Estimation of halo ellipticity using spin-3 flexion

• Verfasst von: Er, Xinzhong [VerfasserIn]
• Verfasst von: Bartelmann, Matthias [VerfasserIn]
• Titel: Estimation of halo ellipticity using spin-3 flexion
• Verf.angabe: Xinzhong Er, Matthias Bartelmann
• Fussnoten: Gesehen am 21.09.2017
• Titel Quelle: Enthalten in: De.arxiv.org
• Jahr Quelle: 2012
• Band/Heft Quelle: (2012) Artikel-Nummer 1209.3072, 6 Seiten
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1563689383

Abstract

Estimating the ellipticity of dark matter haloes at the galaxy or galaxy-cluster scale can provide important constraints on the formation of galaxies or clusters, as well as on the nature of dark matter. We show in this paper that the spin-3 gravitational flexion can add useful information on the ellipticity of lensing haloes. We introduce a general formalism to decompose fields with arbitrary spin into radial and tangential components. The ratio of the tangential and radial flexion components directly estimates the lens ellipticity. We point out that any centroid offset will significantly bias our estimate, which on the other hand can be used to determine the centre of the lens halo.