scholarly journals Measurement and Implications of the Cosmic Microwave Background Spectrum

1996 ◽  
Vol 168 ◽  
pp. 17-29
Author(s):  
John C. Mather
Keyword(s):  
Background Radiation ◽  
Far Infrared ◽  
Big Bang ◽  
Scale Invariant ◽  
Background Spectrum ◽  
Nasa Goddard Space ◽  
Wide Range ◽  
Infrared Background ◽  
Microwave Radiometers ◽  
The Big Bang

The Cosmic Background Explorer (COBE) was developed by NASA Goddard Space Flight Center to measure the diffuse infrared and microwave radiation from the early universe. It also measured emission from nearby sources such as the stars, dust, molecules, atoms, ions, and electrons in the Milky Way, and dust and comets in the Solar System. It was launched 18 November 1989 on a Delta rocket, carrying one microwave instrument and two cryogenically cooled infrared instruments. The Far Infrared Absolute Spectrophotometer (FIRAS) mapped the sky at wavelengths from 0.01 to 1 cm, and compared the CMBR to a precise blackbody. The spectrum of the CMBR differs from a blackbody by less than 0.03%. The Differential Microwave Radiometers (DMR) measured the fluctuations in the CMBR originating in the Big Bang, with a total amplitude of 11 parts per million on a 10° scale. These fluctuations are consistent with scale-invariant primordial fluctuations. The Diffuse Infrared Background Experiment (DIRBE) spanned the wavelength range from 1.2 to 240 μm and mapped the sky at a wide range of solar elongation angles to distinguish foreground sources from a possible extragalactic Cosmic Infrared Background Radiation (CIBR). In this paper we summarize the COBE mission and describe the results from the FIRAS instrument. The results from the DMR and DIRBE were described by Smoot and Hauser at this Symposium.

scholarly journals The Far Infrared and Submillimeter Diffuse Extragalactic Background

2001 ◽  
Vol 204 ◽  
pp. 101-118 ◽  
Author(s):  
M. G. Hauser
Keyword(s):  
Galaxy Evolution ◽  
Near Infrared ◽  
Current Knowledge ◽  
Far Infrared ◽  
Big Bang ◽  
Millimeter Wavelengths ◽  
Submillimeter Wavelengths ◽  
The Status ◽  
Infrared Background ◽  
The Big Bang

The cosmic infrared background (CIB) radiation was a long-sought fossil of energetic processes associated with structure formation and chemical evolution since the Big Bang. The COBE Diffuse Infrared Background Experiment (DIRBE) and Far Infrared Absolute Spectrophotometer (FIRAS) were specifically designed to search for this background from 1.25 μm to millimeter wavelengths. These two instruments provided high quality, absolutely calibrated all-sky maps which have enabled the first detections of the CIB, initially at far infrared and submillimeter wavelengths, and more recently in the near infrared as well. The aim of this paper is to review the status of determinations of the CIB based upon COBE measurements. The results show that the energy in the CIB from far infrared to millimeter wavelengths is comparable to that in the integrated light of galaxies from UV to near infrared wavelengths: the universe had a luminous but dusty past. On the assumption that nucleosynthesis in stars is the energy source for most of this light, the results also imply that 1–8% of cosmic baryons has been converted to helium and heavier elements in stars. The integrated background light from UV to millimeter wavelengths, 60–120 nW m−2 sr−1, is about 10% of that in the cosmic microwave background. Current knowledge of the CIB provides significant new constraints on models of the history of star formation and galaxy evolution.

scholarly journals Revisiting cosmic microwave background radiation using blackbody radiation inversion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Koustav Konar ◽  
Kingshuk Bose ◽  
R. K. Paul
Keyword(s):  
Temperature Distribution ◽  
Cosmic Microwave Background ◽  
Background Radiation ◽  
Big Bang ◽  
Blackbody Radiation ◽  
Microwave Background ◽  
Background Spectrum ◽  
Microwave Background Radiation ◽  
Mathematical Process

AbstractBlackbody radiation inversion is a mathematical process for the determination of probability distribution of temperature from measured radiated power spectrum. In this paper a simple and stable blackbody radiation inversion is achieved by using an analytical function with three determinable parameters for temperature distribution. This inversion technique is used to invert the blackbody radiation field of the cosmic microwave background, the remnant radiation of the hot big bang, to infer the temperature distribution of the generating medium. The salient features of this distribution are investigated and analysis of this distribution predicts the presence of distortion in the cosmic microwave background spectrum.

