1995/10/03 by Smita Mathur, Martin Elvis, Mathur, Smita +4
Physics and Astronomy · #Advanced X-ray Imaging Techniques #Astrophysics (astro-ph) #Crystallography and Radiation Phenomena #FOS: Physical sciences #Nuclear Physics and Applications #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9510009
uuencoded compressed postscript file. Figure 1 not included. To appear in the Ap.J. Letters. Also available at http://hea-www.harvard.edu/QEDT/TeamPapers.html
arxiv created 1995/10/03 · openalex publication_date 1995/10/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present \it ASCA observations of the z=1.98 prototype BALQSO: PHL5200. The source was detected in both SIS and GIS. A power-law spectrum (αE = 0.6+0.9-0.6) with large intrinsic absorption (NH = 1.3+2.3-1.1 × 1023 cm-2) best describes the spectrum. Excess column density over the local Galactic value is required at the 99% confidence level. This detection suggests that, although BALQSOs are X-ray quiet, it is strong absorption in the BAL region that makes them appear faint to low energy X-ray experiments. The required intrinsic absorbing column density is two to three orders of magnitude larger than earlier estimates of column densities in BALQSOs. This implies that the BAL systems are much more highly ionized than previously thought.