# Browsing by Subject "space vehicles"

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Item Five-Year Wilkinson Microwave Anisotropy Probe Observations: Data Processing, Sky Maps, and Basic Results(2009-02) Hinshaw, G.; Weiland, J. L.; Hill, R. S.; Odegard, N.; Larson, D.; Bennett, C. L.; Dunkley, J.; Gold, B.; Greason, M. R.; Jarosik, N.; Komatsu, Eiichiro; Nolta, M. R.; Page, L.; Spergel, D. N.; Wollack, E.; Halpern, M.; Kogut, A.; Limon, M.; Meyer, S. S.; Tucker, G. S.; Wright, E. L.; Komatsu, EiichiroShow more We present new full-sky temperature and polarization maps in five frequency bands from 23 to 94 GHz, based on data from the first five years of the Wilkinson Microwave Anisotropy Probe (WMAP) sky survey. The new maps are consistent with previous maps and are more sensitive. The five-year maps incorporate several improvements in data processing made possible by the additional years of data and by a more complete analysis of the instrument calibration and in-flight beam response. We present several new tests for systematic errors in the polarization data and conclude that W-band polarization data is not yet suitable for cosmological studies, but we suggest directions for further study. We do find that Ka-band data is suitable for use; in conjunction with the additional years of data, the addition of Ka band to the previously used Q- and V-band channels significantly reduces the uncertainty in the optical depth parameter, tau. Further scientific results from the five-year data analysis are presented in six companion papers and are summarized in Section 7 of this paper. With the five-year WMAP data, we detect no convincing deviations from the minimal six-parameter Lambda CDM model: a flat universe dominated by a cosmological constant, with adiabatic and nearly scale-invariant Gaussian fluctuations. Using WMAP data combined with measurements of Type Ia supernovae and Baryon Acoustic Oscillations in the galaxy distribution, we find (68% CL uncertainties): Omega(b)h(2) = 0.02267(-0.00059)(+0.00058), Omega(c)h(2) = 0.1131 +/- 0.0034, Omega(Lambda) = 0.726 +/- 0.015, n(s) = 0.960 +/- 0.013, tau = 0.084 +/- 0.016, and Delta(2)(R) = (2.445 +/- 0.096) x 10(-9) at k = 0.002 Mpc(-1). From these we derive sigma(8) = 0.812 +/- 0.026, H(0) = 70.5 +/- 1.3 km s(-1) Mpc(-1), Omega(b) = 0.0456 +/- 0.0015, Omega(c) = 0.228 +/- 0.013, Omega(m)h(2) = 0.1358(-0.0036)(+0.0037), z(reion) = 10.9 +/- 1.4, and t(0) = 13.72 +/- 0.12 Gyr. The new limit on the tensor-to-scalar ratio is r < 0.22 (95% CL), while the evidence for a running spectral index is insignificant, dn(s)/d ln k = - 0.028 +/- 0.020 (68% CL). We obtain tight, simultaneous limits on the (constant) dark energy equation of state and the spatial curvature of the universe: - 0.14 < 1 + w < 0.12 (95% CL) and -0.0179 < Omega(k) < 0.0081 (95% CL). The number of relativistic degrees of freedom, expressed in units of the effective number of neutrino species, is found to be N(eff) = 4.4 +/- 1.5 (68% CL), consistent with the standard value of 3.04. Models with N(eff) = 0 are disfavored at >99.5% confidence. Finally, new limits on physically motivated primordial non-Gaussianity parameters are -9 < f(NL)(local) < 111 (95% CL) and -151 < f(NL)(equil) < 253 (95% CL) for the local and equilateral models, respectively.Show more Item Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results(2013-10) Hinshaw, G.; Larson, D.; Komatsu, Eiichiro; Spergel, D. N.; Bennett, C. L.; Dunkley, J.; Nolta, M. R.; Halpern, M.; Hill, R. S.; Odegard, N.; Page, L.; Smith, K. M.; Weiland, J. L.; Gold, B.; Jarosik, N.; Kogut, A.; Limon, M.; Meyer, S. S.; Tucker, G. S.; Wollack, E.; Wright, E. L.; Komatsu, EiichiroShow more We present cosmological parameter constraints based on the final nine-year Wilkinson Microwave Anisotropy Probe (WMAP) data, in conjunction with a number of additional cosmological data sets. The WMAP data alone, and in combination, continue to be remarkably well fit by a six-parameter Delta CDM model. When WMAP data are combined with measurements of the high-l cosmic microwave background anisotropy, the baryon acoustic oscillation