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1.
Phys Rev Lett ; 127(15): 151301, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34678017

RESUMO

We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to and including the 2018 observing season. We add additional Keck Array observations at 220 GHz and BICEP3 observations at 95 GHz to the previous 95/150/220 GHz dataset. The Q/U maps now reach depths of 2.8, 2.8, and 8.8 µK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈600 square degrees at 95 GHz and ≈400 square degrees at 150 and 220 GHz. The 220 GHz maps now achieve a signal-to-noise ratio on polarized dust emission exceeding that of Planck at 353 GHz. We take auto- and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz and evaluate the joint likelihood of the spectra versus a multicomponent model of lensed ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and no longer requires a prior on the frequency spectral index of the dust emission taken from measurements on other regions of the sky. This model is an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.036 at 95% confidence. Running maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.009. These are the strongest constraints to date on primordial gravitational waves.

2.
Phys Rev Lett ; 121(22): 221301, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30547645

RESUMO

We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including the 2015 observing season. This includes the first Keck Array observations at 220 GHz and additional observations at 95 and 150 GHz. The Q and U maps reach depths of 5.2, 2.9, and 26 µK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈400 square degrees. The 220 GHz maps achieve a signal to noise on polarized dust emission approximately equal to that of Planck at 353 GHz. We take auto and cross spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz. We evaluate the joint likelihood of the spectra versus a multicomponent model of lensed-ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and we impose priors on some of these using external information from Planck and WMAP derived from larger regions of sky. The model is shown to be an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.07 at 95% confidence, which tightens to r_{0.05}<0.06 in conjunction with Planck temperature measurements and other data. The lensing signal is detected at 8.8σ significance. Running a maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.020. These are the strongest constraints to date on primordial gravitational waves.

3.
Phys Rev Lett ; 116(3): 031302, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26849583

RESUMO

We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to and including the 2014 observing season. This includes the first Keck Array observations at 95 GHz. The maps reach a depth of 50 nK deg in Stokes Q and U in the 150 GHz band and 127 nK deg in the 95 GHz band. We take auto- and cross-spectra between these maps and publicly available maps from WMAP and Planck at frequencies from 23 to 353 GHz. An excess over lensed ΛCDM is detected at modest significance in the 95×150 BB spectrum, and is consistent with the dust contribution expected from our previous work. No significant evidence for synchrotron emission is found in spectra such as 23×95, or for correlation between the dust and synchrotron sky patterns in spectra such as 23×353. We take the likelihood of all the spectra for a multicomponent model including lensed ΛCDM, dust, synchrotron, and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r) using priors on the frequency spectral behaviors of dust and synchrotron emission from previous analyses of WMAP and Planck data in other regions of the sky. This analysis yields an upper limit r_{0.05}<0.09 at 95% confidence, which is robust to variations explored in analysis and priors. Combining these B-mode results with the (more model-dependent) constraints from Planck analysis of CMB temperature plus baryon acoustic oscillations and other data yields a combined limit r_{0.05}<0.07 at 95% confidence. These are the strongest constraints to date on inflationary gravitational waves.

4.
Phys Rev Lett ; 114(10): 101301, 2015 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-25815919

RESUMO

We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 µK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

5.
Phys Rev Lett ; 112(24): 241101, 2014 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-24996078

RESUMO

We report results from the BICEP2 experiment, a cosmic microwave background (CMB) polarimeter specifically designed to search for the signal of inflationary gravitational waves in the B-mode power spectrum around ℓ∼80. The telescope comprised a 26 cm aperture all-cold refracting optical system equipped with a focal plane of 512 antenna coupled transition edge sensor 150 GHz bolometers each with temperature sensitivity of ≈300 µK(CMB)√s. BICEP2 observed from the South Pole for three seasons from 2010 to 2012. A low-foreground region of sky with an effective area of 380 square deg was observed to a depth of 87 nK deg in Stokes Q and U. In this paper we describe the observations, data reduction, maps, simulations, and results. We find an excess of B-mode power over the base lensed-ΛCDM expectation in the range 30 < ℓ < 150, inconsistent with the null hypothesis at a significance of >5σ. Through jackknife tests and simulations based on detailed calibration measurements we show that systematic contamination is much smaller than the observed excess. Cross correlating against WMAP 23 GHz maps we find that Galactic synchrotron makes a negligible contribution to the observed signal. We also examine a number of available models of polarized dust emission and find that at their default parameter values they predict power ∼(5-10)× smaller than the observed excess signal (with no significant cross-correlation with our maps). However, these models are not sufficiently constrained by external public data to exclude the possibility of dust emission bright enough to explain the entire excess signal. Cross correlating BICEP2 against 100 GHz maps from the BICEP1 experiment, the excess signal is confirmed with 3σ significance and its spectral index is found to be consistent with that of the CMB, disfavoring dust at 1.7σ. The observed B-mode power spectrum is well fit by a lensed-ΛCDM+tensor theoretical model with tensor-to-scalar ratio r = 0.20_(-0.05)(+0.07), with r = 0 disfavored at 7.0σ. Accounting for the contribution of foreground, dust will shift this value downward by an amount which will be better constrained with upcoming data sets.

