X-ray emission from hot gas and XRBs in the NGC 5846 galaxy

This article presents X-ray emission characteristics of the brightest member of a G50 galaxy group NGC 5846 based on analysis of high resolution of 30 ks and 90 ks Chandra X-ray data. X-ray imaging analysis revealed the presence of 90 discrete X-ray point sources, spectral study of which depicted that the majority of them are LMXBs with a neutron star accretor. Among 90, only one source exhibits an X-ray luminosity greater than 1 0( 39) erg s( - 1) 1, exceeding the Eddington limit for a canonical mass of a neutron star and occupies a position in the hard region of the X-ray color-color plot. The cumulative X-ray luminosity function plot for all resolved XRBs exhibits a knee at L (X) = 6.6 x 10( 38) erg s (- 1) , corresponding to the Eddington limit of 2.8 solar mass neutron star. The most dominant source of the observed X-ray luminosity of NGC 5846 happens to be the diffusely distributed plasma, making its contribution up to 85% of its total value, while the contribution from resolved and unresolved point sources is up to 15%. The surface brightness distribution of the X-ray emitting gas in this galaxy exhibit structures in the form of discontinuities due to the presence of a pair of cold fronts at similar to 20 kpc. The presence of these cold fronts were confirmed in the azimuthally averaged surface brightness profile and sectorial temperature profiles and may have formed due to minor mergers. The larger values of emission line flux density ratio log([N II]H alpha) and floor in the entropy profile of the plasma collectively point toward a nonthermal ionization source of gas heating like a low-level AGN activity.