MYTorus Examples

MYTorus can emulate non-toroidal geometries. The MYTorus model can emulate geometries other than toroidal by applying the model in different modes. The model allows for the first time to deduce two column densities for obscured AGN, not just one (corresponding to the line-of-sight column density, and a global “average” column density). This cannot be done with standard disk-reflection models (because the column density for reflection is assumed to be infinite), or other X-ray reprocessor models (which do not allow decoupling of the unscattered and scattered continuum components). In some cases the MYTorus model can reveal if the obscuring matter is required to be clumpy (see the case for NGC 4945 below).

Independence of the direct and scattered continua. Decoupling of the line-of-sight and global column densities is also important for taking into account continuum variability and time-delays between the direct (zeroth-order, or unscattered) continuum and the Compton-scattered continuum. No other spectral-fitting model of the obscuring matter distribution in AGN, including the models of Brightman and Nandra (2011) currently has this capability.

Finte column-density effects. We are finding that the column density in and out of the line-of-sight can be very different in some AGN, and that the Compton-thin reflection plays an important role in the X-ray spectrum. A Compton-thin reflection continuum can even be the dominant continuum component somewhere between 2 to 4 keV, depending on the global column density. Disk-reflection models miss this component and the curvature due to Compton-thin reflection can easily be mistaken for other features such as broad Fe K line. All in all, a richer variety of X-ray spectra can be produced by realistic reprocessor models compared to the ad hoc disk-reflection models. Examples of the different types of X-ray spectra can easily be found in real data and the results of fitting the MYTorus model to some AGN which illustrate that variety are listed below. Plots and details for each fit can be found by following the links below.

NGC 4507 (Suzaku data)
Nearly Compton-thick in the line-of-sight, Compton-thin out of the line-of-sight.

NGC 4388 (Suzaku data)
Globally Compton-thin.

Mkn 3 (Suzaku data)
Nearly Compton-thick in the line-of-sight, Compton-thin out of the line-of-sight.

Circinus galaxy (Suzaku data)
Compton-thick, observed in reflection, no obscuration in line-of-sight.

NGC 4945 (Suzaku data)
Compton-thick globally and in line-sight.

NGC 4388, Mkn 3, Circinus galaxy, NGC 4945 spectral fits all shown together for direct comparison.

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