The baryon density at z = 0.9–1.9
| العنوان: | The baryon density at z = 0.9–1.9 |
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| المؤلفون: | Dieter Reimers, E. Janknecht, Cora Fechner, N. Prause |
| المصدر: | Astronomy & Astrophysics. 470:67-72 |
| بيانات النشر: | EDP Sciences, 2007. |
| سنة النشر: | 2007 |
| مصطلحات موضوعية: | Physics, Astrophysics (astro-ph), FOS: Physical sciences, Warm–hot intergalactic medium, Astronomy and Astrophysics, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, Redshift, Baryon, Space and Planetary Science, Ionization, Intergalactic travel, Astrophysics::Galaxy Astrophysics, Background radiation |
| الوصف: | We present an analysis of the Lyman alpha forests of five quasar spectra in the near UV. Properties of the intergalactic medium (IGM) at an intermediate redshift interval (0.9 < z < 1.9) are studied. The amount of baryons in the diffuse photoionised IGM and the warm-hot intergalactic medium (WHIM) are traced to get constraints on the redshift evolution of the different phases of the intergalactic gas. The baryon density of the diffuse IGM is determined with photoionisation calculations under the assumption of local hydrostatic equilibrium. We assume that the gas is ionised by a metagalactic background radiation with a Haardt & Madau (2001) spectrum. The WHIM is traced with broad Lyman alpha (BLA) absorption. The properties of a number of BLA detections are studied. Under the assumption of collisional ionisation equilibrium a lower limit to the baryon density could be estimated. It is found that the diffuse photoionised IGM contains at least 25% of the total baryonic matter at redshifts 1 < z < 2. For the WHIM a lower limit of 2.4% could be determined. Furthermore the data indicates that the intergalactic gas is in a state of evolution at z=1.5. We confirm that a considerable part of the WHIM is created between z=1 and z=2. 6 pages, 1 figure, accepted for publication in A&A |
| تدمد: | 1432-0746 0004-6361 |
| DOI: | 10.1051/0004-6361:20077283 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b297ce0d8ee3a9f9f5ce376ec726da72 https://doi.org/10.1051/0004-6361:20077283 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....b297ce0d8ee3a9f9f5ce376ec726da72 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14320746 00046361 |
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| DOI: | 10.1051/0004-6361:20077283 |