EMISSION-LINES FROM COMPANION GALAXIES OF QSOS

Anticipating new spectroscopic studies of quasar companions, we calcul ate expected emission-line spectra for the companion galaxies. Under t he assumption of isotropic photoionizing radiation, we predict equival ent widths for H alpha, H beta, [O III] lambda 5007, [O II] lambda 372 7, [Ne III] lambda 3869, and Mg II lambda 2798 lines. We consider six quasars, two of which (PKS 2135 - 14 and PKS 2349 - 014) have very clo se companions with projected separation less than 4 h(-1) kpc. For the se companions the calculated emission lines should be easily observabl e, with W-lambda greater than or similar to 20 Angstrom for the [O III ], [O II], and H alpha lines. The presence of strong emission lines fr om the companions occupying only a tiny solid angle would suggest that (1) quasar radiation is isotropic; (2) companion galaxies have measur able amounts of gas, which can be assessed using the photoionization m odels; (3) host galaxies, if present, have been depleted of gas or do not interact with the companions.