The host galaxy of the gamma-ray-emitting narrow-line Seyfert 1 galaxy PKS 1502+036

TL;DR

This study uses near-infrared imaging to analyze the host galaxy of the gamma-ray-emitting NLSy1 PKS 1502+036, revealing an elliptical galaxy with a massive black hole, challenging previous ideas about jet formation.

Contribution

It provides detailed imaging evidence that gamma-ray-emitting NLSy1 galaxies host massive black holes in elliptical galaxies, suggesting a different jet formation mechanism than previously thought.

Findings

Host galaxy is an elliptical with a Sersic index of 3.5.

Black hole mass estimated at about 7 x 10^8 solar masses.

Relativistic jets likely originate from massive black holes in elliptical hosts.

Abstract

The detection of gamma-ray emission from narrow-line Seyfert 1 galaxies (NLSy1) has challenged the idea that large black hole (BH) masses ($\ge$10$^8$ M$_{\odot}$) are needed to launch relativistic jets. We present near-infrared imaging data of the gamma-ray-emitting NLSy1 PKS 1502+036 obtained with the Very Large Telescope. Its surface brightness profile, extending to $\sim$ 20 kpc, is well described by the combination of a nuclear component and a bulge with a Sersic index $n$ = 3.5, which is indicative of an elliptical galaxy. A circumnuclear structure observed near PKS 1502+036 may be the result of galaxy interactions. A BH mass of about $\sim 7 \times 10^{8}$ M$_{\odot}$ has been estimated by the bulge luminosity. The presence of an additional faint disc component cannot be ruled out with the present data, but this would reduce the BH mass estimate by only $\sim$ 30%. These results, together with analogous findings obtained for FBQS J1644+2619, indicate that the relativistic jets in gamma-ray-emitting NLSy1 are likely produced by massive black holes at the center of elliptical galaxies.