The object B1422+231 is a quadruply imaged QSO with an exceptionally large lensing contribution from group galaxies other than main lensing galaxy. We have detected diffuse X-rays from the galaxy group in archival Chandra observations; the inferred temperature is consistent with the published velocity dispersion. We explore the range of possible mass maps that would be consistent with the observed image positions, radio fluxes, and ellipticities. Under plausible but not very restrictive assumptions about the lensing galaxy, predicted time delays involving the faint fourth image are fairly well constrained around 7 h(-1) days.
- gravitational lensing
- quasars : individual (B1422+231)