Day 97

Monday (holiday, Germany Unity Day).  Had dinner with Aaron last night.


1109.2592
Lensing time delays and cosmological complementarity
Linder


Time delay in SL complements distance measurements to determine w, Omega_m and H0.  Time delays useful when observations allow detailed lens modeling and variability studies; requires high resolution imaging, long time monitoring and rapid cadence.  For 150 time delay lenses with good observation with SNe program such as DES, adding time delay to data to SNe, CMB can improve DE FoM by almost a factor 5 and determine the matter density Omega_m to 0.004, h to 0.7%, and w_a to 0.26, without any systematics.


1109.2594
Combined strong and weak lensing analysis of 28 clusters from the Sloan Giant Arcs Survey
Oguri, Bayliss, Dahle, Sharon, Gladders, Natarajan, Hennawi, Koester


Combine Subaru WL with giant arc SL info to study mass distribution of 28 galaxy clusters.  Robust constraints on the concentration parameter and shape of the mass distribution.  Concentration c_vir is a steep function of the mass, c_vir \propto M_vir^-0.6, with the value roughly consistent with the lensing-bias-corrected theoretical expectation for high mass (1e15 M_sun/h) clusters.  The observationally inferred concentration parameters appear to be much higher at lower masses (1e14 M_sun/h), possibly a consequence of the modification to the inner density profiles from baryonic contraction.  Steep mass-concentration relation is also supported from direct stacking analysis of the tangential shear profiles.  In addition, explore two-dimensional shape of the projected mass distribution--find large mean ellipticity with the best-fit value of e=0.47 pm 0.06 for the mass distribution of the stacked sample (position angle determined from SL).  Luminous cluster member galaxy distribution traces the overall mass distribution well, although the distribution of fainter cluster galaxies appears to be more extended than the total mass.


* cool.


1109.2671
The dynamical state of DM haloes in cosmological simulations I:  Correlations with mass assembly history
Power, Knebe, Knollmann


Quantify impact of simulated halo's mass accretion and merging history on two commonly measures of its dynamical state: the virial ratio eta and the center of mass offset Delta r.  Important, because the degree to which a halo is dynamically equilibrated will influence the reliability with which we can measure characteristic equilibrium properties of the structure and kinematics of a population of haloes.  Halo's formation redshift z_form correlates with its virial mass M_vir; fraction of its recently accreted mass and the likelihood of it having experienced a recent major merger increases with increasing M_vir and decreasing z_form; implies massive recently formed haloes are more likely to be dynamically unrelaxed than their less massive ad older counterparts.  Both eta and Delta r are good indicators of a halo's dynamical state, showing strong positive correlations with recent mass accretion and merging activity; but Delta r provides a more robust and better defined measure of dynamical state for use in cosmological N-body simulations at z~0.  We find that Delta r < 0.04 is sufficient to pick out dynamically relaxed haloes at z=0.  Assess results in the context of previous studies, and consider observational implications.


1109.2732
Shape and orientation of the gas distribution in A1689
Sereno, Ettori, Baldi


Gas distribution modelled with an ellipsoidal parametric profile that fit observed X-ray surfac-brightness and temperature.  Comparison with the SZ amplitude fixes the elongation along the LOS.  Bayesian inference allows deprojection of the measured elongation and the projected ellipticity, and constrain the intrinsic shape and orientation of the cluster.  Apply method to the rich cluster A1689.  Observations cover in detail a region <1Mpc.  Analysis favors mildly triaxial cluster with a minor to major axis ratio of 0.70, preferentially elongated along the LoS, as expected for massive lensing clusters.  Triaxial structure together with the orientation bias can reconcile X-ray with lensing analysis and supports the view of A1689 as a just slightly over-concentrated massive cluster massive cluster not so far from hydrostatic equilibrium.


* cool.