Primal Emergence

2017 ◽  
Author(s):  
John L. Culliney ◽  
David Jones
Keyword(s):  
Background Radiation ◽  
Quantum Turbulence ◽  
Big Bang ◽  
Point Of View ◽  
Microwave Background ◽  
Creation Story ◽  
Catalytic Potential ◽  
Microwave Background Radiation ◽  
Nuclear Synthesis ◽  
The Big Bang

Since the Big Bang, the universe’s inflation and its aftermath might be called the “creation story” according to science, in which tremendously variegated order and deterministic pattern propagated from a cosmic seed of perfect uniformity and smoothness. The formative properties of matter and energy were forged through initial quantum turbulence and an emergent principle of attraction that seems to pervade all of nature. As it emerged out of simplicity, the universe adopted a modus operandi that we call the cooperative constant, initially manifested in physical forces, especially gravity, and progressively complemented by chemistry. From an evolutionary point of view, an emergent catalytic potential, an attraction to cooperate, or participate in heterogeneity—which becomes a sine qua non for the existence of life—is widely characteristic of matter in our universe. This tendency is now found at the heart of the most progressive systems of which we are aware. Chapter One weaves its cosmological story through leading theories and revelations in astrophysics including primordial quantum turbulence, the multiverse, recombination, and the origin of the cosmic microwave background radiation (CMB), also the enigmas of dark matter and dark energy, and nuclear synthesis of the elements of life within stars.

scholarly journals Early Results From the Cosmic Background Explorer (COBE)

1990 ◽  
Vol 123 ◽  
pp. 9-18
Author(s):  
J. C. Mather ◽  
M. G. Hauser ◽  
C. L. Bennett ◽  
N. W. Boggess ◽  
E. S. Cheng ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Zero Point ◽  
Far Infrared ◽  
Strong Limit ◽  
Cosmic Background ◽  
Early Results ◽  
Local Sources ◽  
Infrared Background ◽  
Reduction Methods ◽  
Microwave Radiometers

AbstractThe Cosmic Background Explorer, launched November 18, 1989, has nearly completed its first full mapping of the sky with all three of its instruments: a Far Infrared Absolute Spectrophotometer (FIRAS) covering 0.1 to 10 mm, a set of Differential Microwave Radiometers (DMR) operating at 3.3, 5.7, and 9.6 mm, and a Diffuse Infrared Background Experiment (DIRBE) spanning 1 to 300 µm in ten bands. A preliminary map of the sky derived from DIRBE data is presented. Initial cosmological implications include: a limit on the Comptonization y parameter of 10−3, on the chemical potential μ parameter of 10−2, a strong limit on the existence of a hot smooth intergalactic medium, and a confirmation that the dipole anisotropy has the spectrum expected from a Doppler shift of a blackbody. There are no significant anisotropies in the microwave sky detected, other than from our own galaxy and a cosθ dipole anisotropy whose amplitude and direction agree with previous data. At shorter wavelengths, the sky spectrum and anisotropies are dominated by emission from ‘local’ sources of emission within our Galaxy and Solar System. Preliminary comparison of IRAS and DIRBE sky brightnesses toward the ecliptic poles shows the IRAS values to be significantly higher than found by DIRBE at 100 μm. We suggest the presence of gain and zero-point errors in the IRAS total brightness data. The spacecraft, instrument designs, and data reduction methods are described.

scholarly journals Big bounce with finite-time singularity: The F(R) gravity description

2017 ◽  
Vol 26 (08) ◽  
pp. 1750085 ◽  
Author(s):  
S. D. Odintsov ◽  
V. K. Oikonomou
Keyword(s):  
Big Bang ◽  
Einstein Frame ◽  
Jordan Frame ◽  
Cosmological Perturbations ◽  
Scale Invariant ◽  
Type Iv ◽  
Big Rip ◽  
Cosmological Scenario ◽  
The Big Bang ◽  
Big Bounce

An alternative to the Big Bang cosmologies is obtained by the Big Bounce cosmologies. In this paper, we study a bounce cosmology with a Type IV singularity occurring at the bouncing point in the context of [Formula: see text] modified gravity. We investigate the evolution of the Hubble radius and we examine the issue of primordial cosmological perturbations in detail. As we demonstrate, for the singular bounce, the primordial perturbations originating from the cosmological era near the bounce do not produce a scale-invariant spectrum and also the short wavelength modes after these exit the horizon, do not freeze, but grow linearly with time. After presenting the cosmological perturbations study, we discuss the viability of the singular bounce model, and our results indicate that the singular bounce must be combined with another cosmological scenario, or should be modified appropriately, in order that it leads to a viable cosmology. The study of the slow-roll parameters leads to the same result indicating that the singular bounce theory is unstable at the singularity point for certain values of the parameters. We also conformally transform the Jordan frame singular bounce, and as we demonstrate, the Einstein frame metric leads to a Big Rip singularity. Therefore, the Type IV singularity in the Jordan frame becomes a Big Rip singularity in the Einstein frame. Finally, we briefly study a generalized singular cosmological model, which contains two Type IV singularities, with quite appealing features.

