Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-10T16:29:46.058Z Has data issue: false hasContentIssue false

Do Angular Momentum Induced Ellipticity Correlations Contaminate Weak Lensing Measurements?

Published online by Cambridge University Press:  05 March 2013

Priyamvada Natarajan
Affiliation:
Department of Astronomy, Yale University, New Haven, CT, USA; priya@astro.yale.edu
Robert G. Crittenden
Affiliation:
Department of Applied Mathematics and Theoretical Physics, Wilberforce Road, Cambridge CB3 0WA, UK; R.G.Crittenden@damtp.cam.ac.uk
Ue-Li Pen
Affiliation:
CITA, McLennan Labs, University of Toronto, Toronto, M5S 3H8, Canada; pen@cita.utoronto.ca
Tom Theuns
Affiliation:
Institute of Astronomy, Madingley Road, Cambridge CB3 0HE, UK; tt@ast.cam.ac.uk
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Alignments in the angular momentum vectors of galaxies can induce large scale correlations in their projected orientations. Such alignments arise from the tidal torques exerted on neighboring protogalaxies by the smoothly varying shear field. Weak gravitational lensing can also induce ellipticity correlations since the images of neighboring galaxies will be distorted coherently by the intervening mass distribution. Comparing these two sources of shape correlations, it is found that for current weak lensing surveys with a median redshift of zm = 1, the intrinsic signal is a contaminant on the order of 1–10% of the measured signal. However, for shallower surveys with zm ≤ 0.3, the intrinsic correlations dominate over the lensing signal. The distortions induced by lensing are curl-free, whereas those resulting from intrinsic alignments are not. This difference can be used to disentangle these two sources of ellipticity correlations. When the distortions are dominated by lensing, as occurs at high redshifts, the decomposition provides a valuable tool for understanding properties of the noise and systematic errors.

Type
Research Article
Copyright
Copyright © Astronomical Society of Australia 2001

References

Bacon, D., Refregier, A., & Ellis, R. S. 2000, MNRAS, 318, 625 Google Scholar
Bartelmann, M., & Schneider, P. 1999, Review for Physics Reports, preprint, astro-ph/9909155Google Scholar
Bernardeau, F., van Waerbeke, L., & Mellier, Y. 1997, A&A, 322, 1 Google Scholar
Blandford, R. D., Saust, A. B., Brainerd, T. G., & Villumsen, J. V. 1991, MNRAS, 251, 600 Google Scholar
Brown, M. L., Taylor, A. N., Hambly, N. C., & Dye, S. 2000, preprint, astro-ph/0009499Google Scholar
Crittenden, R., Natarajan, P., Pen, U., & Theuns, T. 2001a, ApJ submitted, astro-ph/0009052Google Scholar
Crittenden, R., Natarajan, P., Pen, U., & Theuns, T. 2001b, ApJ submitted, astro-ph/0012336Google Scholar
Gunn, J. 1967, ApJ, 150, 737 Google Scholar
Heavens, A., Refregier, A., & Heymans, C. 2000, MNRAS, 319, 649 Google Scholar
Jain, B., & Seljak, U. 1997, ApJ, 484, 560 Google Scholar
Jain, B., Seljak, U., & White, S. D. M. 2000, ApJ, 530, 547 CrossRefGoogle Scholar
Kaiser, N. 1992, APJ, 388, 272 Google Scholar
Kaiser, N. 1995, ApJL, 439L, 1 Google Scholar
Kaiser, N., Wilson, G., & Luppino, G. 2000, preprint, astro-ph/0003338Google Scholar
Lee, J., & Pen, U. 2000, ApJ, 532, L5 Google Scholar
Miralda-Escude, J. 1991, ApJ, 380, 1 Google Scholar
van Waerbeke, L., et al. 2000, A&A, 358, 30 Google Scholar
Wittman, D., Tyson, J. A., Kirkman, D., Dell'Antonio, I., & Bernstein, G. 2000, Nature, 405, 143 Google Scholar