Cosmic temperature fluctuations from two years of COBE differential microwave radiometers observations

Bennett, C. L.; Loewenstein, K.; Cheng, E. S.; Lineweaver, Charles H.; Wilkinson, David T.; Keegstra, P.; Górski, K. M.; Mather, John C.; Meyer, S. S.; Banday, A. J.; Weiß, R.; Hinshaw, G.; Smoot, George F.; Kogut, A.; Wright, E. L.; Lubin, P. M.; Jackson, P. D.; Kaita, Ed

doi:10.1086/174918

Cited by 230 publications

(125 citation statements)

References 47 publications

(83 reference statements)

Supporting

Mentioning

108

Contrasting

Unclassified

Order By: Relevance

“…For example, for an in ation energy 10 17 GeV and an e{folding of 100, the H{Z spectrum is modi ed by our perturbation on physical scales in the interval (1 10 4 ) h 1 Mp c 1 (we adopt the value h = 0 : 5 for the present v alue of the Hubble constant H 0 in units of 100km s 1 Mp c 1 ). However, from the analysis of present in ationary models [12] one obtains that standard and chaotic in ation is consistent with the COBE results [13] [14] only for energies 10 14 GeV and in order to obtain a higher energy one should construct models with suitable e{folding and/or a horizon growth during in ation steeper than that presently used [12].…”

supporting

confidence: 70%

“…(14) aa a 2 n + 1 2 S (n) bb b 2 n + 1 2 S (n) ff f 2 n + S ( n) ab a n b n + S (n) af a n f n + S (n) bf b n f n ; (16) which is substituted into eq. (14). On equating coe cients of the same order in a n ; b n ; f n , a series of relations are then obtained and solved.…”

mentioning

confidence: 99%

“…However, it is now known that this model has some serious problems, mostly due to the high ratio of small to large{scale power. In particular, the COBE normalization [13] [14] implies excessive v elocity dispersion on Mp c scales [15] and is unable to reproduce the slope of the galaxy angular correlation function obtained from the APM survey [17]. The spectrum of the primordial uctuations in the CDM model is the H{Z spectrum and, as mentioned, our non{adiabatic uctuations modify this spectrum at small and very large scales.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Semiclassical Gravity and Large-Scale Structure

Bertoni

Carretti

Finelli⋆

et al. 1995

Computational Mechanics ’95

View full text Add to dashboard Cite

The possible cosmological e ects of primordial non{adiabatic uctuations in the matter{gravity quantum system are explored. In particular, both the metric and a scalar matter eld are expanded around their homogeneous values and the corrections induced on the scalar eld uctuation spectrum by the non{adiabatic terms are perturbatively estimated. Finally, results of a preliminary numerical simulation to investigate the e ects on large{scale structure formation are presented.The invariance of the Einstein action under arbitrary space{time transformations has as a consequence that time does not appear in the corresponding Hamiltonian formulation and such a feature is maintained in the canonical quantization of gravity within the superspace approach [ 1 ] [2].It has been observed, however, that the introduction of matter allows one to also introduce the concept of time: time parametrizes how matter follows gravity. In particular, it has been noted that the semiclassical wave function for gravity provides a parametrization for the evolution of matter in which the latter follows the former adiabatically [3] [ 4 ].In order to illustrate the above the matter{gravity w a v e function is factorized into two parts: one involving only gravitational degrees of freedom and the other involving both the gravitational and the matter degrees of freedom. Correspondingly, the Wheeler{De Witt (WD) equation in which time is absent is split into two pieces: one describing gravitation in an e ective potential given by the mean energy{momentum tensor of matter and the other describing the matter whose evolution is parametrized by time which is derived from the semiclassical approximation to the gravitational wave function [4]. The above is contingent on the hypothesis that the Planck mass is much larger than the mass of any matter eld or any i n v erse length scale used to describe matter.

show abstract

supporting

confidence: 70%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Semiclassical Gravity and Large-Scale Structure

Bertoni

Carretti

Finelli⋆

et al. 1995

Computational Mechanics ’95

View full text Add to dashboard Cite

show abstract

“…For the total gas mass inferred from the modeling of the dust FIR continuum (1.6 × 10 9 M ), this corresponds to a [Cii] cooling rate λ C + = 1.4 ×10 −25 erg s −1 H −1 for our estimate of G 0 ≈ 9. This is a factor 5 higher than for the diffuse ISM in the Milky Way (2.6 × 10 −26 erg s −1 H −1 , Bennett et al 1994).…”

