Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy

Details Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy

2011-02-22

arxiv.org/abs/1102.4621v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Accepted to ApJ. 6 pages, 2 figures

Scientific paper

We present Subaru/FOCAS spectropolarimetry of two active galaxies in the Cosmic Evolution Survey. These objects were selected to be optically dull, with the bright X-ray emission of an AGN but missing optical emission lines in our previous spectroscopy. Our new observations show that one target has very weak emission lines consistent with an optically dull AGN, while the other object has strong emission lines typical of a host-diluted Type 2 Seyfert galaxy. In neither source do we observe polarized emission lines, with 3-sigma upper limits of P_BLR < 2%. This means that the missing broad emission lines (and weaker narrow emission lines) are not due to simple anisotropic obscuration, e.g., by the canonical AGN torus. The weak-lined optically dull AGN exhibits a blue polarized continuum with P = 0.78 +/- 0.07% at 4400 A < lambda_rest < 7200 A (P = 1.37 +/- 0.16% at 4400 A < lambda_rest < 5050 A). The wavelength dependence of this polarized flux is similar to that of an unobscured AGN continuum and represents the intrinsic AGN emission, either as synchrotron emission or the outer part of an accretion disk reflected by a clumpy dust scatterer. Because this intrinsic AGN emission lacks emission lines, this source is likely to have a radiatively inefficient accretion flow.

Affiliated with

Also associated with

No associations

Rating

Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy 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 Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-173990