Calibrator Design for the<i>COBE</i>Far‐Infrared Absolute Spectrophotometer (FIRAS)

Mather, John C.; Fixsen, D. J.; Shafer, R. A.; Mosier, Carol L.; Wilkinson, D. T.

doi:10.1086/306805

Cited by 487 publications

(591 citation statements)

References 22 publications

(25 reference statements)

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“…Following a detailed analysis of the FIRAS data (Fixsen et al 1996) we removed a model consisting of a spatially uniform blackbody spectrum with a temperature of T ¼ 2:7275 K (the final recalibration has not been applied to Pass 4 data) and a dipole component with T ¼ 3:368 mK from the sky maps. Any errors in the data caused by thermometry errors (Mather et al 1999) are on the 30 lK level and are negligible for studying the ZD cloud.…”

Section: Cmb Cib Ism and Zd Emission Spectramentioning

confidence: 99%

The Zodiacal Emission Spectrum as Determined byCOBEand Its Implications

Fixsen

Dwek

2002

ApJ

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We combine observations from the DIRBE and FIRAS instruments on the COBE satellite to derive an annually averaged spectrum of the zodiacal cloud in the 10-1000 lm wavelength region. The spectrum exhibits a break at $150 lm that indicates a sharp break in the dust size distribution at a radius of about 30 lm. The spectrum can be fitted with a single blackbody with a À2 emissivity law beyond 150 lm and a temperature of 240 K. We also used a more realistic characterization of the cloud to fit the spectrum, including a distribution of dust temperatures representing different dust compositions and distances from the Sun, as well as a realistic representation of the spatial distribution of the dust. We show that amorphous carbon and silicate dust with respective temperatures of 280 and 274 K at 1 AU, and size distributions with a break at grain radii of 14 and 32 lm, can provide a good fit to the average zodiacal dust spectrum. The total mass of the zodiacal cloud is 2-11 Eg (Eg ¼ 10 18 g), depending on the grain composition.

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Section: Cmb Cib Ism and Zd Emission Spectramentioning

confidence: 99%

The Zodiacal Emission Spectrum as Determined byCOBEand Its Implications

Fixsen

Dwek

2002

ApJ

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100

120

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“…The reason for this is that the horizon scale of the scalar field model at the time of recombination is greater compared with that of the ΛCDM model because the effective gravitational constant G eff is smaller in the past. The opposite is true in the case of the scalar field model of Nagata et al (2004), for which the value of G eff is larger in the past.…”

Section: Cosmological Model With Morikawa's Scalarmentioning

confidence: 95%

“…Here, we employ ξ = −1 and −3, the absolute values of which are an order of magnitude smaller than that inferred from the previous analysis of the N -z relation of galaxies(ξ = −40). The values of the other parameters are as follows: Ω m,0 = 0.237, Ω b,0 h 2 100 = 0.024, Ω φ,0 = 0.15(hence Ω Λ,0 = 0.613), m φ = 3.7 × 10 −31 h 100 eV, h 100 = 0.72 (Freedman et al 2001), n s = 1 is the spectral index (Harrison-Zel'dovich spectrum) for the initial condition for the matter density perturbation, T CMB,0 = 2.726 K (Mather et al 1999) for the present CMB temperature, and the optical depth of our universe is τ = 0.089 for the CMB, (Spergel et al 2007), which, together with ξ = −40, characterize the best-fit model proposed in the present study. Furthermore, we adopt Y He = 0.24 for the cosmic abundance(by mass) of He and 3.04 for the number of neutrino species (Nagata et al 2004).…”

