Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-10-06
Astronomy and Astrophysics
Astrophysics
aastex (V4), 4 eps figures. Accepted by ApJ
Scientific paper
10.1086/308416
We report infrared spectroscopy of the prototypical Seyfert 2 galaxy NGC 1068, aiming at detection of broad components of hydrogen recombination lines that originate in the obscured broad-line region. Using the Short Wavelength Spectrometer on board the Infrared Space Observatory, we have observed for the first time the regions of Brackett beta 2.626um and Pfund alpha 7.460um, and present improved data for Brackett alpha 4.052um. No significant broad components are detected, implying an equivalent visual extinction to the broad-line region of at least 50 magnitudes and an obscuring column density of at least 10^23 cm^-2. While consistent with a highly obscured broad-line region, as required by the classical unified scenario, these limits are not yet significant enough to discriminate strongly between different torus models or to constrain properties of the gas causing the very large X-ray obscuration. We discuss the systematic limitations of infrared broad-line region searches and suggest that Brackett alpha may often be the most favorable transition for future searches.
Alexander Tal
Awaki Hisamitsu
Fosbury Robert A. E.
Fricke Klaus
Genzel Reinhard
No associations
LandOfFree
A search for broad infrared recombination lines in NGC 1068 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 search for broad infrared recombination lines in NGC 1068, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A search for broad infrared recombination lines in NGC 1068 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-528512