On the Host Galaxy of GRB 150101B and the Associated Active Galactic Nucleus

TL;DR

This study identifies the first known GRB host galaxy containing an active galactic nucleus (AGN), revealing a massive elliptical galaxy with an old stellar population and a likely radiatively inefficient accretion flow, linking GRB and AGN activities.

Contribution

It reports the discovery of an AGN in a GRB host galaxy, providing new insights into the host environment and potential interactions between GRB and AGN activities.

Findings

Host galaxy contains a low-luminosity AGN confirmed by SED modeling.

The galaxy is a massive elliptical with an old stellar population (~5.7 Gyr).

The AGN is likely powered by a radiatively inefficient accretion flow.

Abstract

We present a multi-wavelength analysis of the host galaxy of short-duration gamma-ray burst (GRB) 150101B. Follow-up optical and X-ray observations suggested that the host galaxy, 2MASX J12320498-1056010, likely harbors a low-luminosity active galactic nuclei (AGN). Our modeling of the spectral energy distribution (SED) has confirmed the nature of the AGN, making it the first reported GRB host that contains an AGN. We have also found the host galaxy is a massive elliptical galaxy with stellar population of $\sim 5.7\ Gyr$, one of the oldest among the short-duration GRB hosts. Our analysis suggests that the host galaxy can be classified as an X-ray bright, optically normal galaxy (XBONG), and the central AGN is likely dominated by a radiatively inefficient accretion flow (RIAF). Our work explores interesting connection that may exist between GRB and AGN activities of the host galaxy, which can help understand the host environment of the GRB events and the roles of AGN feedback.