scale, and the Hubble constant, the matter and energy densities, Omega(b)h(2), Omega(c)h(2), and Omega(Lambda), are each determined to a precision of similar to 1.5%. The amplitude of the primordial spectrum is measured to within 3%, and there is now evidence for a tilt in the primordial spectrum at the 5 sigma level, confirming the first detection of tilt based on the five-year WMAP data. At the end of the WMAP mission, the nine-year data decrease the allowable volume of the six-dimensional Delta CDM parameter space by a factor of 68,000 relative to pre-WMAP measurements. We investigate a number of data combinations and show that their Delta CDM parameter fits are consistent. New limits on deviations from the six-parameter model are presented, for example: the fractional contribution of tensor modes is limited to r < 0.13 (95% CL); the spatial curvature parameter is limited to Omega(k) = -0.0027(-0.0038)(+0.0039); the summed mass of neutrinos is limited to Sigma m(nu) < 0.44 eV (95% CL); and the number of relativistic species is found to lie within N-eff = 3.84 +/- 0.40, when the full data are analyzed. The joint constraint on N-eff and the primordial helium abundance, Y-He, agrees with the prediction of standard big bang nucleosynthesis. We compare recent Planck measurements of the Sunyaev-Zel'dovich effect with our seven-year measurements, and show their mutual agreement. Our analysis of the polarization pattern around temperature extrema is updated. This confirms a fundamental prediction of the standard cosmological model and provides a striking illustration of acoustic oscillations and adiabatic initial conditions in the early universe.Show more Item Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results(2013-10) Bennett, C. L.; Larson, D.; Weiland, J. L.; Jarosik, N.; Hinshaw, G.; Odegard, N.; Smith, K. M.; Hill, R. S.; Gold, B.; Halpern, M.; Komatsu, Eiichiro; Nolta, M. R.; Page, L.; Spergel, D. N.; Wollack, E.; Dunkley, J.; Kogut, A.; Limon, M.; Meyer, S. S.; Tucker, G. S.; Wright, E. L.; Komatsu, EiichiroShow more We present the final nine-year maps and basic results from the Wilkinson Microwave Anisotropy Probe (WMAP) mission. The full nine-year analysis of the time-ordered data provides updated characterizations and calibrations of the experiment. We also provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are examined to separate cosmic microwave background (CMB) anisotropy from foreground emission, and both types of signals are analyzed in detail. We provide new point source catalogs as well as new diffuse and point source foreground masks. An updated template-removal process is used for cosmological analysis; new foreground fits are performed, and new foreground reduced CMB maps are presented. We now implement an optimal C-1 weighting to compute the temperature angular power spectrum. The WMAP mission has resulted in a highly constrained Delta CDM cosmological model with precise and accurate parameters in agreement with a host of other cosmological measurements. When WMAP data are combined with finer scale CMB, baryon acoustic oscillation, and Hubble constant measurements, we find that big bang nucleosynthesis is well supported and there is no compelling evidence for a non-standard number of neutrino species (N-eff = 3.84 +/- 0.40). The model fit also implies that the age of the universe is t(0) = 13.772 +/- 0.059 Gyr, and the fit Hubble constant is H-0 = 69.32 +/- 0.80 km s(-1) Mpc(-1). Inflation is also supported: the fluctuations are adiabatic, with Gaussian random phases; the detection of a deviation of the scalar spectral index from unity, reported earlier by the WMAP team, now has high statistical significance (n(s) = 0.9608 +/- 0.0080); and the universe is close to flat/Euclidean (Omega(k) = -0.0027(-0.0038)(+0.0039)). Overall, the WMAP mission has resulted in a reduction of the cosmological parameter volume by a factor of 68,000 for the standard six-parameter Delta CDM model, based on CMB data alone. For a model including tensors, the allowed seven-parameter volume has been reduced by a factor 117,000. Other cosmological observations are in