We present the first unambiguous evidence of a broad (Gaussian width similar to 330 eV) component of the iron K(alpha) fluorescent emission line in the X-ray obscured narrow-line Seyfert 1 galaxy, NGC 5506. This is the main result of a spectroscopic monitoring campaign on this source, performed with the XMM-Newton observatory between 2001 February and 2009 January. The broad line lacks extreme redward skewness. If modelled with a relativistic component, the profile of the line is consistent with a flat emissivity radial dependence (alpha similar or equal to 1.9). The disc inclination (similar or equal to 40 degrees) is nominally larger than typically observed in unobscured active galactic nuclei (AGNs), in agreement with most measurements of broadened iron lines in Seyfert 2 galaxies. The quality of the data allows us to decompose the full iron emission-line complex, and to study its long-term (time-scales of weeks to yr) variability pattern. The intensity of the neutral and narrow iron K(alpha) core remains constant during the monitoring campaign. This indicates that the optically thick gas responsible for the non-relativistic reprocessing of the primary AGN continuum in NGC 5506 is probably located in the torus rather than in the optical broad-line region.
Guainazzi, M., Bianchi, S., Matt, G., Dadina, M., Kaastra, J., Malzac, J., et al. (2010). Final verdict from XMM-Newton: the X-ray obscured Seyfert galaxy NGC 5506 has a broad Fe K(alpha) line RID B-4804-2010. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 406(3), 2013-2022 [10.1111/j.1365-2966.2010.16805.x].
Final verdict from XMM-Newton: the X-ray obscured Seyfert galaxy NGC 5506 has a broad Fe K(alpha) line RID B-4804-2010
MATT, Giorgio;BIANCHI, STEFANO
2010-01-01
Abstract
We present the first unambiguous evidence of a broad (Gaussian width similar to 330 eV) component of the iron K(alpha) fluorescent emission line in the X-ray obscured narrow-line Seyfert 1 galaxy, NGC 5506. This is the main result of a spectroscopic monitoring campaign on this source, performed with the XMM-Newton observatory between 2001 February and 2009 January. The broad line lacks extreme redward skewness. If modelled with a relativistic component, the profile of the line is consistent with a flat emissivity radial dependence (alpha similar or equal to 1.9). The disc inclination (similar or equal to 40 degrees) is nominally larger than typically observed in unobscured active galactic nuclei (AGNs), in agreement with most measurements of broadened iron lines in Seyfert 2 galaxies. The quality of the data allows us to decompose the full iron emission-line complex, and to study its long-term (time-scales of weeks to yr) variability pattern. The intensity of the neutral and narrow iron K(alpha) core remains constant during the monitoring campaign. This indicates that the optically thick gas responsible for the non-relativistic reprocessing of the primary AGN continuum in NGC 5506 is probably located in the torus rather than in the optical broad-line region.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
