X-Ray Emission from a prominent dust lane lenticular galaxy NGC 5866

TL;DR

This study investigates the X-ray emission characteristics of NGC 5866, revealing contributions from diffuse hot gas and X-ray binaries, and examines the galaxy's dust properties and their relation to the interstellar medium.

Contribution

It provides detailed analysis of the X-ray sources, diffuse emission, and dust grain properties in NGC 5866, highlighting the nature of its X-ray binary population and dust grain size differences.

Findings

22 discrete X-ray sources detected within the galaxy.

Diffuse X-ray emission modeled by thermal plasma plus power law.

Dust grains are smaller than those in the Milky Way.

Abstract

We report the multiband imagery with an emphasis on the X-ray emission properties of a prominent dust lane lenticular galaxy NGC 5866. X-ray emission from this galaxy is due to a diffuse component and a substantial contribution from the population of discrete X-ray binary sources. A total of 22 discrete sources have been detected within the optical D25 extent of the galaxy, few of which exhibit spatial association with the globular clusters hosted by this system. Composite spectrum of the diffuse emission from this galaxy was well constrained by a thermal plasma model plus a power law component to represent the emission from unresolved sources, while that of the discrete sources was well fitted by an absorbed power law component of photon index 1.82$\pm$0.14. X-ray color-color plot for the resolved source was used to classify the detected sources. The cumulative X-ray luminosity function of the XRBs is well represented by a power law function of index of {\Gamma} ~ 0.82$\pm$0.12. Optical imagery of NGC 5866 revealed a prominent dust lane along the optical major axis of the host with dust extinction properties similar to those of the canonical grains in the Milky Way. The dust grains responsible for the extinction of starlight in NGC 5866 are relatively smaller in size when compared with the canonical grains in the Milky Way and high energetic charged particles seems to be responsible for the modulation of the dust grain size. Spatial correspondence is evident between the dust and other phases of ISM.