accord with the CMB predictions, and the combined data reduces the cosmological parameter volume even further. With no significant anomalies and an adequate goodness of fit, the inflationary flat Delta CDM model and its precise and accurate parameters rooted in WMAP data stands as the standard model of cosmology.Show more Item Planetary Candidates Observed By Kepler Iv: Planet Sample from Q1-Q8 (22 Months)(2014-02) Burke, Christopher J.; Bryson, Stephen T.; Mullally, F.; Rowe, Jason F.; Christiansen, Jessie L.; Thompson, Susan E.; Coughlin, Jeffrey L.; Haas, Michael R.; Batalha, Natalie M.; Caldwell, Douglas A.; Jenkins, Jon M.; Still, Martin; Barclay, Thomas; Borucki, William J.; Chaplin, William J.; Ciardi, David R.; Clarke, Bruce D.; Cochran, William D.; Demory, Brice-Olivier; Esquerdo, Gilbert A.; Gautier, Thomas N., III; Gilliland, Ronald L.; Girouard, Forrest R.; Havel, Mathieu; Henze, Christopher E.; Howell, Steve B.; Huber, Daniel; Latham, David W.; Li, Jie; Morehead, Robert C.; Morton, Timothy D.; Pepper, Joshua; Quintana, Elisa; Ragozzine, Darin; Seader, Shawn E.; Shah, Yash; Shporer, Avi; Tenenbaum, Peter; Twicken, Joseph D.; Wolfgang, Angie; Cochran, William D.Show more We provide updates to the Kepler planet candidate sample based upon nearly two years of high-precision photometry (i.e., Q1-Q8). From an initial list of nearly 13,400 threshold crossing events, 480 new host stars are identified from their flux time series as consistent with hosting transiting planets. Potential transit signals are subjected to further analysis using the pixel-level data, which allows background eclipsing binaries to be identified through small image position shifts during transit. We also re-evaluate Kepler Objects of Interest (KOIs) 1-1609, which were identified early in the mission, using substantially more data to test for background false positives and to find additional multiple systems. Combining the new and previous KOI samples, we provide updated parameters for 2738 Kepler planet candidates distributed across 2017 host stars. From the combined Kepler planet candidates, 472 are new from the Q1-Q8 data examined in this study. The new Kepler planet candidates represent similar to 40% of the sample with R-P similar to 1R(circle plus) and represent similar to 40% of the low equilibrium temperature (T-eq < 300 K) sample. We review the known biases in the current sample of Kepler planet candidates relevant to evaluating planet population statistics with the current Kepler planet candidate sample.Show more Item Planetary Candidates Observed by Kepler. III. Analysis of the First 16 Months of Data(2013-02) Batalha, Natalie M.; Rowe, Jason F.; Bryson, Stephen T.; Barclay, Thomas; Burke, Christopher J.; Caldwell, Douglas A.; Christiansen, Jessie L.; Mullally, Fergal; Thompson, Susan E.; Brown, Timothy M.; Dupree, Andrea K.; Fabrycky, Daniel C.; Ford, Eric B.; Fortney, Jonathan J.; Gilliland, Ronald L.; Isaacson, Howard; Latham, David W.; Marcy, Geoffrey W.; Quinn, Samuel N.; Ragozzine, Darin; Shporer, Avi; Borucki, William J.; Ciardi, David R.; Gautier, Thomas N., III; Haas, Michael R.; Jenkins, Jon M.; Koch, David G.; Lissauer, Jack J.; Rapin, William; Basri, Gibor S.; Boss, Alan P.; Buchhave, Lars A.; Carter, Joshua A.; Charbonneau, David; Christensen-Dalsgaard, Joergen; Clarke, Bruce D.; Cochran, William D.; Demory, Brice-Olivier; Desert, Jean-Michel; Devore, Edna; Doyle, Laurance R.; Esquerdo, Gilbert A.; Everett, Mark; Fressin, Francois; Geary, John C.; Girouard, Forrest R.; Gould, Alan; Hall, Jennifer R.; Holman, Matthew J.; Howard, Andrew W.; Howell, Steve B.; Ibrahim, Khadeejah A.; Kinemuchi, Karen; Kjeldsen, Hans; Klaus, Todd C.; Li, Jie; Lucas, Philip W.; Meibom, Soren; Morris, Robert L.; Prsa, Andrej; Quintana, Elisa; Sanderfer, Dwight T.; Sasselov, Dimitar; Seader, Shawn E.; Smith, Jeffrey C.; Steffen, Jason H.; Still, Martin; Stumpe, Martin C.; Tarter, Jill C.; Tenenbaum, Peter; Torres, Guillermo; Twicken, Joseph D.; Uddin, Kamal; Van Cleve, Jeffrey; Walkowicz, Lucianne; Welsh, William F.; Cochran, William D.Show more New transiting planet candidates are identified