X-RAY ASTRONOMY 2019

The jet-disc connection in gamma-ray-emitting narrow-line Seyfert 1 galaxies: the X-ray view

Not scheduled

2m

Poster POSTER SESSION

Speaker

Filippo D'Ammando (Istituto Nazionale di Astrofisica (INAF))

Description

Before the launch of the Fermi satellite only two classes of AGN were known to generate relativistic jets and thus to emit up to the gamma-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The discovery by the Large Area Telescope on-board the Fermi satellite of variable gamma-ray emission from a few radio-loud narrow-line Seyfert 1 galaxies (NLSy1) revealed the presence of an emerging third class of AGN with relativistic jets. NLSy1 are usually hosted in late-type galaxies with relatively small black hole masses. This finding opened new challenging questions about the nature of these objects, the jet-disc connection, the emission mechanisms at high energies, and the formation of relativistic jets.

High quality spectra obtained by XMM-Newton are fundamental to determine if the X-ray spectrum of these sources is completely dominated by the jet emission or there is some contribution from the accretion flow, such as the soft X-ray excess and the Fe K line. NuSTAR observations provide a complementary coverage in the hard X-ray part of their spectrum.
In addition, thanks to the analysis of Swift and XMM-Newton data collected between 2008 August and 2019 March, we investigate the spectral and flux variability of gamma-ray-emitting NLSy1 on different time-scales and the connection with the gamma-ray emission observed by Fermi-LAT and the optical and UV emission observed by Swift-UVOT and XMM-OM. Moreover, the circum-nuclear environment of these NLSy1 could potentially provide a wealth of information on the radiative and mechanical feedback. Both feedback modes can be investigated through emission and absorption features arising in the X-ray spectrum. The high-resolution spectroscopic capability of XMM-Newton will be further exploited searching for such features in the spectra of gamma-ray-emitting NLSy1.

In this talk we discuss the results of the analysis of XMM-Newton, NuSTAR, and Swift data available for the nine gamma-ray-emitting NLSy1 detected by Fermi-LAT so far and we study the relation between accretion flow and jet, and the emission mechanisms at work in these NLSy1. Finally, the X-ray properties of the gamma-ray-emitting NLSy1 will be compared to what was observed in gamma-ray-emitting radio galaxies and blazars.