Section: Cosmological Model With Morikawa's Scalarmentioning

confidence: 99%

“…The values of the other parameters are as follows: Ω m,0 = 0.237, Ω b,0 h 2 100 = 0.024, Ω φ,0 = 0.15(hence Ω Λ,0 = 0.613), m φ = 3.7 × 10 −31 h 100 eV, h 100 = 0.72 (Freedman et al 2001), n s = 1 is the spectral index (Harrison-Zel'dovich spectrum) for the initial condition for the matter density perturbation, T CMB,0 = 2.726 K (Mather et al 1999) for the present CMB temperature, and the optical depth of our universe is τ = 0.089 for the CMB, (Spergel et al 2007), which, together with ξ = −40, characterize the best-fit model proposed in the present study. Furthermore, we adopt Y He = 0.24 for the cosmic abundance(by mass) of He and 3.04 for the number of neutrino species (Nagata et al 2004). Also shown in Fig.9 is the theoretical spectrum computed for the ΛCDM model adopting Ω b,0 h 2 100 = 0.02229, Ω m,0 h 2 100 = 0.1277, h 100 = 0.732, n s = 0.958, and τ = 0.089 derived by the WMAP team (Spergel et al 2007) together with the WMAP 3-yr data.…”

Section: Cosmological Model With Morikawa's Scalarmentioning

confidence: 99%

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Spatial periodicity of galaxy number counts, CMB anisotropy, and SNIa Hubble diagram based on the universe accompanied by a non-minimally coupled scalar field

Hirano

Kawabata

Komiya

2008

Astrophys Space Sci

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We have succeeded in establishing a cosmological model with a non-minimally coupled scalar field φ that can account not only for the spatial periodicity or the picket-fence structure exhibited by the galaxy N -z relation of the 2dF survey but also for the spatial power spectrum of the cosmic microwave background radiation (CMB) temperature anisotropy observed by the WMAP satellite. The Hubble diagram of our model also compares well with the observation of Type Ia supernovae. The scalar field of our model universe starts from an extremely small value at around the nucleosynthesis epoch, remains in that state for sufficiently long periods, allowing sufficient time for the CMB temperature anisotropy to form, and then starts to grow in magnitude at the redshift z of ∼ 1, followed by a damping oscillation which is required to reproduce the observed picket-fence structure of the N -z relation. To realize such behavior of the scalar field, we have found it necessary to introduce a new form of potential V (φ) ∝ φ 2 exp(−qφ 2 ), with q being a constant. Through this parameter q, we can control the epoch at which the scalar field starts growing.

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“…3.2.3), we base all string simulations on the single testing string simulation (Fig. 6(b)), smoothing with a 7.3 arcmin Gaussian beam and rescaling by the appropriate T 0 Gµ (assuming the mean CMB temperature of T 0 = 2.725 K; Mather et al 1999). We do not touch the training string simulation (Fig.…”

Section: Simulationsmentioning

confidence: 99%

Wavelet-Bayesian inference of cosmic strings embedded in the cosmic microwave background

McEwen

Feeney

Peiris

et al. 2017

Monthly Notices of the Royal Astronomical Society

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Cosmic strings are a well-motivated extension to the standard cosmological model and could induce a subdominant component in the anisotropies of the cosmic microwave background (CMB), in addition to the standard inflationary component. The detection of strings, while observationally challenging, would provide a direct probe of physics at very high energy scales. We develop a framework for cosmic string inference from observations of the CMB made over the celestial sphere, performing a Bayesian analysis in wavelet space where the string-induced CMB component has distinct statistical properties to the standard inflationary component. Our wavelet-Bayesian framework provides a principled approach to compute the posterior distribution of the string tension Gµ and the Bayesian evidence ratio comparing the string model to the standard inflationary model. Furthermore, we present a technique to recover an estimate of any string-induced CMB map embedded in observational data. Using Planck-like simulations we demonstrate the application of our framework and evaluate its performance. The method is sensitive to Gµ ∼ 5 × 10 −7 for Nambu-Goto string simulations that include an integrated Sachs-Wolfe (ISW) contribution only and do not include any recombination effects, before any parameters of the analysis are optimised. The sensitivity of the method compares favourably with other techniques applied to the same simulations.

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Calibrator Design for theCOBEFar‐Infrared Absolute Spectrophotometer (FIRAS)

Cited by 487 publications

References 22 publications

The Zodiacal Emission Spectrum as Determined byCOBEand Its Implications

The Zodiacal Emission Spectrum as Determined byCOBEand Its Implications

Spatial periodicity of galaxy number counts, CMB anisotropy, and SNIa Hubble diagram based on the universe accompanied by a non-minimally coupled scalar field

Wavelet-Bayesian inference of cosmic strings embedded in the cosmic microwave background

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