Cluster Cosmology

h1. Journal Club

*Time:* Weekly - Friday, 14:00 - 15:30

*Place:* Seminar room - I13 - upstairs

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h2. Next paper - *11.01.12* 

h3. The Atacama Cosmology Telescope: Sunyaev-Zel'dovich Selected Galaxy Clusters at 148 GHz from Three Seasons of Data

Matthew Hasselfield, Matt Hilton, Tobias A. Marriage, Graeme E. Addison, L. Felipe Barrientos, Nick Battaglia, Elia S. Battistelli, J. Richard Bond, Devin Crichton, Sudeep Das, Mark J. Devlin, Simon R. Dicker, Joanna Dunkley, Rolando Dunner, Joseph W. Fowler, Megan B. Gralla, Amir Hajian, Mark Halpern, Adam D. Hincks, Renée Hlozek, John P. Hughes, Leopoldo Infante, Kent D. Irwin, Arthur Kosowsky, Danica Marsden, Felipe Menanteau, Kavilan Moodley, Michael D. Niemack, Michael R. Nolta, Lyman A. Page, Bruce Partridge, Erik D. Reese, Benjamin L. Schmitt, Neelima Sehgal, Blake D. Sherwin, Jon Sievers, Cristóbal Sifón, David N. Spergel, Suzanne T. Staggs, Daniel S. Swetz, Eric R. Switzer, Robert Thornton, Hy Trac, Edward J. Wollack

(Submitted on 4 Jan 2013)

[Abridged] We present a catalog of 68 galaxy clusters, of which 19 are new discoveries, detected via the Sunyaev-Zel'dovich effect (SZ) at 148 GHz in the Atacama Cosmology Telescope (ACT) survey of 504 square degrees on the celestial equator. A subsample of 48 clusters within the 270 square degree region overlapping SDSS Stripe 82 is estimated to be 90% complete for M_500c > 4.5e14 Msun and 0.15 < z < 0.8. While matched filters are used to detect the clusters, the sample is studied further through a "Profile Based Amplitude Analysis" using a single filter at a fixed \theta_500 = 5.9' angular scale. This new approach takes advantage of the "Universal Pressure Profile" (UPP) to break the degeneracy between the cluster extent (R_500) and the integrated Compton parameter (Y_500). The UPP scalings are found to be nearly identical to an adiabatic model, while a model incorporating non-thermal pressure better matches dynamical mass measurements and masses from the South Pole Telescope. A complete, high signal to noise ratio subsample of 15 ACT clusters is used to obtain cosmological constraints. We first confirm that constraints from SZ data are limited by uncertainty in the scaling relation parameters rather than sample size or measurement uncertainty. We next add in seven clusters from the ACT Southern survey, including their dynamical mass measurements based on galaxy velocity dispersions. In combination with WMAP7 these data simultaneously constrain the scaling relation and cosmological parameters, yielding \sigma_8 = 0.829 \pm 0.024 and \Omega_m = 0.292 \pm 0.025. The results include marginalization over a 15% bias in dynamical mass relative to the true halo mass. In an extension to LCDM that incorporates non-zero neutrino mass density, we combine our data with WMAP7+BAO+Hubble constant measurements to constrain \Sigma m_\nu < 0.29 eV (95% C. L.).

http://arXiv.org/abs/1301.0816

h3. The Atacama Cosmology Telescope: Cosmological parameters from three seasons of data

Jonathan L. Sievers, Renée A. Hlozek, Michael R. Nolta, Viviana Acquaviva, Graeme E. Addison, Peter A. R. Ade, Paula Aguirre, Mandana Amiri, John William Appel, L. Felipe Barrientos, Elia S. Battistelli, Nick Battaglia, J. Richard Bond, Ben Brown, Bryce Burger, Erminia Calabrese, Jay Chervenak, Devin Crichton, Sudeep Das, Mark J. Devlin, Simon R. Dicker, W. Bertrand Doriese, Joanna Dunkley, Rolando Dünner, Thomas Essinger-Hileman, David Faber, Ryan P. Fisher, Joseph W. Fowler, Patricio Gallardo, Michael S. Gordon, Megan B. Gralla, Amir Hajian, Mark Halpern, Matthew Hasselfield, Carlos Hernández-Monteagudo, J. Colin Hill, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Dave Holtz, Kevin M. Huffenberger, David H. Hughes, John P. Hughes, Leopoldo Infante, Kent D. Irwin, David R. Jacobson, et al. (47 additional authors not shown)

(Submitted on 4 Jan 2013)

We present constraints on cosmological and astrophysical parameters from high-resolution microwave background maps at 148 GHz and 218 GHz made by the Atacama Cosmology Telescope (ACT) in three seasons of observations from 2008 to 2010. A model of primary cosmological and secondary foreground parameters is fit to the map power spectra and lensing deflection power spectrum, including contributions from both the thermal and kinematic Sunyaev-Zeldovich (SZ) effect, Poisson and correlated anisotropy from unresolved infrared sources, radio sources, and the correlation between the thermal SZ effect and infrared sources. The power ell^2 C_ell/2pi of the thermal SZ power spectrum at 148 GHz is measured to be 3.4 + /-1.4 muK^2 at ell=3000, while the corresponding amplitude of the kinematic SZ power spectrum has a 95 percent confidence level upper limit of 8.6 muK^2. Combining ACT power spectra with the WMAP 7-year temperature and polarization power spectra, we find excellent consistency with the LCDM model. We constrain the number of effective relativistic degrees of freedom in the early universe to be Neff=2.78 + / -  0.55, in agreement with the canonical value of Neff=3.046 for three massless neutrinos. We constrain the sum of the neutrino masses to be Sigma m_nu < 0.39 eV at 95% confidence when combining ACT and WMAP 7-year data with BAO and Hubble constant measurements. We constrain the amount of primordial helium to be Yp = 0.226 + / - 0.032, and measure no variation in the fine structure constant alpha since recombination, with alpha/alpha_0 = 1.004+/- 0.005. We also find no evidence for any running of the scalar spectral index, dns/dln k = - 0.003 +/- 0.013.

http://arXiv.org/abs/1301.0824

h3. The Atacama Cosmology Telescope: the stellar content of galaxy clusters selected using the Sunyaev-Zel'dovich effect

http://arXiv.org/abs/1301.0780

h3. The Atacama Cosmology Telescope: likelihood for small-scale CMB data

http://arXiv.org/abs/1301.0776

h2. Paper pool

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h2. Video talks and lectures

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h2. Previous papers

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