Far-infrared Background Radiation Research Articles

Mathematical Overview of Hypersphere World-Universe Model

The Hypersphere World-Universe Model (WUM) provides a mathematical framework that allows calculating the primary cosmological parameters of the World which are in good agreement with the most recent measurements and observations. WUM explains the experimental data accumulated in the field of Cosmology and Astroparticle Physics over the last decades: the age of the World and critical energy density; the gravitational parameter and Hubble’s parameter; temperatures of the cosmic microwave background radiation and the peak of the far-infrared background radiation; the concentration of intergalactic plasma and time delay of Fast Radio Bursts. Additionally, the model predicts masses of dark matter particles, photons, and neutrinos; proposes new types of particle interactions (Super Weak and Extremely Weak); shows inter-connectivity of primary cosmological parameters of the World. WUM proposes to introduce a new fundamental parameter Q in the CODATA internationally recommended values. This paper is the summary of the mathematical results obtained in [1]-[4].

Overview of Hypersphere World-Universe Model

This paper provides an overview of the Hypersphere World-Universe Model (WUM). WUM unifies and simplifies existing cosmological models and results into a single coherent picture, and proceeds to discuss the origin, evolution, structure, ultimate fate, and primary parameters of the World. WUM explains the experimental data accumulated in the field of Cosmology and Astroparticle Physics over the last decades: the age of the world and critical energy density; the gravitational parameter and Hubble’s parameter; temperatures of the cosmic microwave background radiation and the peak of the far-infrared background radiation; gamma-ray background and cosmic neutrino background; macrostructure of the world and macroobjects structure. Additionally, the model makes predictions pertaining to masses of dark matter particles, photons, and neutrinos, proposes new types of particle interactions (Super Weak and Extremely Weak), and shows inter-connectivity of primary cosmological parameters of the world and the rise of the solar luminosity during the last 4.6 Byr. The model proposes to introduce a new fundamental parameter Q in the CODATA internationally recommended values.

5D World-Universe Model. Neutrinos. The World

In this manuscript we discuss mass-varying neutrinos and propose their energy density to exceed that of baryonic and dark matter. We introduce cosmic Large Grains whose mass is about Planck mass, and their temperature is around 29 K. Large Grains are in fact Bose-Einstein condensates of proposed dineutrinos, and are responsible for the cosmic Far-Infrared Background (FIRB) radiation. The distribution of the energy density of all components of the World (protons, electrons, photons, neutrinos, and dark matter particles) is considered. We present an overview of the World- Universe Model (WUM) and pay particular attention to the self-consistent set of time-varying values of basic parameters of the World: the age and critical energy density; Newtonian parameter of gravitation and Hubble’s parameter; temperatures of the cosmic Microwave Background radiation and the peak of the cosmic FIRB radiation; Fermi coupling parameter and coupling parameters of the proposed Super-Weak and Extremely-Weak interactions. Additionally, WUM forecasts the masses of dark matter particles, axions, and neutrinos; proposes two fundamental parameters of the World: fine-structure constant α and the quantity Q which is the dimensionless value of the fifth coordinate, and three fundamental physical units: basic unit of momentum, energy density, and energy flux density. WUM suggests that all time-dependent parameters of the World are inter- connected and in fact dependent on Q. We recommend adding the quantity Q to the list of the CODATA-recommended values.

Thermal physics, cloud geometry and the stellar initial mass function

The thermal properties of star-forming clouds have an important influence on how they fragment into stars, and it is suggested in this paper that the low-mass stellar initial mass function (IMF), which appears to be almost universal, is determined largely by the thermal physics of these clouds. In particular, it is suggested that the characteristic stellar mass, a little below one solar mass, is determined by the transition from an initial cooling phase of collapse to a later phase of slowly rising temperature that occurs when the gas becomes thermally coupled to the dust. Numerical simulations support the hypothesis that the Jeans mass at this transition point plays an important role in determining the peak mass of the IMF. A filamentary geometry may also play a key role in the fragmentation process because the isothermal case is a critical one for the collapse of a cylinder: the collapse and fragmentation of a cylinder can continue freely as long as the temperature continues to decrease, but not if it begins to increase. The limited available results on the dependence of the thermal properties of clouds on metallicity do not suggest a strong dependence of the IMF on metallicity, but the far-infrared background radiation in starburst regions and in the early Universe may significantly shift the peak mass to higher masses in these situations.