in 16 months (2009 May-2010 September) of data from the Kepler spacecraft. Nearly 5000 periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1108 viable new planet candidates, bringing the total count up to over 2300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multiquarter photo-center offsets derived from difference image analysis that identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the candidates. Ephemerides (transit epoch, T-0, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (R-P / R-star), reduced semimajor axis (d / R-star), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (201% for candidates smaller than 2R(circle plus). compared to 53% for candidates larger than 2R.) and those at longer orbital periods (124% for candidates outside of 50 day orbits versus 86% for candidates inside of 50 day orbits). The gains are larger than expected from increasing the observing window from 13 months (Quarters 1-5) to 16 months (Quarters 1-6) even in regions of parameter space where one would have expected the previous catalogs to be complete. Analyses of planet frequencies based on previous catalogs will be affected by such incompleteness. The fraction of all planet candidate host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the habitable zone are forthcoming if, indeed, such planets are abundant.Show more Item Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: are there Cosmic Microwave Background Anomalies?(2011-02) Bennett, C. L.; Hill, R. S.; Hinshaw, G.; Larson, D.; Smith, K. M.; Dunkley, J.; Gold, B.; Halpern, M.; Jarosik, N.; Kogut, A.; Komatsu, Eiichiro; Limon, M.; Meyer, S. S.; Nolta, M. R.; Odegard, N.; Page, L.; Spergel, D. N.; Tucker, G. S.; Weiland, J. L.; Wollack, E.; Wright, E. L.; Komatsu, EiichiroShow more A simple six-parameter Lambda CDM model provides a successful fit to WMAP data. This holds both when the WMAP data are analyzed alone or in combination with other cosmological data. Even so, it is appropriate to examine the data carefully to search for hints of deviations from the now standard model of cosmology, which includes inflation, dark energy, dark matter, baryons, and neutrinos. The cosmological community has subjected the WMAP data to extensive and varied analyses. While there is widespread agreement as to the overall success of the six-parameter Lambda CDM model, various "anomalies" have been reported relative to that model. In this paper we examine potential anomalies and present analyses and assessments of their significance. In most cases we find that claimed anomalies depend on posterior selection of some aspect or subset of the data. Compared with sky simulations based on the best-fit model, one can select for low probability features of the WMAP data. Low probability features are expected, but it is not usually straightforward to determine whether any particular low probability feature is the result of the a posteriori selection or non-standard cosmology. Hypothesis testing could, of course, always reveal an alternative model that is statistically favored, but there is currently no model that is more compelling. We find that two cold spots in the map are statistically consistent with random cosmic microwave background (CMB) fluctuations. We also find that the amplitude of the quadrupole is well within the expected 95% confidence range and therefore is not anomalously low. We find no significant anomaly with a lack of large angular scale CMB power for the best-fit Lambda CDM model. We examine in detail the properties of the power spectrum data with respect to the Lambda CDM model and find no significant anomalies. The quadrupole and octupole components of the CMB sky are remarkably aligned, but we find that this is not due to any single map feature; it results from the statistical combination of the full-sky anisotropy fluctuations. It may be due, in part, to chance alignments between the primary and secondary anisotropy, but this only shifts the coincidence from within the last scattering surface to between it and the local matter density distribution. While this alignment appears to be remarkable, there