The Gravitational Lensing in the QSO 1208+10 from the Proximity Effect in its Lyman alpha Forest

Abstract

The quasar Q1208+1011 (z_{em}=3.8) is the second highest redshift double quasar ever detected. Several indications point toward it being a gravitational lensed system, although a definitive proof is still lacking. We present new evidence of its lensed nature based on the weakness of the ``proximity effect'' measured in the high resolution Lyman absorption spectrum of the QSO. A luminosity amplification as large as 22 has been derived from this analysis. Indications on the redshift of the lensing galaxy can be obtained from the analysis of the intervening heavy element absorption systems discovered in the QSO high resolution spectrum. On statistical and dynamical grounds a MgII system present at z=1.13 appears as the most likely candidate for the lensing galaxy. We compare the observed parameters with a simple isothermal model for the lens to derive the properties of the lensing galaxy. The resulting magnification factor is smaller, although marginally consistent with that derived by the analysis of the proximity effect.

11 pages, 2 Postscript figures, ApJ in press

References in corpus (2)

• The Redshift Evolution of the Lyman Alpha Forest
• Q1208+1011: Search for the lensing galaxy

Cited by in corpus (5)

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• X-ray Observations of Gravitationally Lensed Quasars; Evidence for a Hidden Quasar Population
• Exploratory Study of the X-Ray Properties of Quasars With Intrinsic Narrow Absorption Lines
• Constraining the Gravitational Lensing of $z\gtrsim 6$ Quasars from their Proximity Zones