Elucidating the global distribution of reprocessing gas in NGC 1194
Abstract
A joint XMM-Newton and NuSTAR observation was conducted for the bright, local Seyfert 1.9 galaxy, NGC 1194. The hard spectral form of this active galactic nucleus (AGN) was modelled using the toroidal reprocessor MYTORUS. The decoupled model form provides a good description of the spectrum, with reflection arising from gas with a global average column density >4 × 1024 cm-2 and transmission of the continuum through an order-of-magnitude lower column. In this model, the reflection strength is a factor of ~3 higher than expected from a simple torus. Such a result may indicate that much of the intrinsic X-ray continuum is hidden from view. An alternative model is that of a patchy torus, where 85 per cent of sightlines are obscured by Compton-thick gas and the remaining 15 per cent by Compton-thin gas. The patchy torus model is based on a solar abundance of Fe and is consistent with X-ray partial-covering results found in other AGN. That a patchy torus model would relieve the issue with the strength of the reflection signature is not an intuitive result: such an insight regarding the geometry of the global reprocessing gas could not have been obtained using ad hoc model components to describe the spectral form.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2020
- DOI:
- 10.1093/mnras/staa2401
- arXiv:
- arXiv:2007.04366
- Bibcode:
- 2020MNRAS.498.1983T
- Keywords:
-
- galaxies:active;
- galaxies: individual: NGC 1194;
- galaxies: Seyfert;
- X-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 10 pages, accepted by MNRAS