Day 833

Friday.

1502.03442
Disentangling dark sector models using weak lensing statistics
Giocoli, Metcalf, .. Meneghetti, ... et al

Perofrm multi-plen ray-tracing using GLAMER GL code within high-res light-cones extracted from CoDECS sims: a suite of cosmo runs featuring a coupling between DE and CDM.  Show that the presence of the coupling is evident not only in the z evolution of the normalization of the convergence PS, but also in differences in NL structure formation wrt LCDM.  Using a tomographic approach under the assumption of LCDM cosmology, demonstrate that WL measurements would result in a sigma8 value that changes with the source z if the true underlying cosmology is a coupled DE one.  This provides a generic null test for these types of models.  Also find that different models of coupled DE can show either an enhanced or a suppressed correlation between convergence maps with differing source z as compared to LCDM.  This would provide a direct way to discriminate between different possible realisations of the coupled DE scenario.  Finally, discuss the impact of the coupling on several lensing observables for different source z and angular scales with realistic source z distributions for current ground-based and future space-based lensing surveys.

1502.03545
Catalog of visually classified galaxies in the local ($z\sim0.01$) universe
Ann, Seo, Ha

The morphological types of 5840 galaxies were classified by visual inspection of color images using SDSS DR7 to produce a morphology catalog of a representative sample of local galaxies with z<0.01.  The sample galaxies are almost complete for galaxies brighter than r_pet=17.77.  The classification system is basically the same as that of the Third Reference Catalog of Bright Galaxies with some simplification for giant galaxies.  On the other hand, fine features of dwarf elliptical-like galaxies are distinguished to classify 5 sub-types: dwarf ellipticals (dE), blue-cored dwarf ellipticals (dE_bc), dwarf spheroidals (dSph), blue dwarf elliptical (dE_blue), and dwarf lenticulars (dS0).  In addition, denote the presence of nucleation in dE, dSph, and dS0.  Elliptical galaxies and lenticular galaxies contribute only ~1.5% and 4.9% of the local galaxies, respectively, whereas spirals and irregulars contribute ~32.1% and ~42.8%, respectively.  The dE_blue galaxies, which are recently found populations of galaxies, contribute a significant fraction to the dwarf galaxies.  There seems to be structural difference between dSph and dE galaxies.  The dSph galaxies are fainter and bluer with shallower surface brightness garden than dE galaxies.  They also have lower fraction of galaxies with small axis ratios (b/a<~0.4) than dE galaxies.  The mean projected distances to the nearest neighbor galaxy is ~260kpc.  About 1% of local galaxies have no neighbors with comparable luminosity within a projected distance of 2Mpc.

1502.03795
Correcting the z~8 galaxy luminosity function for gravitational lensing magnification bias
Mason, Treu, ... Marshall, et al

Present a Bayesian framework to account for the magnification bias from both SL and WL in estimates of high-z galaxy LFs.  Illustrate the method by estimating the z~8 UV LF using a sample of 97 Y-band dropouts (Lyman-break galaxies) found in the Brightest of Reionizing Galaxies (BoRG) survey and from the literature.  Find the LF is well described by a Schechter function with characteristic magnitude of M*=-19.8, faint-end slope of alpha=-1.7, and number density of log10 Psi*[Mpc^-3] = -3.0.  These parameters are consistent within the uncertainties with those inferred from the same sample without accounting for the magnification bias demonstrating that the effect is small for current surveys at z~8, and cannot account for the apparent over density of bright galaxies found recently.  Estimate that the probability of finding a strongly lensed z~8 source in the sample is in the range ~3-15% depending on limiting magnitude.  Identify one strongly-lensed candidate and 3 cases of intermediate lensing in BoRG (estimated magnification mu>1.4) in addition to the previously known candidate group-scale strong lens.  Using a range of theoretical LFs, conclude that magnification bias will dominate wide field surveys (e.g., Euclid and WFIRST), especially at z>10.  Magnification bias will need to be accounted for in order to derive accurate estimates of high-z LFs in these surveys and to distinguish between galaxy formation models.