Mass determination of groups of galaxies: Effects of the cosmological constant
| Autor: | S. Peirani, J. A. de Freitas Pacheco |
|---|---|
| Přispěvatelé: | Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2006 |
| Předmět: |
FOS: Physical sciences
Astrophysics::Cosmology and Extragalactic Astrophysics Cosmological constant Astrophysics 98.62.Ck 98.65.Bv 98.65.Cw 01 natural sciences [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] Thermodynamics of the universe symbols.namesake 0103 physical sciences Peculiar velocity 010303 astronomy & astrophysics Instrumentation Astrophysics::Galaxy Astrophysics Physics Hubble constant [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] 010308 nuclear & particles physics Equation of state (cosmology) Astrophysics (astro-ph) Velocity dispersion Astronomy and Astrophysics Virgo Cluster Space and Planetary Science Local Group symbols Dark energy Hubble's law |
| Zdroj: | New Astronomy New Astronomy, Elsevier, 2006, 11, pp.325-330. ⟨10.1016/j.newast.2005.08.008⟩ |
| ISSN: | 1384-1076 |
| DOI: | 10.1016/j.newast.2005.08.008 |
| Popis: | The spherical infall model first developed by Lema\^{i}tre and Tolman was modified in order to include the effects of a dark energy term. The resulting velocity-distance relation was evaluated numerically. This equation, when fitted to actual data, permits the simultaneous evaluation of the central mass and of the Hubble parameter. Application of this relation to the Local Group, when the dark energy is modeled by a cosmological constant, yields a total mass for the M31-Milky Way pair of (2.5 +/- 0.7) x 10^12 M\_sun, a Hubble parameter H\_0 = 74 +/- 4 km s^-1 Mpc^-1 and a 1-D velocity dispersion for the flow of about 39 km s^-1. The zero-velocity and the marginally bound surfaces of the Local Group are at about 1.0 and 2.3 Mpc respectively from the center of mass. A similar analysis for the Virgo cluster yields a mass of (1.10 +/- 0.12) x 10^15 M\_sun and H\_0 = 65 +/- 9 km s^-1 Mpc^-1. The zero-velocity is located at a distance of 8.6 +/- 0.8 Mpc from the center of the cluster. The predicted peculiar velocity of the Local Group towards Virgo is about 190 kms^-1, in agreement with other estimates. Slightly lower masses are derived if the dark energy is represented by a fluid with an equation of state P = w\epsilon with w = -2/3. Comment: 13 pages, 3 figures. Version to appear in New Astronomy. Typing errors corrected in relation (1) and in percentage value in page 5 |
| Databáze: | OpenAIRE |
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