Shapelets “Multiple Multipole” Shear Measurement
نویسندگان
چکیده
منابع مشابه
Shapelets Multiple Multipole Shear Measurement
The measurement of weak gravitational lensing is currently limited to a precision of ∼10% by instabilities in galaxy shape measurement techniques and uncertainties in their calibration. The potential of large, on-going and future cosmic shear surveys will only be realised with the development of more accurate image analysis methods. We present a description of several possible shear measurement...
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We derive expressions, in terms of ‘polar shapelets’, for the image distortion operations associated with weak gravitational lensing. Shear causes galaxy shapes to become elongated, and is sensitive to the second derivative of the projected gravitational potential along their line of sight; flexion bends galaxy shapes into arcs, and is sensitive to the third derivative. Polar shapelets provide ...
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The gravitational lensing equations for convergence, potential, shear, and flexion are simple in polar coordinates and separate under a multipole expansion once the shear and flexion spinors are rotated into a “tangential” basis. We use this to investigate whether the useful monopole aperture-mass shear formulae generalize to all multipoles and to flexions. We re-derive the result of Schneider ...
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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2004
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921305001766