Universe opacity and EBL

0464773 - GFÚ 2018 RIV GB eng J - Článek v odborném periodiku
Vavryčuk, Václav
Universe opacity and EBL.
Monthly Notices of the Royal Astronomical Society. Roč. 465, č. 2 (2017), s. 1532-1542. ISSN 0035-8711. E-ISSN 1365-2966
Institucionální podpora: RVO:67985530
Klíčová slova: cosmic background radiation * dust, extinction * early Universe * galaxies: high redshift * galaxies: ISM * intergalactic medium
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.194, rok: 2017

The observed extragalactic background light (EBL) is affected by light attenuation due to absorption of light by galactic and intergalactic dust in the Universe. Even galactic opacity of 10-20 per cent and minute universe intergalactic opacity of 0.01 mag h Gpc(-1) at the local Universe have a significant impact on the EBL because obscuration of galaxies and density of intergalactic dust increase with redshift as (1 + z)(3). Consequently, intergalactic opacity increases and the Universe becomes considerably opaque at z > 3. Adopting realistic values for galactic and intergalactic opacity, the estimates of the EBL for the expanding dusty universe are close to observations. The luminosity density evolution fits well measurements. The model reproduces a steep increase of the luminosity density at z < 2, its maximum at z = 2-3, and its decrease at higher redshifts. The increase of the luminosity density at low z is not produced by the evolution of the star formation rate but by the fact that the Universe occupied a smaller volume in previous epochs. The decline of the luminosity density at high z originates in the opacity of the Universe. The calculated bolometric EBL ranges from 100 to 200 nW m(-2) sr(-1) and is within the limits of 40 and 200 nW m(-2) sr(-1) of current EBL observations. The model predicts 98 per cent of the EBL coming from radiation of galaxies at z < 3.5. Accounting for light extinction by intergalactic dust implies that the Universe was probably more opaque than dark for z > 3.5.
Trvalý link: http://hdl.handle.net/11104/0263546