Fakultät für Physik und Astronomie
STEPHEN PHILLIPS hostreviews.co.uk / UNSPLASH

Intrinsically aligned galaxies in weak lensing data

Björn Malte Schäfer , ZAH, ITA Heidelberg

In gravitational lensing one commonly assumes that the intrinsic shapes of galaxies are uncorrelated and that any correlation in the shapes is due to correlated distortion in the weak lensing mapping: But in fact there are tidal interaction mechanisms that can make galaxy shapes intrinsically correlated. In my presentation I will discuss possible tidal interaction and alignment mechanisms for spiral and elliptical galaxies, how the details of the tidal interaction mechanism generates shape correlations as their signature, and how this contribution affects the measurement of cosmological parameters from gravitational lensing. Changing the perspective I will quantify how much about alignment and tidal interaction mechanisms can be learned from weak lensing data and how the two effects can be statistically separated. Finally, I will discuss the role of tidal interaction in the formation of haloes and how tidal interaction changes the mass distribution of haloes.

Heidelberg Joint Astronomical Colloquium
25 Apr 2017, 16:15
Philosophenweg 12, großer Hörsaal

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