was no model that predicted it, nor has there been a model that provides a compelling retrodiction. We examine claims of a hemispherical or dipole power asymmetry across the sky and find that the evidence for these claims is not statistically significant. We confirm the claim of a strong quadrupolar power asymmetry effect, but there is considerable evidence that the effect is not cosmological. The likely explanation is an insufficient handling of beam asymmetries. We conclude that there is no compelling evidence for deviations from the Lambda CDM model, which is generally an acceptable statistical fit to WMAP and other cosmological data.Show more Item Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological interpretation(2011-02) Komatsu, Eiichiro; Smith, K. M.; Dunkley, J.; Bennett, C. L.; Gold, B.; Hinshaw, G.; Jarosik, N.; Larson, D.; Nolta, M. R.; Page, L.; Spergel, D. N.; Halpern, M.; Hill, R. S.; Kogut, A.; Limon, M.; Meyer, S. S.; Odegard, N.; Tucker, G. S.; Weiland, J. L.; Wollack, E.; Wright, E. L.; Komatsu, EiichiroShow more The combination of seven-year data from WMAP and improved astrophysical data rigorously tests the standard cosmological model and places new constraints on its basic parameters and extensions. By combining the WMAP data with the latest distance measurements from the baryon acoustic oscillations (BAO) in the distribution of galaxies and the Hubble constant (H-0) measurement, we determine the parameters of the simplest six-parameter Lambda CDM model. The power-law index of the primordial power spectrum is n(s) = 0.968 +/- 0.012 (68% CL) for this data combination, a measurement that excludes the Harrison-Zel'dovich-Peebles spectrum by 99.5% CL. The other parameters, including those beyond the minimal set, are also consistent with, and improved from, the five-year results. We find no convincing deviations from the minimal model. The seven-year temperature power spectrum gives a better determination of the third acoustic peak, which results in a better determination of the redshift of the matter-radiation equality epoch. Notable examples of improved parameters are the total mass of neutrinos, Sigma m(nu) < 0.58 eV (95% CL), and the effective number of neutrino species, N-eff = 4.34(-0.88)(+0.86) (68% CL), which benefit from better determinations of the third peak and H-0. The limit on a constant dark energy equation of state parameter from WMAP+BAO+H-0, without high-redshift Type Ia supernovae, is w = -1.10 +/- 0.14 (68% CL). We detect the effect of primordial helium on the temperature power spectrum and provide a new test of big bang nucleosynthesis by measuring Y-p = 0.326 +/- 0.075 (68% CL). We detect, and show on the map for the first time, the tangential and radial polarization patterns around hot and cold spots of temperature fluctuations, an important test of physical processes at z = 1090 and the dominance of adiabatic scalar fluctuations. The seven-year polarization data have significantly improved: we now detect the temperature-E-mode polarization cross power spectrum at 21 sigma, compared with 13 sigma from the five-year data. With the seven-year temperature-B-mode cross power spectrum, the limit on a rotation of the polarization plane due to potential parity-violating effects has improved by 38% to Delta a = -1 degrees.1 +/- 1 degrees.4(statistical) +/- 1 degrees.5(systematic) (68% CL). We report significant detections of the Sunyaev-Zel'dovich (SZ) effect at the locations of known clusters of galaxies. The measured SZ signal agrees well with the expected signal from the X-ray data on a cluster-by-cluster basis. However, it is a factor of 0.5-0.7 times the predictions from "universal profile" of Arnaud et al., analytical models, and hydrodynamical simulations. We find, for the first time in the SZ effect, a significant difference between the cooling-flow and non-cooling-flow clusters (or relaxed and non-relaxed clusters), which can explain some of the discrepancy. This lower amplitude is consistent with the lower-than-theoretically expected SZ power spectrum recently measured by the South Pole Telescope Collaboration.Show more