Towards a cosmological neutrino mass detection
Physical Review D American Physical Society 92:12 (2015) ARTN 123535
Abstract:Future cosmological measurements should enable the sum of neutrino masses to be determined indirectly through their effects on the expansion rate of the Universe and the clustering of matter. We consider prospects for the gravitationally lensed cosmic microwave background (CMB) anisotropies and baryon acoustic oscillations (BAOs) in the galaxy distribution, examining how the projected uncertainty of ≈15 meV on the neutrino mass sum (a 4σ detection of the minimal mass) might be reached over the next decade. The current 1σ uncertainty of ≈103 meV (Planck-2015 þ BAO-15) will be improved by upcoming “Stage-3” (S3) CMB experiments (S3 þ BAO-15∶ 44 meV), then upcoming BAO measurements (S3 þ DESI∶ 22 meV), and planned next-generation “Stage 4” (S4) CMB experiments (S4 þ DESI∶ 15–19 meV, depending on angular range). An improved optical depth measurement is important: the projected neutrino mass uncertainty increases to 26 meV if S4 is limited to l > 20 and combined with current large-scale polarization data. Looking beyond ΛCDM, including curvature uncertainty increases the forecast mass error by ≈50% for S4 þ DESI, and more than doubles the error with a two-parameter dark-energy equation of state. Complementary low-redshift probes including galaxy lensing will play a role in distinguishing between massive neutrinos and a departure from a w ¼ −1, flat geometry.
THE ATACAMA COSMOLOGY TELESCOPE: LENSING OF CMB TEMPERATURE AND POLARIZATION DERIVED FROM COSMIC INFRARED BACKGROUND CROSS-CORRELATION
ASTROPHYSICAL JOURNAL 808:1 (2015) ARTN 7
The Atacama Cosmology Telescope: measuring radio galaxy bias through cross-correlation with lensing
Monthly Notices of the Royal Astronomical Society Oxford University Press 451:1 (2015) 849-858
Abstract:© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. We correlate the positions of radio galaxies in the FIRST survey with the cosmic microwave background lensing convergence estimated from the Atacama Cosmology Telescope over 470 deg < sup > 2 < /sup > to determine the bias of these galaxies. We remove optically cross-matched sources below redshift z = 0.2 to preferentially select active galactic nuclei (AGN). We measure the angular cross-power spectrum C < inf > l < /inf > < sup > kg < /sup > at 4.4σ significance in the multipole range 100 < l < 3000, corresponding to physical scales within ≈2-60 Mpc at an effective redshift z < inf > eff < /inf > = 1.5. Modelling the AGN population with a redshift-dependent bias, the cross-spectrum is well fitted by the Planck best-fitting Λ cold dark matter cosmological model. Fixing the cosmology and assumed redshift distribution of sources, we fit for the overall bias model normalization, finding b(z < inf > eff < /inf > ) = 3.5 ± 0.8 for the full galaxy sample and b(z < inf > eff < /inf > ) = 4.0 ± 1.1(3.0 ± 1.1) for sources brighter (fainter) than 2.5 mJy. This measurement characterizes the typical halo mass of radio-loud AGN: we find log(M < inf > halo < /inf > /M < inf > ⊙ < /inf > ) = 13.6 < inf > -0.4 < /inf > < sup > +0.3 < /sup > .
Evidence of lensing of the cosmic microwave background by dark matter halos.
Physical review letters 114:15 (2015) 151302
Abstract:We present evidence of the gravitational lensing of the cosmic microwave background by 10(13) solar mass dark matter halos. Lensing convergence maps from the Atacama Cosmology Telescope Polarimeter (ACTPol) are stacked at the positions of around 12 000 optically selected CMASS galaxies from the SDSS-III/BOSS survey. The mean lensing signal is consistent with simulated dark matter halo profiles and is favored over a null signal at 3.2σ significance. This result demonstrates the potential of microwave background lensing to probe the dark matter distribution in galaxy group and galaxy cluster halos.
Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust
ASTRONOMY & ASTROPHYSICS 576 (2015) ARTN A104