Probing Galaxy Dark Matter Haloes in COSMOS with Weak Lensing Flexion - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Probing Galaxy Dark Matter Haloes in COSMOS with Weak Lensing Flexion - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Current theories of structure formation predict specific density profiles ofgalaxy dark matter haloes, and with weak gravitational lensing we can probethese profiles on several scales. On small scales, higher-order shapedistortions known as flexion add significant detail to the weak lensingmeasurements. We present here the first detection of a galaxy-galaxy flexionsignal in space-based data, obtained using a new Shapelets pipeline introducedhere. We combine this higher-order lensing signal with shear to constrain theaverage density profile of the galaxy lenses in the Hubble Space TelescopeCOSMOS survey. We also show that light from nearby bright objects cansignificantly affect flexion measurements. After correcting for the influenceof lens light, we show that the inclusion of flexion provides tighterconstraints on density profiles than does shear alone. Finally we find anaverage density profile consistent with an isothermal sphere.



Author: Malin Velander, Konrad Kuijken, Tim Schrabback

Source: https://arxiv.org/







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