When language bites

2017 ◽  
Vol 24 (2) ◽  
pp. 186-211
Author(s):  
Sabina Tabacaru
Keyword(s):  
Descriptive Analysis ◽  
Big Bang ◽  
Television Series ◽  
The Core ◽  
Wide Range ◽  
Big Bang Theory ◽  
Holistic Analysis ◽  
Rhetorical Questions ◽  
The Big Bang ◽  
Large Corpus

Abstract This article focuses on sarcasm, for which the definitions have often been loose and confusing, integrating it into the concept of irony. My approach is based on a large corpus of examples taken from two contemporary television-series, which help identify the wide range of linguistic processes at the core of sarcastic utterances. I present a quantitative and descriptive analysis of the main processes found in two American television-series: House M.D. and The Big Bang Theory. The results show the intricate meanings created in sarcasm through various linguistic mechanisms, such as repetition, explicitation, metonymy, metaphor, shift of focus, reasoning, and rhetorical questions. This more holistic analysis, including a broad corpus of instances and a more detailed analysis of the examples, aims to fill the unexplored gaps in more classical analyses, emphasizing the complexities and implications that can be drawn in interaction.

scholarly journals Observation and Interpretation of the Cosmic Microwave Background Spectrum

1992 ◽  
Vol 9 ◽  
pp. 275-279 ◽  
Author(s):  
J. C. Mather
Keyword(s):  
Cosmic Microwave Background ◽  
Background Radiation ◽  
Far Infrared ◽  
Cosmic Background Radiation ◽  
Microwave Measurements ◽  
Microwave Background ◽  
Background Spectrum ◽  
Cosmic Background

AbstractRecent precise observations of the microwave and submillimeter cosmic background radiation are summarized, including rocket experiments, the FIRAS (Far InfraRed Absolute Spectrophotometer) on the COBE, CN results, and microwave measurements. Theoretical implications are summarized.

scholarly journals Large Scale Anisotropy of the Cosmic Microwave Background

1974 ◽  
Vol 63 ◽  
pp. 157-162 ◽  
Author(s):  
R. B. Partridge
Keyword(s):  
Angular Distribution ◽  
Large Scale ◽  
Background Radiation ◽  
Big Bang ◽  
Microwave Background ◽  
Initial State ◽  
Microwave Background Radiation ◽  
Cosmological Data ◽  
The Big Bang ◽  
The Universe

It is now generally accepted that the microwave background radiation, discovered in 1965 (Penzias and Wilson, 1965; Dicke et al., 1965), is cosmological in origin. Measurements of the spectrum of the radiation, discussed earlier in this volume by Blair, are consistent with the idea that the radiation is in fact a relic of a hot, dense, initial state of the Universe – the Big Bang. If the radiation is cosmological, measurements of both its spectrum and its angular distribution are capable of providing important – and remarkably precise – cosmological data.

scholarly journals Constraints on Far-Infrared Source Counts in the Lockman Hole using a Power Spectrum Analysis

2001 ◽  
Vol 204 ◽  
pp. 301-301
Author(s):  
H. Matsuhara ◽  
K. Kawara ◽  
Y. Sofue ◽  
Y. Taniguchi ◽  
Y. Sato ◽  
...  
Keyword(s):  
Background Radiation ◽  
Power Spectra ◽  
Far Infrared ◽  
Infrared Space Observatory ◽  
Infrared Source ◽  
Star Forming ◽  
The Galaxy ◽  
Galaxy Count ◽  
Infrared Background ◽  
Lockman Hole

We present the characteristics of far-infrared (FIR) brightness fluctuations at 90 μm and 170 μm in the Lockman Hole, which were surveyed with the ISOPHOT instrument aboard the Infrared Space Observatory (ISO), and give constraints on the galaxy number counts down to 30 mJy at 90 μm and 50 mJy at 170 μm. The fluctuation power spectra of the FIR images are not dominated by IR cirrus, and are instead most likely due to star-forming galaxies. This analysis indicates the existence of strong evolution in the counts. Especially at 90 μm, the source density is much larger than that expected from the currently available galaxy count models. The galaxies responsible for the fluctuations also significantly contribute to the cosmic infrared background radiation recently derived from an analysis of the COBE data.

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