Open AccessCosmological implications of APM 08279+5255, an old quasar at z = 3.91
Author(s) -
Alcaniz J. S.,
Lima J. A. S.,
Cunha J. V.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06553.x
Subject(s) - physics , astrophysics , dark energy , cosmic microwave background , quasar , quintessence , redshift , age of the universe , universe , cosmological constant , hubble's law , astronomy , equation of state , supernova , cosmology , galaxy , theoretical physics , quantum mechanics , anisotropy
The existence of old high‐redshift objects provides an important tool for constraining the expanding age of the Universe and the formation epoch of the first objects. In a recent paper, Hasinger, Schartel & Komossa reported the discovery of the quasar APM 08279 + 5255 at redshift z = 3.91 with an extremely high iron abundance, and estimated age of 2–3 Gyr. By assuming the lower limit for this age estimate and the latest measurements of the Hubble parameter as given by the HST key project, we study some cosmological implications from the existence of this object. In particular, we derive new limits on the dark matter and vacuum energy contribution. Our analysis is also extended to quintessence scenarios in which the dark energy is parametrized by a smooth component with an equation of state p x =ω x ρ x (−1 ≤ω x < 0) . For flat models with a relic cosmological constant we show that the vacuum energy density parameter is constrained to be Ω Λ ≥ 0.78 , a result that is marginally compatible with recent observations from type Ia supernovae (SNe Ia) and cosmic microwave background (CMB). For quintessence scenarios the same analysis restricts the cosmic parameter to ω x ≤−0.22 . Limits on a possible first epoch of quasar formation are also briefly discussed. The existence of this object pushes the formation era back to extremely high redshifts.