Section: Dust and Gas Massesmentioning

confidence: 70%

Exceptional AGN-driven turbulence inhibits star formation in the 3C 326N radio galaxy

Guillard

Boulanger

Lehnert

et al. 2015

A&A

View full text Add to dashboard Cite

We detect bright [Cii]λ158 μm line emission from the radio galaxy 3C 326N at z = 0.09, which shows no sign of ongoing or recent star formation (SFR < 0.07 M yr −1 ) despite having strong H 2 line emission and a substantial amount of molecular gas (2 × 10 9 M , inferred from the modeling of the far-infrared (FIR) dust emission and the CO(1−0) line emission). The [Cii] line is twice as strong as the 0−0S(1) 17 μm H 2 line, and both lines are much in excess of what is expected from UV heating. We combine infrared Spitzer and Herschel photometry and line spectroscopy with gas and dust modeling to infer the physical conditions in the [Cii]-emitting gas. The [Cii] line, like rotational H 2 emission, traces a significant fraction (30 to 50%) of the total molecular gas mass. This gas is warm (70 < T < 100 K) and at moderate densities 700 < n H < 3000 cm [Cii] is similar to the profiles of the near-infrared H 2 lines and the Na D optical absorption lines, and is likely to be shaped by a combination of rotation, outflowing gas, and turbulence. If the line wing is interpreted as an outflow, the mass loss rate would be higher than 20 M yr −1 , and the depletion timescale close to the orbital timescale (≈3 × 10 7 yr). If true, we are observing this object at a very specific and brief time in its evolution, assuming that the disk is not replenished. Although there is evidence of an outflow in this source, we caution that the outflow rates may be overestimated because the stochastic injection of turbulent energy on galactic scales can create short-lived, large velocity increments that contribute to the skewness of the line profile and mimic outflowing gas. The gas physical conditions raise the issue of the heating mechanism of the warm gas, and we show that the dissipation of turbulent energy is the main heating process. Cosmic rays can also contribute to the heating, but cannot be the dominant heating source because it requires an average gas density that is higher than the observational constraints. After subtracting the contribution of the disk rotation, we estimate the turbulent velocity dispersion of the molecular gas to be 120 < σ turb < 330 km s −1 , which corresponds to a turbulent heating rate that is higher than the gas cooling rate computed from the line emission. The dissipation timescale of the turbulent energy (2 × 10 7 −10 8 yrs) is comparable to or larger than the jet lifetime or the dynamical timescale of the outflow, which means that turbulence can be sustained during the quiescent phases when the radio jet is shut off. The strong turbulent support maintains a very high gas scale height (0.3 to 4 kpc) in the disk. The cascade of turbulent energy can inhibit the formation of gravitationally bound structures on all scales, which offers a natural explanation for the lack of ongoing star formation in 3C 326N, despite its having sufficient molecular gas to form stars at a rate of a few solar mass per year. To conclude, the bright [Cii] line indicates that strong AGN jet-driven turbulence may play a key ...

show abstract

“…The COBE DMR four years' observational data (Bennett et al 1994) are used as recommended by the COBE team. These are made available (web address in acknowledgments) as dipole subtracted, foreground corrected 'DMR Analysed Science Data Sets' (hereafter, ASDS).…”

Section: Observationsmentioning

confidence: 99%

A counterexample to claimed COBE constraints on compact toroidal universe models

Roukema

2000

Class. Quantum Grav.

View full text Add to dashboard Cite

It has been suggested that if the Universe satisfies a flat, multiply connected, perturbed FriedmannLemaître model, then cosmic microwave background data from the COBE satellite implies that the minimum size of the injectivity diameter (shortest closed spatial geodesic) must be larger than about two fifths of the horizon diameter. To show that this claim is misleading, a simple T 2 ×R universe model of injectivity diameter a quarter of this size, i.e. a tenth of the horizon diameter, is shown to be consistent with COBE four year observational maps of the cosmic microwave background. This is done using the identified circles principle.

show abstract

Cosmic temperature fluctuations from two years of COBE differential microwave radiometers observations

Cited by 230 publications

References 47 publications

Semiclassical Gravity and Large-Scale Structure

Semiclassical Gravity and Large-Scale Structure

Exceptional AGN-driven turbulence inhibits star formation in the 3C 326N radio galaxy

A counterexample to claimed COBE constraints on compact toroidal universe models

Contact Info

Product

Resources

About