6.
Phys Rev Lett ; 111(14): 141301, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-24138230

RESUMO

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

7.
Nature ; 495(7441): 344-7, 2013 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-23485967

RESUMO

In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

8.
Mund Kiefer Gesichtschir ; 7(6): 356-60, 2003 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-14648252

RESUMO

AIM: The temporomandibular function of patients after orthognathic surgery was evaluated with the Helkimo index (D 0-III) and compared with a normal population. PATIENTS AND METHODS: Temporomandibular disorders (TMD) were evaluated with the Helkimo index (D 0-III) in a group of patients (n=105, F=69, M=36) after osteotomies. The average follow-up time was 47 months (9-141 months). The osteotomies performed were as follows: 58 bilateral sagittal split osteotomies, 12 Le Fort I osteotomies, 22 bimaxillary osteotomies, and 13 segment-osteotomies. A control group (n=202, F=114, M=88, age 20-39 years) was examined in an epidemiological study. The statistical analysis was performed using Windows software SPSS 10.0. RESULT: In 82.8% of the patients no symptoms or mild dysfunction were found. The comparison between the patient group (31.4%) and the control group (31.7%) revealed a similar frequency. The most frequent dysfunction was a reduced mobility of the mandible, which determined the statistical significance (p<0,05) between the patients and the control group for the dysfunction group D II and D III. The chi-square test could not detect any difference between sex and the kind of osteotomy with regard to dysfunction.


Assuntos
Má Oclusão/cirurgia , Mandíbula/cirurgia , Maxila/cirurgia , Ortodontia Corretiva , Osteotomia de Le Fort , Osteotomia , Complicações Pós-Operatórias/epidemiologia , Síndrome da Disfunção da Articulação Temporomandibular/epidemiologia , Adulto , Estudos Transversais , Feminino , Seguimentos , Alemanha/epidemiologia , Humanos , Incidência , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Valores de Referência , Síndrome da Disfunção da Articulação Temporomandibular/diagnóstico , Síndrome da Disfunção da Articulação Temporomandibular/etiologia
9.
Mund Kiefer Gesichtschir ; 6(1): 15-8, 2002 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-11974540

RESUMO

BACKGROUND: The aim of the study was to analyze the influence of possible temporary or permanent disorders of sensation on the degree of the patient's satisfaction following an orthognathic operation. PATIENTS AND METHODS: After an average of 47 months (range: 9-141), a follow-up examination was performed in 78 women (64.5%) and 43 men (35.5%) with an average age of 24.3 years (range: 19-40) at the time of operation. In 67 cases there had been a sagittal division of the mandible, in 11 cases a Le Fort I osteotomy, in 26 cases a bimaxillary osteotomy, in 4 cases an isolated genioplasty, and in 13 cases a segmental osteotomy in the upper or the lower jaw. In the peripheral area supplied by the nerves V2 and V3 sensation was examined by the two-point discrimination test and the result related to the patients' satisfaction using the chi-square test. RESULTS AND DISCUSSION: The following qualities of sensation were recorded: anesthetic (2.7%), hypesthetic (16.6%), paresthetic (8.3%), and normesthetic (72.4%). The patients' satisfaction was rated as very satisfied in 51.3%, as satisfactory in 44.8%, and in 3.9% the patients' expectations had not been fulfilled; 75% regarded their outward appearance as markedly improved and a good 50% of the patients noted improved mastication. Therefore, three-fourths of all the patients would even be willing to be operated on again. Two-dimensional analysis, however, demonstrated only a weakly significant positive relationship between patient satisfaction and the preserved, or restored, sensation in the trigeminal region.


Assuntos
Estética , Má Oclusão/cirurgia , Satisfação do Paciente , Complicações Pós-Operatórias/psicologia , Cirurgia Bucal/psicologia , Adulto , Feminino , Humanos , Hiperestesia/psicologia , Masculino , Má Oclusão/psicologia , Parestesia/psicologia , Resultado do Tratamento
10.
Phys Rev Lett ; 86(16): 3475-9, 2001 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-11328002

RESUMO

Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE DMR, provide consistent and high signal-to-noise measurements of the cosmic microwave background power spectrum at spherical harmonic multipole bands over 2

11.
Appl Opt ; 40(28): 4921-32, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18364768

RESUMO

We present the design and performance of a feedhorn-coupled bolometer array intended for a sensitive 350-mum photometer camera. Silicon nitride micromesh absorbers minimize the suspended mass and heat capacity of the bolometers. The temperature transducers, neutron-transmutation-doped Ge thermistors, are attached to the absorber with In bump bonds. Vapor-deposited electrical leads address the thermistors and determine the thermal conductance of the bolometers. The bolometer array demonstrates a dark noise-equivalent power of 2.9 x 10(-17) W/ radicalHz and a mean heat capacity of 1.3 pJ/K at 390 mK. We measure the optical efficiency of the bolometer and feedhorn to be 0.45-0.65 by comparing the response to blackbody calibration sources. The bolometer array demonstrates theoretical noise performance arising from the photon and the phonon and Johnson noise, with photon noise dominant under the design background conditions. We measure the ratio of total noise to photon noise to be 1.21 under an absorbed optical power of 2.4 pW. Excess noise is negligible for audio frequencies as low as 30 mHz. We summarize the trade-offs between bare and feedhorn-coupled detectors and discuss the estimated performance limits of micromesh bolometers. The bolometer array demonstrates the sensitivity required for photon noise-limited performance from a spaceborne, passively cooled telescope.

