Measuring Column Densities in Quasar Outflows: VLT Observations of QSO 2359-1241

Details Measuring Column Densities in Quasar Outflows: VLT Observations of QSO 2359-1241 Measuring Column Densities in Quasar Outflows: VLT Observations of QSO 2359-1241

2008-07-01

arxiv.org/abs/0807.0228v1

Astrophys.J.681:954-964,2008

Astronomy and Astrophysics

Astrophysics

27 pages, 6 figures, to appear on ApJ Jul 10. The full (online) version of figure 2 can be obtained here: http://www.phys.vt

Scientific paper

10.1086/588651

We present high resolution spectroscopic VLT observations of the outflow seen in QSO 2359-1241. These data contain absorption troughs from five resonance Fe II lines with a resolution of ~7 km/s and signal-to-noise ratio per resolution element of order 100. We use this unprecedented high quality data set to investigate the physical distribution of the material in front of the source, and by that determine the column densities of the absorbed troughs. We find that the apparent optical depth model gives a very poor fit to the data and greatly underestimates the column density measurements. Power-law distributions and partial covering models give much better fits with some advantage to power-law models, while both models yield similar column density estimates. The better fit of the power-law model solves a long standing problem plaguing the partial covering model when applied to large distance scale outflow: How to obtain a velocity dependent covering factor for an outflow situated at distances thousands of time greater than the size of the AGN emission source. This problem does not affect power-law models. Therefore, based on the better fit and plausibility of the physical model, we conclude that in QSO 2359-1241, the outflow covers the full extent of the emission source but in a non-homogeneous way.

Affiliated with

Also associated with

No associations

Rating

Measuring Column Densities in Quasar Outflows: VLT Observations of QSO 2359-1241 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 Measuring Column Densities in Quasar Outflows: VLT Observations of QSO 2359-1241, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measuring Column Densities in Quasar Outflows: VLT Observations of QSO 2359-1241 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-421471