SIMBAD references

The quasar Q1208+1011 (z_em=3.8) is the second-highest redshift double quasar ever detected. Several indications point toward it being a gravitationally 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 in the redshift of the lensing galaxy can be obtained from an analysis of the intervening heavy-element absorption systems discovered in the QSO high-resolution spectrum. On statistical and dynamical grounds, a Mg II system present at z=1.13 appears to be 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 analysis of the proximity effect.