LANL Abstracts: BOOMERanG experient, Universe curvature, local fluctuations

From: Amara Graps (amara@amara.com)
Date: Sun Jan 13 2002 - 08:15:37 MST


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Astrophysics, abstract
astro-ph/0201137

From: Silvia Masi <silvia.masi@roma1.infn.it>
Date: Wed, 9 Jan 2002 19:27:28 GMT (315kb)

The BOOMERanG experiment and the curvature of the Universe

Authors: S. Masi, P.A.R. Ade, J.J. Bock, J.R. Bond, J. Borrill, A.
Boscaleri, K. Coble, C.R. Contaldi, B.P. Crill, P. de Bernardis, G. De
Gasperis, G. De Troia, P. Farese, K. Ganga, M. Giacometti, E. Hivon, V.V.
Hristov, A. Iacoangeli, A.H. Jaffe, W.C. Jones, A.E. Lange, L. Martinis, P.
Mason, P.D. Mauskopf, A. Melchiorri, P. Natoli, T. Montroy, C.B.
Netterfield, E. Pascale, F. Piacentini, D. Pogosyan, G. Polenta, F.
Pongetti, S. Prunet, G. Romeo, J.E. Ruhl, F. Scaramuzzi, N. Vittorio
Comments: Proc. of the Erice School on "Neutrinos in Astro, Particle and
Nuclear Physics", 18.-26. September 2001, Amand Faessler, Jan Kuckei eds,
"Progress in Particle and Nuclear Physics", vol. 48

     We describe the BOOMERanG experiment and its main result, i.e. the
     measurement of the large scale curvature of the Universe.
     BOOMERanG is a balloon-borne microwave telescope with sensitive
     cryogenic detectors. BOOMERanG has measured the angular
     distribution of the Cosmic Microwave Background on $\sim 3%$ of
     the sky, with a resolution of $\sim 10$ arcmin and a sensitivity
     of $\sim 20 \mu K$ per pixel. The resulting image is dominated by
     hot and cold spots with rms fluctuations $\sim 80 \mu K$ and
     typical size of $\sim 1^o$. The detailed angular power spectrum of
     the image features three peaks and two dips at $\ell =
     (213^{+10}_{-13}), (541^{+20}_{-32}), (845^{+12}_{-25})$ and $\ell
     = (416^{+22}_{-12}), (750^{+20}_{-750})$, respectively. Such very
     characteristic spectrum can be explained assuming that the
     detected structures are the result of acoustic oscillations in the
     primeval plasma. In this framework, the measured pattern
     constrains the density parameter $\Omega$ to be $0.85 < \Omega <
     1.1$ (95% confidence interval). Other cosmological parameters,
     like the spectral index of initial density fluctuations, the
     density parameter for baryons, dark matter and dark energy, are
     detected or constrained by the BOOMERanG measurements and by other
     recent CMB anisotropy experiments. When combined with other
     cosmological observations, these results depict a new, consistent,
     cosmological scenario.

Paper: PostScript, PDF, or Other formats

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Astrophysics, abstract
astro-ph/0201133

From: Gianluca Polenta <gianluca.polenta@roma1.infn.it>
Date: Wed, 9 Jan 2002 17:49:29 GMT (188kb)

Search for non-gaussian signals in the BOOMERanG maps: pixel-space analysis

Authors: G. Polenta, P.A.R. Ade, J.J. Bock, J.R. Bond, J. Borrill, A.
Boscaleri, C.R. Contaldi, B.P. Crill, P. de Bernardis, G. De Gasperis, G. De
Troia, K. Ganga, M. Giacometti, E. Hivon, V.V. Hristov, A.H. Jaffe, A.E.
Lange, S. Masi, P.D. Mauskopf, A. Melchiorri, T. Montroy, P. Natoli, C.B.
Netterfield, E. Pascale, F. Piacentini, D. Pogosyan, S. Prunet, G. Romeo,
J.E. Ruhl, N. Vittorio, A.Zeppilli
Comments: submitted to Ap.J. Letters

     We search the BOOMERanG maps of the anisotropy of the Cosmic
     Microwave Background (CMB) for deviations from gaussianity. In
     this paper we focus on analysis techniques in pixel-space, and
     compute skewness, kurtosis and Minkowski functionals for the
     BOOMERanG maps and for gaussian simulations of the CMB sky. We do
     not find any significant deviation from gaussianity in the high
     galactic latitude section of the 150 GHz map. We do find
     deviations from gaussianity at lower latitudes and at 410 GHz, and
     we ascribe them to Galactic dust contamination. Using non-gaussian
     simulations of instrumental systematic effects, of foregrounds,
     and of sample non-gaussian cosmological models, we set upper
     limits to the non-gaussian component of the temperature field in
     the BOOMERanG maps. For fluctuations distributed as a 1 DOF
     $\chi^2$ mixed to the main gaussian component our upper limits are
     in the few % range.

Paper: PostScript, PDF, or Other formats

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Amara Graps, PhD | Max-Planck-Institut fuer Kernphysik
Heidelberg Cosmic Dust Group | Saupfercheckweg 1
+49-6221-516-543 | 69117 Heidelberg, GERMANY
Amara.Graps@mpi-hd.mpg.de * http://www.mpi-hd.mpg.de/dustgroup/~graps
************************************************************************
"We came whirling out of Nothingness scattering stars like dust." --Rumi



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