Day 838

Monday.

1502.05709
Test for radial mixing of stars in M31
Gould, Rix

Effective radial migration and mixing of orbits throughout the stellar disk has been definitely established in the MW, but not in any other galaxy.  Show how such radial mixing can be measured (or strongly constrained) in M31 using a combination of existing data and readily available facilities.

1502.05733
The observational status of cosmic inflation after Planck
Martin

These pedagogical lecture notes are intended to serve as a technical guide filling the gap between the theoretical articles on inflation and the experimental works on astrophysical and cosmological data.  After a short discussion of the central tenets at the basis of inflation (negative self-gravitating pressure)  and its experimental verifications, it reviews how the most recent CBM anisotropy measurements constrain cosmic inflation.  The fact that vanilla inflationary models are, so far, preferred by the observations is discussed and the reason why plateau-like potential versions of inflation are favored within this subclass of scenarios is explained.  Finally, how well the future measurements, in particular of B-mode CMB polarization or primordial gravity waves, will help to improve the knowledge about inflation is also investigated.

1502.05872
Weak lensing reconstructions in 2D & 3D: implications for cluster studies
Leonard, Lanusse, Starck

Compare the efficiency with which 2D and 3D weak lensing mass mapping techniques are able to detect clusters of galaxies using 2 state-of-the-art mass reconstruction techniques: MRLens in 2D and GLIMPSE in 3D.  Simulate otherwise-empty cluster fields for 96 different virial mass-redshift combinations spanning the ranges 3e13 Msun/h<M_vir<1e15 Msun/h and 0.05<z_cl<0.75, and for each generate 1000 realizations of noisy shear data in 2d and 3d.  For each field, compute the cluster (false) detection rate as the mean number of cluster (false) detections per reconstruction over the sample of 1000 reconstructions.  Show that both MRLens and GLIMPSE are effective tools for the detection of clusters from WL measurements, and provide comparable quality reconstructions at low redshift.  At high z, GLIMPSE reconstructions offer increased sensitivity in the detection of clusters, yielding cluster detection rates up to a factor of 10x that seen in 2d reconstructions using MRLens.  Conclude that 3d mass mapping techniques are more efficient for the detection of clusters of galaxies in WL surveys than 2d methods, particularly since 3d reconstructions yield unbiased estimators of both the mass and z of the detected clusters directly.