Black Hole Powered Nebulae and a Case Study of the Ultraluminous X-ray Source IC342 X-1

TL;DR

This study investigates the nebulae associated with ultraluminous X-ray sources, especially IC342 X-1, using multi-wavelength observations to understand their energetics, morphology, and the nature of their central black holes.

Contribution

It presents new radio and optical observations of ULX nebulae, estimates the black hole mass in IC342 X-1, and discusses nebula energetics within bubble theory, highlighting jet-related inflation.

Findings

Detected a radio nebula associated with IC342 X-1.

Estimated the black hole mass in IC342 X-1 as less than 1000 solar masses.

Analyzed nebula energetics and suggested jet inflation for IC342 X-1.

Abstract

We present new radio, optical, and X-ray observations of three Ultraluminous X-ray sources (ULXs) that are associated with large-scale nebulae. We report the discovery of a radio nebula associated with the ULX IC342 X-1 using the Very Large Array (VLA). Complementary VLA observations of the nebula around Holmberg II X-1, and high-frequency Australia Telescope Compact Array (ATCA) and Very Large Telescope (VLT) spectroscopic observations of NGC5408 X-1 are also presented. We study the morphology, ionization processes, and the energetics of the optical/radio nebulae of IC342 X-1, Holmberg II X-1 and NGC5408 X-1. The energetics of the optical nebula of IC342 X-1 is discussed in the framework of standard bubble theory. The total energy content of the optical nebula is 6 x 10^52 erg. The minimum energy needed to supply the associated radio nebula is 9.2 x 10^50 erg. In addition, we detected an unresolved radio source at the location of IC342 X-1 at VLA scales. However, our Very Long Baseline Interferometry (VLBI) observations using the European VLBI Network likely rule out the presence of any compact radio source at milli-arcsecond (mas) scales. Using a simultaneous Swift X-ray Telescope measurement, we estimate an upper limit on the mass of the black hole in IC342 X-1 using the "fundamental plane" of accreting black holes and obtain M_BH < (1.0\pm0.3) x 10^3 M_Sun. Arguing that the nebula of IC342 X-1 is possibly inflated by a jet, we estimate accretion rates and efficiencies for the jet of IC342 X-1 and compare with sources like S26, SS433, IC10 X-1.