The external shear acting on gravitational lens B1422+231

Tomislav Kundić, David W. Hogg, Roger D. Blandford, Judith G. Cohen, Lori M. Lubin, James E. Larkin

    Research output: Contribution to journalArticlepeer-review


    In a number of multiply imaged quasar systems, a significant contribution to the lensing potential is provided by groups and clusters of galaxies associated with the primary lens. As part of an ongoing effort to gather observational data on these systems, we present spectroscopy and near-infrared and optical photometry of galaxies in the field of the quadruple lens system B1422+231. The spectra show that the primary lens and five nearby galaxies belong to a compact group at z = 0.338. The median projected radius of this group is 35h-1 kpc and its velocity dispersion is ∼550 km s-1. A straightforward application of the virial theorem yields a group mass of 1.4× 1013h-1M, which provides sufficient external shear to produce the observed image configuration. This data rules out a class of models and improves the system's prospects for a measurement of the Hubble constant.

    Original languageEnglish (US)
    Pages (from-to)2276-2283
    Number of pages8
    JournalAstronomical Journal
    Issue number6
    StatePublished - Dec 1997

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science


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