scholarly journals Luminosity evolution, extragalactic background light and the opacity of the Universe

1997 ◽  
Vol 291 (1) ◽  
pp. 59-64 ◽  
Author(s):  
J. I. Davies ◽  
S. Phillipps ◽  
M. Trewhella ◽  
P. Alton
Keyword(s):  
Extragalactic Background Light ◽  
Background Light ◽  
The Universe ◽  
Luminosity Evolution

scholarly journals Background Light from Population III Stars

1987 ◽  
Vol 117 ◽  
pp. 414-414
Author(s):  
Jonathan C. McDowell
Keyword(s):  
Dark Matter ◽  
Background Radiation ◽  
Large Fraction ◽  
Rest Mass ◽  
Critical Density ◽  
Density Parameter ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Far Ultraviolet ◽  
The Universe

It has been proposed (e.g. Carr, Bond and Arnett 1984) that the first generation of stars may have been Very Massive Objects (VMOs, of mass above 200 M⊙) which existed at large redshifts and left a large fraction of the mass of the universe in black hole remnants which now provide the dynamical ‘dark matter’. The radiation from these stars would be present today as extragalactic background light. For stars with density parameter Ω* which convert a fraction ϵ of their rest-mass to radiation at a redshift of z, the energy density of background radiation in units of the critical density is ΩR = εΩ* / (1+z). The VMOs would be far-ultraviolet sources with effective temperatures of 105 K. If the radiation is not absorbed, the constraints provided by measurements of background radiation imply (for H =50 km/s/Mpc) that the stars cannot close the universe unless they formed at a redshift of 40 or more. To provide the dark matter (of one-tenth closure density) the optical limits imply that they must have existed at redshifts above 25.

scholarly journals Diffuse Extragalactic Background Light versus Deep Galaxy Counts in the Subaru Deep Field: Missing Light in the Universe?

2001 ◽  
Vol 550 (2) ◽  
pp. L137-L141 ◽  
Author(s):  
Tomonori Totani ◽  
Yuzuru Yoshii ◽  
Fumihide Iwamuro ◽  
Toshinori Maihara ◽  
Kentaro Motohara
Keyword(s):  
Extragalactic Background Light ◽  
Background Light ◽  
The Universe

scholarly journals Effect of axion-like particles on the spectrum of the extragalactic gamma-ray background

2021 ◽  
Vol 2021 (11) ◽  
pp. 030
Author(s):  
Yun-Feng Liang ◽  
Xing-Fu Zhang ◽  
Ji-Gui Cheng ◽  
Hou-Dun Zeng ◽  
Yi-Zhong Fan ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Small Region ◽  
High Energy ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Very High Energy ◽  
The Universe ◽  
Very High

Abstract Axion-like particles (ALPs) provide a feasible explanation for the observed lower TeV opacity of the Universe. If the anomaly TeV transparency is caused by ALPs, then the fluxes of distant extragalactic sources will be enhanced at photon energies beyond TeV, resulting in an enhancement of the observed extragalactic gamma-ray background (EGB) spectrum. In this work, we have investigated the ALP modulation on the EGB spectrum at TeV energies. Our results show that in the most optimistic case, the existence of ALPs can cause the EGB spectrum to greatly deviate from the prediction of a pure extragalactic-background-light (EBL) absorption scenario. The deviation occurs at approximately ≳1 TeV, and the current EGB measurements by Fermi-LAT cannot identify such an effect. We also find that most of the sensitive ALP parameters have been ruled out by existing constraints, leaving only a small region of unrestricted parameters that can be probed using the EGB effect investigated in this work. Observations from forthcoming very-high-energy instruments like LHAASO and CTA may be beneficial for the study of this effect.

scholarly journals ALMA twenty-six arcmin2 survey of GOODS-S at one millimeter (ASAGAO)

2019 ◽  
Vol 15 (S352) ◽  
pp. 239-240
Author(s):  
B. Hatsukade ◽  
K. Kohno ◽  
Y. Yamaguchi ◽  
H. Umehata ◽  
Y. Ao ◽  
...  
Keyword(s):  
Archival Data ◽  
Beam Size ◽  
Density Evolution ◽  
Extragalactic Background Light ◽  
Field Surveys ◽  
Blank Field ◽  
Background Light ◽  
Luminosity Functions ◽  
Number Counts ◽  
Luminosity Evolution

AbstractThe ALMA twenty-six arcmin2 survey of GOODS-S at one millimeter (ASAGAO) is a deep (1σ ∼ 61μJy/beam) and wide area (26 arcmin2) survey on a contiguous field at 1.2 mm. By combining with archival data, we obtained a deeper map in the same region (1σ ∼ 30μJy/beam−1, synthesized beam size 0.59″ × 0.53″), providing the largest sample of sources (25 sources at 5σ, 45 sources at 4.5σ) among ALMA blank-field surveys. The median redshift of the 4.5σ sources is 2.4. The number counts shows that 52% of the extragalactic background light at 1.2 mm is resolved into discrete sources. We create IR luminosity functions (LFs) at z = 1–3, and constrain the faintest luminosity of the LF at 2 < z < 3. The LFs are consistent with previous results based on other ALMA and SCUBA-2 observations, which suggests a positive luminosity evolution and negative density evolution.

scholarly journals A New Measurement of the Hubble Constant and Matter Content of the Universe Using Extragalactic Background Light γ-Ray Attenuation

2019 ◽  
Vol 885 (2) ◽  
pp. 137 ◽  
Author(s):  
A. Domínguez ◽  
R. Wojtak ◽  
J. Finke ◽  
M. Ajello ◽  
K. Helgason ◽  
...  
Keyword(s):  
Hubble Constant ◽  
Matter Content ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Γ Ray ◽  
The Universe

scholarly journals Photon–Photon Interactions and the Opacity of the Universe in Gamma Rays

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 146
Author(s):  
Alberto Franceschini
Keyword(s):  
Gamma Rays ◽  
Personal Account ◽  
Fundamental Physics ◽  
Extragalactic Background Light ◽  
Substantial Modification ◽  
Global Coherence ◽  
Photon Interactions ◽  
Available Information ◽  
The Universe ◽  
Present Understanding

We discuss the topic of the transparency of the Universe in gamma rays due to extragalactic background light, and its cosmological and physical implications. Rather than a review, this is a personal account on the development of 30 years of this branch of physical science. Extensive analysis of the currently available information appears to us as revealing a global coherence among the astrophysical, cosmological, and fundamental physics data, or, at least, no evident need so far of substantial modification of our present understanding. Deeper data from future experiments will verify to what extent and in which directions this conclusion should be modified.

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