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Session 87 - Environments of QSOs and Radio Galaxies.
Oral session, Wednesday, January 17
Corte Real, Hilton
The Arecibo Occultation radio source AO 0235+164 is a rapidly and violently variable QSO with z_e = 0.94. It was originally designated as a BL Lac object since no emission lines were detected in its spectrum; two absorption redshifts at 0.524 and 0.851 were measured some years before weak emission lines at z = 0.94 were detected by Cohen et al. (ApJ,318,577,1987). A point-like companion (Smith et al., ApJ,218,611,1977) was found 2 arc sec south with an emission line redshift at 0.524. It was designated object A by Yanny et al. (ApJ,338,735,1989). This object has sometimes been called a ``normal'' galaxy, presumably giving rise to the absorption at 0.524 in the QSO. Recent observations of the surrounding field, using the post-repair WFPC 2 on the Hubble Space Telescope, have been analyzed and the nature of the companion object 2 arc sec south, and of a second companion 1.3 arc sec east of AO, have been studied. Spectra of companion object A have been obtained with the Faint Object Spectrograph with gratings G160L and G270H, and 1.0 arc sec aperture, and these show that it is an AGN or QSO with BAL-type broad absorption lines shortward of CIV\lambda1549, SiIV\lambda1397, and NV\lambda1240, also broad CIII]\lambda1909 emission. The second object, A1, 1.3 arc sec east of the QSO, originally identified by Yanny et al. (1989) and shown to have [0II]\lambda3727 at z=0.524, is slightly extended. The physical properties and nature of this remarkable configuration will be discussed. This research has been supported in part by NASA NAS5-29293 and NAG5-1630.
Program listing for Wednesday