Observations of the new gravitational lens system UM 673 = Q 0142-100

Abstract

The authors have recently initiated a high resolution direct imaging survey of a selected sample of highly luminous quasars (HLQs). The observations are carried out with the 2.2 m telescope at ESO, and with the VLA at the NRAO, New Mexico. Following the first observing run at ESO, the authors have reported the discovery of a new gravitational lens system for the HLQ UM 673 = Q 0142-100. Additional observations supporting this interpretation are discussed here. Application of gravitational optometry to this system is given: a value of M[SUB]0[/SUB] = 2.4×10[SUP]11[/SUP]M_sun; is derived for the mass of the lensing galaxy located between UM 673 A and B and a most likely estimate of Deltat = 7 weeks is found for the expected delay between the arrival times of a similar variability event in the two lensed images of the quasar (H[SUB]0[/SUB] = 75 km s[SUP]-1[/SUP]Mpc[SUP]-1[/SUP], q[SUB]0[/SUB] = 0)