12.
Appl Opt ; 36(4): 765-71, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18250736

RESUMO

We report the design and performance of 300-mK composite bolometers that use micromesh absorbers and support structures patterned from thin films of low-stress silicon nitride. The small geometrical filling factor of the micromesh absorber provides 20x reduction in heat capacity and cosmic ray cross section relative to a solid absorber with no loss in IR-absorption efficiency. The support structure is mechanically robust and has a thermal conductance, G < 2 x 10(-11) W/K, which is four times smaller than previously achieved at 300 mK. The temperature rise of the bolometer is measured with a neutron transmutation doped germanium thermistor attached to the absorbing mesh. The dispersion in electrical and thermal parameters of a sample of 12 bolometers optimized for the Sunyaev-Zel'dovich Infrared Experiment is +/-7% in R (T), +/-5% in optical efficiency, and +/-4% in G.

13.
Appl Opt ; 34(13): 2268-77, 1995 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-21037777

RESUMO

We report the design and testing of a compact system of baffles for cooled infrared telescopes. The baffle system consists of a reflecting forebaffle and a black aftbaffle and provides a high level of rejection of emission from off-axis sources. The forebaffle reflects radiation incident at angles greater than 40° off axis out of the telescope, thereby reducing the aperture heat load. The black aftbaffle absorbs radiation scattered or diffracted by the forebaffle, as well as radiation from sources within 40° off axis. We describe ground-based measurements at λ = 0.9 µm of the baffle system at ambient temperature and rocketborne measurements at far-infrared wavelengths of the baffle system at ~3 K. The effective emissivity of the cooled forebaffle was measured to be 7 × 10(-3). The system has been successfully used in rocketborne measurements of the diffuse infrared background and will be used in the Infrared Telescope in Space.

14.
Appl Opt ; 34(19): 3651-7, 1995 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21052183

RESUMO

We developed a far-infrared Fabry-Perot filter constructed from a single silicon substrate. The limiting resolving power caused by beam divergence of a silicon-gap Fabry-Perot filter is approximately 10 times higher than that of a vacuum-gap Fabry-Perot filter because of the large index of refraction of silicon. The filter thus permits compact, high-throughput optical systems. Metal mesh patterns microlithographed on each face provide enhanced, wavelength-dependent face reflectivity. We tested the performance of filters with metal mesh patterns consisting of inductive crosses and capacitive squares. A Fabry-Perot filter developed for a rocketborne astrophysics experiment with a capacitive square metal mesh pattern achieves a resolving power of λ/Δλ(FWHM) =160 at λ= 158 µm, with a peak transmittance of 37% over an active aperture of 6.9 mm for an ƒ/3.8 optical beam at 15° incidence. The absorptivity of a 240-µm thick silicon substrate patterned with capacitive metal mesh is A ≲ 1% per pass, including loss in both the silicon and the metal mesh.

15.
Appl Opt ; 34(22): 4812-6, 1995 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21052320

RESUMO

We have developed an instrument for directly measuring the emissivity of reflective surfaces at near-millimeter wavelengths. The thermal emission of a test sample is compared with that of a reference surface, allowing the emissivity of the sample to be determined without heating. The emissivity of the reference surface is determined by one's heating the reference surface and measuring the increase in emission. The instrument has an absolute accuracy of Δε = 5 × 10(-4) and can reproducibly measure a difference in emissivity as small as Δε = 10(-4) between flat reflective samples. We have used the instrument to measure the emissivity of metal films evaporated on glass and carbon fiber-reinforced plastic composite surfaces. We measure an emissivity of (2.15 ± 0.4) × 10(-3) for gold evaporated on glass and (2.65 ± 0.5) × 10(-3) for aluminum evaporated on carbon fiber-reinforced plastic composite.

16.
Appl Opt ; 34(31): 7254-7, 1995 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21060592

RESUMO

We describe a low-pass filter that provides high in-band transmittance and excellent rejection at ν > 100 cm(-1). The transmittance of the filter components was measured at liquid-helium temperatures from 10 to 10,000 cm(-1). The total transmittance is >50% for ν < 50 cm(-1) and is calculated to be <10(-9) for ν > 300 cm(-1). The filter was successfully used in a liquid-helium-cooled, rocketborne, far-infrared absolute photometer.

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