A (likely) X-ray jet from NGC6217 observed by XMM–Newton

Abstract

NGC6217 is a nearby spiral galaxy with a starburst region near its center. Evidence for a low luminosity Active Galactic Nucleus (AGN) in its core has also been found in optical spectra. Intriguingly, X-ray observations by ROSAT revealed three knots aligned with the galaxy center, resembling a jet structure. This paper presents a study of XMM-Newton observations made to assess the hypothesis of a jet emitted from the center of NGC6217. The XMM data confirm the knots found with ROSAT and our spectral analysis shows that they have similar spectral properties with a hard photon index Γ ∼ 1.7. The core of NGC6217 is well fitted by a model with an AGN and a starburst component, where the AGN contributes at most 46% of the total flux. The candidate jet has an apparent length ∼ 15 kpc and a luminosity of ∼ 5 × 10 38 erg s −1 . It stands out by being hosted by a spiral galaxy, since jets are more widely associated with ellipticals. To explain the jet launching mechanism we consider the hypothesis of an advection dominated accretion flow with a low accretion rate. The candidate jet emitted from NGC6217 is intriguing since it represents a challenge to the current knowledge of the connection between AGN, jets and host galaxies.

Unveiling the 100 pc scale nuclear radio structure of NGC 6217 with e-MERLIN and the VLA

“…a barred spiral galaxy with an inner and outer (pseudo-) ring structure and with a star formation rate of ∼2.9 M per year (James et al 2004;Knapen & James 2009). Different authors classify the nuclear region in NGC 6217 variably as a Seyfert 2 (Cabrera-Lavers & Garzón 2004), H II Region (Ho et al 1997a;Véron-Cetty & Véron 2006) or a LINER (Nicholson et al 1997;Falocco et al 2017). The exact nuclear classification is important for understanding the ionisation mechanisms in the nucleus: Seyferts are ionised by an AGN, whereas H II regions are ionised through SF processes.…”