Prospects for Future Far-Infrared/Submillimeter Studies of the High-Redshift Universe

AbstractObservations made using COBE, SCUBA, ISO and MAMBO have provided a reasonable working knowledge of both the intensity of the submm and far-infrared background radiation and the source counts of luminous high-redshift dusty galaxies. However, because there are uncertainties in the background intensity determinations, the samples of detected galaxies are small, and most importantly, their redshift distributions are very incomplete, details of the evolution of dusty galaxies remain unresolved. The next steps forward in the field will be the launches of SIRTF and ASTRO-F, the commissioning of SOFIA and new, more capable ground-based mm/submm-wave cameras - BOLOCAM, SHARC-II and SCUBA-II - the use of ultra-long duration balloon experiments, such as BLAST, the construction of ALMA and the arrival of FIRST, and ultimately the advent of space-borne far-infrared interferometers, such as SPECS. There are also exciting prospects for direct mm/submm-wave CO-line redshift surveys using wide-band spectrographs. Using these new facilities, the number of high-redshift dusty galaxies known will be increased dramatically. Spectroscopy using SIRTF, SOFIA and FIRST will probe the astrophysical processes within these sources in detail, hopefully addressing the open question of the fraction of the counts and background radiation that is generated by the formation of high-mass stars and by active galactic nuclei (AGNs). The spatial and spectral structure of distant dusty galaxies will finally be resolved in detail using ALMA and SPECS.

The temperatures of dust-enshrouded active galactic nuclei

A high density of massive dark objects (MDOs), probably supermassive black holes, in the centres of nearby galaxies has been inferred from recent observations. There are various indications that much of the accretion responsible for producing these objects took place in dust-enshrouded active galactic nuclei (AGNs). If so, then measurements of the intensity of background radiation and the source counts in the far-infrared and submillimetre wavebands constrain the temperature of dust in these AGNs. An additional constraint comes from the hard X-ray background, if this is produced by accretion. One possibility is that the dust shrouds surrounding the accreting AGNs are cold, about 30 K. In this event, the dusty AGNs could be some subset of the population of luminous distant sources discovered at 850 microns using the SCUBA array on the JCMT, as proposed by Almaini et al. (1999). An alternative is that the dust shrouds surrounding the accreting AGNs are much hotter (> 60 K). These values are closer to the dust temperatures of a number of well-studied low-redshift ultraluminous galaxies that are thought to derive their power from accretion. If the local MDO density is close to the maximum permitted, then cold sources cannot produce this density without the submillimetre background being overproduced if they accrete at high radiative efficiency, and thus a hot population is required. If the dust-enshrouded accretion occurred at similar redshifts to that taking place in unobscured optical quasars, then a significant fraction of the far-infrared background radiation measured by COBE at 140 microns, but very little of the submilllimetre background at 850 microns, may have been produced by hot dust-enshrouded AGNs which may have already been seen in recent X-ray surveys.

Ultraluminous infrared galaxies at high redshift: their position on the Madau plot and their fate

