Day 14

Lazy Saturday abstract reading blog.  So lazy, that I'm doing it on Sunday.

http://arxiv.org/abs/1106.1640

Using galaxy-galaxy weak lensing measurements to correct the Finger-of-God

Hikage, Takada, Spergel

* That's interesting.  How can one correct for FoG with halo mass measurements?

Estimate amplitude of FoG effect from gg WL measurements.  FoG suppresses power spectrum amplitudes: 30% at k=0.2 h/Mpc.  Need to complement spectroscopic survey with imaging survey with sufficient depth and area coverage, for unbiased use of power spectrum info: improves growth rate f = dlnD/dlna by factor of 2 for z<1.4.  w0 and m_nu can also be constrained without bias by combining lensing info (10--25% improvement).

* I guess it's done by generating FoG estimates from WL data.

http://arxiv.org/abs/1106.1765

Stellar streams as probes of dark halo mass ad morphology: a Bayesian reconstruction

Varghese, Ibata, Lewis

* Sound like a new method.

Use Parallel Tempering method (Bayesian/MCMC improvement) to fit streams to possible orbits of progenitor, in the absence of kinematic info.  Constrains shape of host halo and density distribution, assuming axisymmetry.  Add kinematic data to circular velocity curve of the host allows recovery of mass and profile.  Tested; in some cases additional data required.