Intrinsic alignments: cosmology from the large scales & constraining the non-linear regime
Abstract
While intrinsic alignments are usually regarded as a contaminant of cosmic shear measurements, they encode cosmological information and information about the formation history of galaxies. In the first part of the talk, I will discuss the tidal alignment model, which has been shown to reproduce the intrinsic alignments of Luminous Red Galaxies on large scales. I will present prospects of using the intrinsic alignments of Luminous Red Galaxies as a probe of cosmology with ongoing and upcoming surveys. I will focus on baryon acoustic oscillations (BAO) and primordial non-Gaussianity. I will demostrate that the BAO signature can be detected in the correlation function of galaxies and their intrinsic shapes to high significance in upcoming spectroscopic surveys, such as DESI and Euclid. In the second part of the talk, I will focus on the alignment of galaxies in non-linear scales, within clusters of galaxies. I will describe a method to separate the intrinsic alignment of galaxies in the clusters from the lensing signal of galaxies behind the clusters using photometric redshift posterior distributions. Finally, I will present observational constraints on the intrinsic alignment of cluster galaxies in the Sloan Digital Sky Survey "Stripe 82", for clusters between redshifts 0.1<z<0.4, and discuss implications for upcoming weak gravitational lensing surveys.
- Publication:
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American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22342601C