Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-02-03
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted by A&A. 12 pages, 8 figures. Added references and corrected typos
Scientific paper
Broad absorption line quasars (BALQSOs) are key objects for studying the structure and emission/absorption properties of AGN. However, despite their fundamental importance, the properties of BALQSOs are still not well understood. In order to investigate the X-ray nature of these sources, as well as the correlations between X-ray and rest-frame UV properties, we compile a large sample of 88 BALQSOs observed by XMM-Newton. We performed a full X-ray spectral analysis on a sample of 39 sources with higher X-ray spectral quality, and an approximate HR analysis on the remaining sources. Using available optical spectra, we calculate the BALnicity index and investigate the dependence between this optical parameter and different X-ray properties. Using the neutral absorption model, we found that 36% of our BALQSOs have NH < 5x10^21 cm^-2, lower than the expected X-ray absorption for such objects. However, when we used a physically-motivated model for the X-ray absorption in BALQSOs, i.e. ionized absorption, \sim 90% of the objects are absorbed. The absorption properties also suggest that LoBALs may be physically different objects from HiBALs. In addition, we report on a correlation between the ionized absorption column density and BAL parameters. There is evidence (at 98% level) that the amount of X-ray absorption is correlated with the strength of high-ionization UV absorption. This correlation, not previously reported, can be naturally understood in virtually all BALQSO models, as driven by the total amount of gas mass flowing towards the observer.
Barcons Xavier
Carrera Francicso J.
Gil-Merino Rodrigo
Streblyanska A.
No associations
LandOfFree
A revision of the X-ray absorption nature of the BALQSOs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A revision of the X-ray absorption nature of the BALQSOs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A revision of the X-ray absorption nature of the BALQSOs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-602070