Browsing by Author "Juin, J. B."

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    Precision cosmology with a wide area XMM cluster survey
    (2011) Pierre, M.; Pacaud, F.; Juin, J. B.; Melin, J. B.; Valageas, P.; Clerc, N.; Corasaniti, P. S.
    We explore the cosmological constraints expected from wide area XMM-type cluster surveys covering 50-200 deg(2), under realistic observing conditions. We perform a Fisher matrix analysis, based on cluster number counts in combination with estimates of the two-point cluster correlation function. The effect of the survey design is implemented through an observationally well-tested cluster selection function. Special attention is given to the modelling of the shot noise and sample variance, which we estimate by applying our selection function to numerically simulated surveys. We then infer the constraints on the equation of state of the dark energy, considering various survey configurations. We quantitatively investigate the respective impact of the cluster mass measurements, of the correlation function and of the 1 < z < 2 cluster population. We show that, with some 20 Ms XMM observing time, it is possible to constrain the dark energy parameters at a level comparable to that expected from the next generation of cosmic probes. Such a survey also has the power to provide unique insights into the physics of high-redshift clusters and the properties of active galactic nuclei.
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    The Atacama Cosmology Telescope (ACT): Beam Profiles and First SZ Cluster Maps
    (2010) Hincks, A. D.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.; Burger, B.; Chervenak, J.; Das, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dunkley, J.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Hajian, A.; Halpern, M.; Hasselfield, M.; Hernández-Monteagudo, C.; Hilton, G. C.; Hilton, M.; Hlozek, R.; Huffenberger, K. M.; Hughes, D. H.; Hughes, J. P.; Infante, L.; Irwin, K. D.; Jimenez, R.; Juin, J. B.; Kaul, M.; Klein, J.; Kosowsky, A.; Lau, J. M.; Limon, M.; Lin, Y. -T.; Lupton, R. H.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Menanteau, F.; Moodley, K.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Partridge, B.; Quintana, H.; Reid, B.; Sehgal, N.; Sievers, J.; Spergel, D. N.; Staggs, S. T.; Stryzak, O.; Swetz, D. S.; Switzer, E. R.; Thornton, R.; Trac, H.; Tucker, C.; Verde, L.; Warne, R.; Wilson, G.; Wollack, E.; Zhao, Y.
    The Atacama Cosmology Telescope (ACT) is currently observing the cosmic microwave background with arcminute resolution at 148 GHz, 218 GHz, and 277 GHz. In this paper, we present ACT's first results. Data have been analyzed using a maximum-likelihood map-making method which uses B-splines to model and remove the atmospheric signal. It has been used to make high-precision beam maps from which we determine the experiment's window functions. This beam information directly impacts all subsequent analyses of the data. We also used the method to map a sample of galaxy clusters via the Sunyaev-Zel'dovich (SZ) effect and show five clusters previously detected with X-ray or SZ observations. We provide integrated Compton-y measurements for each cluster. Of particular interest is our detection of the z = 0.44 component of A3128 and our current non-detection of the low-redshift part, providing strong evidence that the further cluster is more massive as suggested by X-ray measurements. This is a compelling example of the redshift-independent mass selection of the SZ effect.
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    THE ATACAMA COSMOLOGY TELESCOPE: A MEASUREMENT OF THE 600 < ℓ < 8000 COSMIC MICROWAVE BACKGROUND POWER SPECTRUM AT 148 GHz
    (2010) Fowler, J. W.; Acquaviva, V.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.; Burger, B.; Chervenak, J.; Das, S.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dunkley, J.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Hajian, A.; Halpern, M.; Hasselfield, M.; Hernández-Monteagudo, C.; Hilton, G. C.; Hilton, M.; Hincks, A. D.; Hlozek, R.; Huffenberger, K. M.; Hughes, D. H.; Hughes, J. P.; Infante, L.; Irwin, K. D.; Jimenez, R.; Juin, J. B.; Kaul, M.; Klein, J.; Kosowsky, A.; Lau, J. M.; Limon, M.; Lin, Y. -T.; Lupton, R. H.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Menanteau, F.; Moodley, K.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Partridge, B.; Quintana, H.; Reid, B.; Sehgal, N.; Sievers, J.; Spergel, D. N.; Staggs, S. T.; Swetz, D. S.; Switzer, E. R.; Thornton, R.; Trac, H.; Tucker, C.; Verde, L.; Warne, R.; Wilson, G.; Wollack, E.; Zhao, Y.
    We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1'.4 angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg(2) of the southern sky, in a 4 degrees.2 wide strip centered on declination 53 degrees south. The CMB at arcminute angular scales is particularly sensitive to the Silk damping scale, to the Sunyaev-Zel'dovich (SZ) effect from galaxy clusters, and to emission by radio sources and dusty galaxies. After masking the 108 brightest point sources in our maps, we estimate the power spectrum between 600 < l < 8000 using the adaptive multi-taper method to minimize spectral leakage and maximize use of the full data set. Our absolute calibration is based on observations of Uranus. To verify the calibration and test the fidelity of our map at large angular scales, we cross-correlate the ACT map to the WMAP map and recover the WMAP power spectrum from 250 < l < 1150. The power beyond the Silk damping tail of the CMB (l similar to 5000) is consistent with models of the emission from point sources. We quantify the contribution of SZ clusters to the power spectrum by fitting to a model normalized to sigma(8) = 0.8. We constrain the model's amplitude A(SZ) < 1.63 (95% CL). If interpreted as a measurement of sigma(8), this implies sigma(SZ)(8) < 0.86 (95% CL) given our SZ model. A fit of ACT and WMAP five-year data jointly to a six-parameter Lambda CDM model plus point sources and the SZ effect is consistent with these results.