and tracers such as bright galaxies or X-ray emission from hot plasma are imperfect. In this paper, we quantify the consequences of miscentering on the weak lensing signal from a sample of 129 X-rayselected galaxy groups in the COSMOS field with redshifts 0 < z < 1 and halo masses in the range 10 13 -10 14 M . By measuring the stacked lensing signal around eight different candidate centers (such as the brightest member galaxy, the mean position of all member galaxies, or the X-ray centroid), we determine which candidates best trace the center of mass in halos. In this sample of groups, we find that massive galaxies near the X-ray centroids trace the center of mass to 75 kpc, while the X-ray position and centroids based on the mean position of member galaxies have larger offsets primarily due to the statistical uncertainties in their positions (typically ∼50-150 kpc). Approximately 30% of groups in our sample have ambiguous centers with multiple bright or massive galaxies, and some of these groups show disturbed mass profiles that are not well fit by standard models, suggesting that they are merging systems. We find that halo mass estimates from stacked weak lensing can be biased low by 5%-30% if inaccurate centers are used and the issue of miscentering is not addressed.

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Pixel-based correction for Charge Transfer Inefficiency in theHubble Space TelescopeAdvanced Camera for Surveys

Cited by 168 publications

References 29 publications

Two Accurate Time-Delay Distances From Strong Lensing: Implications for Cosmology

Two Accurate Time-Delay Distances From Strong Lensing: Implications for Cosmology

Evidence of the accelerated expansion of the Universe from weak lensing tomography with COSMOS

Galaxies in X-Ray Groups. Ii. A Weak Lensing Study of Halo Centering

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