We present a measurement of the temperature-polarization angular cross power spectrum, , of the Cosmic Microwave Background. The result is based on \(\sim 200\) hours of data from 8 polarization ...sensitive bolometers operating at 145 GHz during the 2003 flight of BOOMERANG. We detect a significant correlation in the \(\ell\)-range between 50 and 950 with a statistical significance > 3.5 sigma. Contamination by polarized foreground emission and systematic effects are negligible in comparison with statistical uncertainty. The spectrum is consistent with previous detections and with the "concordance model" that assumes adiabatic initial conditions. This is the first measurement of using bolometric detectors.
We report on observations of the Cosmic Microwave Background (CMB) obtained during the January 2003 flight of Boomerang . These results are derived from 195 hours of observation with four 145 GHz ...Polarization Sensitive Bolometer (PSB) pairs, identical in design to the four 143 GHz Planck HFI polarized pixels. The data include 75 hours of observations distributed over 1.84% of the sky with an additional 120 hours concentrated on the central portion of the field, itself representing 0.22% of the full sky. From these data we derive an estimate of the angular power spectrum of temperature fluctuations of the CMB in 24 bands over the multipole range (50 < l < 1500). A series of features, consistent with those expected from acoustic oscillations in the primordial photon-baryon fluid, are clearly evident in the power spectrum, as is the exponential damping of power on scales smaller than the photon mean free path at the epoch of last scattering (l > 900). As a consistency check, the collaboration has performed two fully independent analyses of the time ordered data, which are found to be in excellent agreement.
Astrophys.J. 571 (2002) 604-614 This paper presents a measurement of the angular power spectrum of the Cosmic
Microwave Background from l=75 to l=1025 (~10' to 5 degrees) from a combined
analysis of ...four 150 GHz channels in the BOOMERANG experiment. The spectrum
contains multiple peaks and minima, as predicted by standard
adiabatic-inflationary models in which the primordial plasma undergoes acoustic
oscillations. These results significantly constrain the values of Omega_tot,
Omega_b h^2, Omega_c h^2 and n_s.
We have made measurements of the Sunyaev-Zel'dovich (SZ) effect in six galaxy clusters at z > 0.2 using the Sunyaev-Zel'dovich Infrared Experiment (SuZIE II) in three frequency bands between 150 and ...350 GHz. Simultaneous multi-frequency measurements have been used to distinguish between thermal and kinematic components of the SZ effect, and to significantly reduce the effects of variations in atmospheric emission which can otherwise dominate the noise. We have set limits to the peculiar velocities of each cluster with respect to the Hubble flow, and have used the cluster sample to set a 95% confidence limit of < 1410 km/s to the bulk flow of the intermediate-redshift universe in the direction of the CMB dipole. This is the first time that SZ measurements have been used to constrain bulk flows. We show that systematic uncertainties in peculiar velocity determinations from the SZ effect are likely to be dominated by submillimeter point sources and we discuss the level of this contamination.
Prog.Part.Nucl.Phys.48:243-261,2002 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.
NewAstron.Rev.43:289-296,1999 We describe the BOOMERanG experiment, a stratospheric balloon telescope
intended to measure the Cosmic Microwave Background anisotropy at angular
scales between a few ...degrees and ten arcminutes. The experiment has been
optimized for a long duration (7 to 14 days) flight circumnavigating Antarctica
at the end of 1998. A test flight was performed on Aug.30, 1997 in Texas. The
level of performance achieved in the test flight was satisfactory and
compatible with the requirements for the long duration flight.
Astrophys.J. 536 (2000) L63-L66 We use the angular power spectrum of the Cosmic Microwave Background,
measured during the North American test flight of the BOOMERANG experiment, to
constrain the ...geometry of the universe. Within the class of Cold Dark Matter
models, we find that the overall fractional energy density of the universe,
Omega, is constrained to be 0.85 < Omega < 1.25 at the 68% confidence level.
Combined with the COBE measurement and the high redshift supernovae data we
obtain new constraints on the fractional matter density and the cosmological
constant.
The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB) radiation maps have detected ellipticity of the temperature anisotropy spots independent on the temperature threshold. The ...effect has been found for spots up to several degrees in size, where the biases of the ellipticity estimator and of the noise are small. To check the effect, now we have studied, with the same algorithm and in the same sky region, the WMAP maps. We find ellipticity of the same average value also in WMAP maps, despite of the different sensitivity of the two experiments to low multipoles. Large spot elongations had been detected also for the COBE-DMR maps. If this effect is due to geodesic mixing and hence due to non precisely zero curvature of the hyperbolic Universe, it can be linked to the origin of WMAP low multipoles anomaly.
We present the BOOMERanG-03 experiment and maps of the Stokes parameters I, Q, U of the microwave sky obtained during a 14 day balloon flight in 2003. Three regions of the southern sky were surveyed: ...a deep survey (~ 90 square degrees) and a shallow survey (~ 750 square degrees) at high Galactic latitudes (both centered at RA ~ 5.5 h, dec ~ -45 deg) and a survey of ~ 300 square degrees across the Galactic plane at RA ~ 9.1 h, dec ~ -47 deg. All three surveys were carried out in three wide frequency bands centered at 145, 245 and 345 GHz, with an angular resolution of ~ 10'. The 145 GHz maps of Stokes I are dominated by Cosmic Microwave Background (CMB) temperature anisotropy, which is mapped with high signal to noise ratio. The measured anisotropy pattern is consistent with the pattern measured in the same region by BOOMERanG-98 and by WMAP. The 145 GHz maps of Stokes Q and U provide a robust statistical detection of polarization of the CMB when subjected to a power spectrum analysis. This amplitude of the polarization is consistent with that of the CMB in the \(\Lambda\)CDM cosmological scenario. At 145 GHz, in the CMB surveys, the intensity and polarization of the astrophysical foregrounds are found to be negligible with respect to the cosmological signal. At 245 and 345 GHz we detect ISD emission correlated to the 3000 GHz IRAS/DIRBE maps, and give upper limits for any other non-CMB component. We also present intensity maps of the surveyed section of the Galactic plane. These are compared to monitors of different interstellar components, showing that a variety of emission mechanisms is present in that region.
We have measured the ellipticity of several degree scale anisotropies in the BOOMERanG maps of the Cosmic Microwave Background (CMB) at 150 GHz. The average ellipticity is around 2.6-2.7. The biases ...of the estimator of the ellipticity and for the noise are small in this case. Large spot elongation had been detected also for COBE-DMR maps. If this effect is due to geodesic mixing, it would indicate a non precisely zero curvature of the Universe which is among the discussed reasons of the WMAP low multipole anomaly. Both effects are related to the diameter of the Universe: the geodesics mixing through hyperbolic geometry, low multipoles through boundary conditions.This common reason can also be related with the origin of the the cosmological constant: the modes of vacuum fluctuations conditioned by the boundary conditions lead to a value of the cosmological constant being in remarkable agreement with the supernovae observations.
