Day 743

Friday.

1409.3238
The clustering of the SDSS main galaxy sample II: mock galaxy catalogue and a measurement of the growth of structure from redshift space distortions at $z=0.15$
Howlett, Ross, Samushia, Percival, Manera

Measure RSD in 2pt correlation function of 63k spec-z galaxies with z<0.2, an epoch where there are currently only limited measurements from SDSS7 Main sample.  This sample, denoted MGS, covers 6k sq deg with z_eff=0.15 which concentrates on BAO measurements.  In order to validate the fitting methods and derive errors, create and analyze 1000 mock catalogues using a new algorithm called PICOLA to generate accurate DM fields.  Haloes are then selected using a FoF algorithm, and populated with galaxies using HOD fitted to the data.  Fit a model to the monopole and quadrupole moments of the MGS correlation function, including both the RSD and AP effect, the latter of which results in anisotropic distortions if the wrong distance-redshift relation is used.  This gives a measurement of f(z_eff) sigma8(z_eff)=0.53pm0.19.  Assuming a fixed fiducial cosmology for the distance-z relationship based on recent Planck results, constraints on the growth rate tighten to f(z_eff) sigma8(z_eff)=0.44pm0.1.  Combine measurement with recent CMB and BAO data allows constraint on the growth index of fluctuations, gamma.  Assuming a BG LCDM cosmology, find gamma = 0.64pm0.09, which is consistent with the prediction of GR (gamma~0.55), though with a slight preference for higher gamma and hence models with weaker gravitational interactions.

1409.3242
The clustering of the SDSS DR7 Main Galaxy sample I: a 4 per cent distance measure at z=0.15
Ross, Samushia, Howlett, Percival, Burden, Manera

Create a sample of z<0.2 spec-z galaxies from SDSS DR7, covering 6813 sq deg.  Galaxies are chosen to sample the highest mass haloes, with an effective bias of 1.5, allowing construction of 1000 mock galaxy catalogs, which is used to estimate statistical errors and test methods.  Use an estimate of the gravitational potential to "reconstruct" the linear density fluctuations, enhancing BAO signal in the measured correlation function band PS.  Fitting to these measurements, determine D(z_eff=0.15)=644pm25(rd/rd_fid) Mpc, this s a better than 4% distance measurement.  This "fills the gap" in BAO distance ladder between previously measured local and higher z measurements, and affords significant improvement in constraining the properties of DE.  Combining measurement with other BAO measurements from BOSS and 6dFGS galaxy samples provides a 15% improvement n the determination of the EoS of DE and the value of the Hubble parameter at z=0 (H0).  Our measurement is fully consistent with the Planck results and the LCDM concordance cosmology, but increases the tension between Planck+BAO H0 determinations and direct H0 measurements.

1409.3364
Cosmological parameter constraints from CMB lensing with cosmic voids
Chantavat, Sawangwit, Sutter, Wandelt

Detecting a series of ~10 voids of size RV>20 Mpc/h along a LoS with 100-200 independent sq deg patches of the sky can potentially constrain cosmo parameters that are competitive with PLANCK alone.  The chance of finding such patches are seemingly small.  This analysis is based on current knowledge of the average void profiles and analytical estimates of the void number function in upcoming surveys.  The full potential of this technique relies on an accurate determination of the void profile to ~10% level.  CMB lensing with voids will provide a competitive and complimentary rout to parameter constraints for the next generation cosmo observations.  

1409.3409
CosmoSIS: modula cosmological parameter estimation
Zuntz et al

Present a new framework for cosmo parameter estimation, CosmoSIS, designed to connect together, share, and advance development of inference tools across the community.  Describe the modules already available in CosmoSIS, including CAMB, Planck, cosmic shear calculations, and a suite of samplers.  

1409.3528
Gender-based systematics in HST proposal selection
Reid

Proposal success rates calculated for HST cycles 11 through 21 as a function of gender of the PI.  In each cycle, proposals with male PIs have a higher success rate, with the disparity greatest for Cycles 12 and 18.  The offsets are small enough that they might be ascribed to chance for any single cycle, but the consistent pattern suggests the presence of a systematic effect.  Closer inspection of results from Cycles 19, 20 and 21 shows that the systematic difference does not appear to depend on the geographic origin of the proposal nor does it depend on the gender distribution on the review panels.  Segregating proposals by the seniority of the PI, the success rates by gender for more recent graduates (Phd since 2000) are more closely comparable.  There is also a correlation between success by gender and the average seniority of the review panel for Cycles 19, 20 but not 21.  Discuss these results and some consequent changes to the proposal format and additions to the HST TAC orientation process.