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 th...

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Main Authors: Kyadampure Anil, Vagshette Nilkanth, Patil Madhav
Format: Article
Language:English
Published: De Gruyter 2025-01-01
Series:Open Astronomy
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Online Access:https://doi.org/10.1515/astro-2024-0008
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author Kyadampure Anil
Vagshette Nilkanth
Patil Madhav
author_facet Kyadampure Anil
Vagshette Nilkanth
Patil Madhav
author_sort Kyadampure Anil
collection DOAJ
description 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 1039ergs−11{0}^{39}\hspace{0.33em}{\rm{erg}}\hspace{0.33em}{{\rm{s}}}^{-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 LX=6.6×1038ergs−1{L}_{X}=6.6\times \hspace{0.33em}1{0}^{38}\hspace{0.33em}{\rm{erg}}\hspace{0.33em}{{\rm{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 ∼20 \sim 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]Hα\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.
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issn 2543-6376
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spelling doaj-art-cff900a575604f5b883e05259dbdc66b2025-02-02T15:44:43ZengDe GruyterOpen Astronomy2543-63762025-01-013419711210.1515/astro-2024-0008X-ray emission from hot gas and XRBs in the NGC 5846 galaxyKyadampure Anil0Vagshette Nilkanth1Patil Madhav2Department of Physics, Sanjeevanee Mahavidyalaya, Chapoli, Tq.Chakur Dist. Latur-413 513, IndiaDepartment of Physics and Electronics, Maharashtra Udayagiri Mahavidyalaya, Udgir Dist., Latur-413 517, IndiaSchool of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded-431 606, IndiaThis 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 1039ergs−11{0}^{39}\hspace{0.33em}{\rm{erg}}\hspace{0.33em}{{\rm{s}}}^{-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 LX=6.6×1038ergs−1{L}_{X}=6.6\times \hspace{0.33em}1{0}^{38}\hspace{0.33em}{\rm{erg}}\hspace{0.33em}{{\rm{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 ∼20 \sim 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]Hα\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.https://doi.org/10.1515/astro-2024-0008galaxies:generalgalaxies:ellipticalgalaxies:individual ngc 5846x-rays:galactic mediumx-rays:binaries
spellingShingle Kyadampure Anil
Vagshette Nilkanth
Patil Madhav
X-ray emission from hot gas and XRBs in the NGC 5846 galaxy
Open Astronomy
galaxies:general
galaxies:elliptical
galaxies:individual ngc 5846
x-rays:galactic medium
x-rays:binaries
title X-ray emission from hot gas and XRBs in the NGC 5846 galaxy
title_full X-ray emission from hot gas and XRBs in the NGC 5846 galaxy
title_fullStr X-ray emission from hot gas and XRBs in the NGC 5846 galaxy
title_full_unstemmed X-ray emission from hot gas and XRBs in the NGC 5846 galaxy
title_short X-ray emission from hot gas and XRBs in the NGC 5846 galaxy
title_sort x ray emission from hot gas and xrbs in the ngc 5846 galaxy
topic galaxies:general
galaxies:elliptical
galaxies:individual ngc 5846
x-rays:galactic medium
x-rays:binaries
url https://doi.org/10.1515/astro-2024-0008
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AT vagshettenilkanth xrayemissionfromhotgasandxrbsinthengc5846galaxy
AT patilmadhav xrayemissionfromhotgasandxrbsinthengc5846galaxy