1109.2790
Testing the cosmic distance duality with X-ray gas mass fraction and SNe data
Goncalves, Holanda, Alcaniz


Cosmic distance duality relation: eta = DL/(1+z)^2/DA should be = 1.  f_gas with SNeIa furnish a validity test for eta.  Use 38 f_gas measurements and two subsamples of SNeIa from Union2.  COnsider eta parameter as a function of redshift parameterized by two different functional forms.  LaRoque sample has eta=1, but Ettori conflicts (both f_gas measurements).


* how does f_gas affect distance duality relation?  using the epxression forX-ray gass mass fraction of galaxy clusters, f_gas \propto DL DA^{1/2}.


* interesting way to verify f_gas measurements.


1109.2846
Figure of merit and different combinations of observational data sets
Cai, Su, Tuo


Found two sets of combinations of observational methods that yield high FoM.


1109.1599
Missing the Point--a brief reply to Foreman & Scott and Gnedin
Stacy McGaugh


Foreman & Scott and Gnedin criticize baryonic TF relation of gas-rich galaxies as test of MOND and LCDM.  Sceptical of both LCDM and MOND.


1109.1609
Distribution function approach to redshift space distortions: N-body simulations
Okumura, Seljak, McDonald, Desjaques


RSD directly probes the cosmic growth history of density perturbations.  Distribution function approach: RSD written as sum over density weighted velocity moment correlators.  Use N-body sims to investigate the individual contributions and convergence of this expansion.  Expand as powers of mu, finite number of terms contributing at each order.  Present these terms and investigate their contribution to the total as a function of wavevector k.  mu^2: correlation between density and momentum dominates on large scales.  Higher order orrections (FoG term) contribute 1% at k~0.015h/Mpc, 10% at k~0.05h/Mpc (z-0), while for k>0.15h/Mpcthey dominate and make the total negative.  Higher order terms dominated by density-energy density correlations which contribute negatively to the power, while the contribution from vorticity part of momentum density auto-correlation, is an order of magnitude lower.  For mu^4 term the dominant term on large scales is the scalar part of momentum density auto-correlation, while higher order terms dominate for k>0.15h/Mpc.  For mu^6 and mu^8 we find it has very little power for k<0.15h/Mpc.  Compare expansion to the full 2D P^ss(k,mu) as well as to their multipoles.  An infinite number of terms contribute and the expansion achieves percent level accuracy for kmu < 0.15h/pc at 6th order, but breaks down on smaller scales because the series is no longer perturbative.  Explore resummation of the terms in to FoG kernels, which extend the convergence up to a factor of 2 on scale.  Find that the FoG kernels are approximately Lorentzian.  


1109.1743
The 2XMMi/SDSS galaxy cluster survey I. The first cluster sample and X-ray luminosity-temperature relation
Takey, Schwope, Lamer


Present catalogue of X-ray selected galaxy clusters and groups as a first release of the 2XMMi/SDSS galaxy cluster survey.  ID new X-ray galaxy clusters, investigate X-ray scaling relations, identify distant cluster candidates and study the correlation of the X-ray and optical properties.  Correlate XMM serendipitous source catalog with SDSS optical cluster, yield  photometric redshifts for 275 objects.  182 have at least one spectro data.  175 in initial catalog, 139 objects are new X-ray discoveries.  0.09<z<0.61.  L_500 = 1.9e42 to 1.2e45; M_500=2.3e13 to 4.9e14 M_sun.  Slope of the linear L-T relation is consistent with values published for high luminosities.


1109.1799
Recent results on the low mass DM WIMP controversy: 2011
Cline


Update of recent experimental results concerning evidence for low-mass WIMPs.  Not a critical comparison of the claims of various experimental groups.    "We have little to say about this situation except that the scientific method usually insures the correct results will eventually surface."


1109.1809
Directional limits on gravitational waves using LIGO S5 science data
Abbott, ........ 714 people total, et al


Find no evidence to support the detection of GWs, present 90% confidence leve lupper limit maps of GW strain power for pointlike and extended sources.