Day 1388

Monday.

1803.08564
The WFIRST Exoplanet microlensing survey
Bennett, et al

WFIRST was the top ranked large space mission in the 2010 New Worlds, New Horizons decadal survey, and it was formed by merging the science programs of 3 different mission concepts, including the Microlensing Planet Finder (MPF) concept (Bennett+2010).  The WFIRST science program (Spergel+2015) consists of a general observer program, a wavefront controlled technology program, and two targeted science programs: a program to study dark energy, and a statistical census of exoplanets with a microlensing survey, which uses nearly one quarter of WFIRST's observing time in the current design reference mission.  The New Worlds, New Horizons (decadal survey) midterm assessment summarizes the science case for the WFIRST exoplanet microlensing survey with this statement: "WFIRST's microlensing census of planets beyond 1AU will perfectly complement Kepler's census of combat systems, and WFIRST will also be able to detect free-floating planets unbound from their parent stars."


1803.08717
Weak lensing by voids n weak lensing maps
Davies, et al

Cosmic voids are an important probe of LSS that allows us to constrain cosmological parameters and test cosmo models.  Present a new paradigm for void studies: void detection in WL convergence maps.  This approach identifies objects that relate directly to the theoretical understanding of voids as under densities in the total matter field and presents several advantages compared to the customary method of finding voids in the galaxy distribution.  Exemplify this approach by identifying voids using the WL peaks as tracers of the LSS.  Find self-similarity in the void abundance across a range of peak S/N selection thresholds.  The voids obtained via this approach give a tangential shear signal up to ~50 times larger than voids identified in the galaxy distribution.


1803.08682
A comprehensive understanding of planet formation is required for assessing planetary habitability and for the search for life
Apai, et al

Dozens of habitable zone, approximately earth-sized exoplanets are known today.  An emerging frontier of exoplanet studies is identifying which of these habitable zone, small planets are actually habitable (have all necessary conditions for life) and, of those, which are earth-like.  Many parameters and processes influence habitability, ranging from the orbit through detailed composition including volatiles and organics, to the presence of biological activity and plate tectonics.  While some properties will soon be directly observable, others cannot be probed by remote sensing for the foreseeable future.  Thus, statistical understanding of planetary systems' formation and evolution is a key supplement to the direct measurements of planet properties.  Probabilistically assessing parameters we cannot directly measure is essential to reliably assess habitability, to prioritizing habitable-zone planets for follow-up, and for interpreting possible bio signatures.