A major recent development in extragalactic astronomy has been the discovery of a population of galaxies that is luminous at submillimetre wavelengths. Estimates of their spectral energy distributions suggest that these galaxies are the high-redshift analogues of the ultraluminous infrared galaxies (ULIRGs) observed locally. Here we investigate the implications for the galaxy formation problem if this is indeed the case. We identify plausible (but non-unique) redshift-dependent galaxy luminosity functions that are consistent with both source counts at 2800, 850, 450 and 175 μ m and far-infrared background radiation intensities at 850, 240 and 140 μ m. In all our models, most of the submillimetre-luminous sources are distant galaxies with high bolometric luminosities ≥ 1012 L⊙. As for many local ULIRGs, it is not possible to determine whether these luminous galaxies are powered by starbursts, like the local galaxy Arp 220, or by active galactic nuclei (AGN), like the local galaxy Markarian 231. We investigate both possibilities. If the submillimetre-luminous galaxies are all starbursts, then we predict that the fraction of the cosmic star formation rate in these objects is large, but does not necessarily dominate the star formation rate of the Universe — the Madau plot — at any redshift. Only a few per cent by mass of the present-epoch spheroidal stellar population would have been formed in such a population of star-forming galaxies, consistent with the constraints on the number of galaxies with old stellar populations in the field at low and intermediate redshifts derived from K-band surveys. If the submillimetre-luminous galaxies are all powered by AGN, then the comoving density of supermassive black holes on to which material is accreting at high redshift probably equals no more than a few per cent of the local density of massive dark objects.

Components of the infrared celestial emission

An important parameter for cosmological studies is the extragalactic far-infrared background radiation. The question we try to answer in this paper is: Which quantitative limits can an analysis of IRAS data put on this background? The answer is not straightforward.

Further Measurements of the Submillimeter Background at Balloon Altitude

Measurements of the far-infrared background radiation were made with a balloon-borne radiometer at an altitude of 44 km. Equivalent blackbody temperatures of ${2.55}_{\ensuremath{-}0.45}^{+0.25}$, ${2.45}_{\ensuremath{-}1.05}^{+0.45}$, and ${2.75}_{\ensuremath{-}2.75}^{+0.8}$ \ifmmode^\circ\else\textdegree\fi{}K were obtained for the background radiation in bandwidths extending from 1 to 11.5, 13.5, and 18.5 ${\mathrm{cm}}^{\ensuremath{-}1}$. The total measured flux in the largest bandwidth is dominated by the atmospheric emission by ozone and water. The radiation of these atmospheric components was determined independently in a separate pair of radiometer spectral responses.

Balloon Measurements of the Far-Infrared Background Radiation

Measurements in five different passbands in the spectral region below 20 ${\mathrm{cm}}^{\ensuremath{-}1}$ have been made with a liquid-helium-cooled radiometer in two flights at approximately 40-km altitude. The equivalent temperatures are $\phantom{\rule{0ex}{0ex}}{2.7}_{\ensuremath{-}0.2}^{+0.4}$, 2.8\ifmmode\pm\else\textpm\fi{}0.2, 2.8\ifmmode\pm\else\textpm\fi{}0.2, \ensuremath{\le}2.7, \ensuremath{\le}3.4\ifmmode^\circ\else\textdegree\fi{}K in passbands of 1 to 5.4, 7.8, 7.9, 11.1, and 18.5 ${\mathrm{cm}}^{\ensuremath{-}1}$. The results are consistent with a 2.7\ifmmode^\circ\else\textdegree\fi{}K thermal radiation background. Atmospheric radiation of uncertain magnitude dominates the region above 11 ${\mathrm{cm}}^{\ensuremath{-}1}$.

Measurement of the Far-Infrared Background Radiation in the Night Sky

Measurement of the Far-Infrared Background Radiation in the Night Sky

Response :X-Rays from Centaurus A and the Far-Infrared Background Radiation

<i>Response</i> :X-Rays from Centaurus A and the Far-Infrared Background Radiation

X-Rays from Centaurus A and the Far-Infrared Background Radiation

X ray and far IR measurement inconsistency from Centaurus A, discussing metagalactic submillimeter background

Implications of the Far-Infrared Background Measurements

Some consequences of far-infrared background radiation originating beyond the solar system are derived. The most likely source, narrow emission features produced by our galaxy, can also lead to a flux from all other galaxies similar to that of the 2.7 K microwave background.

High-Energy Gamma Rays, Cosmic-Ray Electrons, and the Far-Infrared Background Radiation

It is shown that the observed flux of galactic gamma rays, which is one order of magnitude higher than the theoretical value, can be explained if one assumes the recently detected far-infrared radiation to be galactic or universal. Effects of the infrared radiation on cosmic rays are discussed.