HST STIS Observations of PG 0946+301: the Highest Quality UV Spectrum of a BALQSO
| Autor: | Michael S. Brotherton, Richard F. Green, D. Michael Crenshaw, Vesa T. Junkkarinen, Bob Becker, Martijn de Kool, Max Pettini, Ari Laor, Smita Mathur, Paul J. Green, Sally A. Laurent-Muehleisen, Anuradha Koratkar, Bev Wills, W. N. Brandt, Norman Murray, Wil van Breugel, Nahum Arav, Wim de Vries, Kirk T. Korista |
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| Rok vydání: | 2001 |
| Předmět: | |
| DOI: | 10.48550/arxiv.astro-ph/0107414 |
| Popis: | We describe deep (40 orbits) HST/STIS observations of the BALQSO PG 0946+301 and make them available to the community. These observations are the major part of a multi-wavelength campaign on this object aimed at determining the ionization equilibrium and abundances (IEA) in broad absorption line (BAL) QSOs. We present simple template fits to the entire data set, which yield firm identifications for more than two dozen BALs from 18 ions and give lower limits for the ionic column densities. We find that the outflow's metalicity is consistent with being solar, while the abundance ratio of phosphorus to other metals is at least ten times solar. These findings are based on diagnostics that are not sensitive to saturation and partial covering effects in the BALs, which considerably weakened previous claims for enhanced metalicity. Ample evidence for these effects is seen in the spectrum. We also discuss several options for extracting tighter IEA constraints in future analyses, and present the significant temporal changes which are detected between these spectra and those taken by the HST/FOS in 1992. Comment: 32 pages, 7 figures, to appear in ApJ. See also companion paper by Arav, Korista and De Kool |
| Databáze: | OpenAIRE |
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