AAS 195th Meeting, January 2000
Session 18. QSO Absorption Lines
Display, Wednesday, January 12, 2000, 9:20am-6:30pm, Grand Hall

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[18.02] On the Origin of Intrinsic UV Narrow Absorption Lines in Low-Redshift QSOs II.: A Multiwavelength Analysis

R. Ganguly, N.A. Bond, J.C. Charlton, M. Eracleous, W.N. Brandt, C.W. Churchill (Penn State)

From a sensitive survey of associated narrow absorption lines (NALs) in the low-redshift HST Quasar Absorption Line Key Project sample of QSOs, we attempt to uncover the underlying cause of intrinsic NALs and gain insight into the physical mechanism behind the production of NAL gas. From other studies, we have clues as to what QSO properties may be relevant. High-redshift studies of radio-selected QSO samples (Foltz et al.~1986, Anderson et al.~1987) have shown a clear excess of strong CIV-selected systems within {5000~km/s} of the QSO emission redshift. However, optically-selected samples at similar redshifts (Sargent et al.~1988, Sargent et al.~1989) have shown no excess. In an intermediate redshift survey of associated MgII absorption, Aldcroft et al.~(1994) speculated that NALs appeared in optically faint, steep radio spectrum QSOs. From X-ray studies of low-redshift QSOs and Seyfert 1s (Brandt et al.~1999, Crenshaw et al.~1999), there is also a connection between the strength of CIV absorption and the weakness of the soft X-ray spectrum. There are indications that the strength of NALs is related to the properties of the host QSO, but the exact relationship is complicated.

We compile multiwavelength data (radio, optical, and X-ray) for each QSO and report the results of multivariate statistical tests on the sample. We calculate luminosities and spectral indices at rest-frame 5GHz, 2500Å, and 2keV using fluxes found from online catalogs (e.g. NVSS, FIRST, RASS) and supplemented from the literature (e.g. Jannuzi et al.~1998, Tananbaum et al.~1986). We also include in the analysis the radio morphology (the 5GHz core-to-lobe flux ratio) and the kinematics of the broad line region (the CIV FWHM). We approach the multivariate analysis from two points of view - one in which NALs populate a distinct class of QSO and another in which the NAL strength is a continuous property related to an underlying physical parameter.

If you would like more information about this abstract, please follow the link to http://www.astro.psu.edu/users/cwc/qsogroup/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract: ganguly@astro.psu.edu

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