The Circum-Galactic Medium of MASsive Spirals I: Overview and a Case Study of NGC 5908

Abstract

The Circum-Galactic Medium of MASsive Spirals (CGM-MASS) is a project studying the overall content, physical and chemical properties, and spatial distributions of the multi-phase circum-galactic medium (CGM) around a small sample of the most massive isolated spiral galaxies in the local Universe. We introduce the sample and present a detailed case study of the XMM-Newton observation of the hot gas halo of NGC5908. After data calibration, point source removal, and background analysis, we find that the diffuse soft X-ray emission of NGC5908 is significantly more extended than the stellar light in the vertical direction. The 0.5-1.25keV radial intensity profile tracing hot gas emission can be detected above the background out to about $2^{\prime }$, or $30\mathrm{kpc}$ from the nucleus. The unresolved soft X-ray emission can be characterized with a $\beta$-model with a slope of $\beta \approx 0.68$. The unresolved 0.5-2keV luminosity within $1^{\prime }$ is $6.8\times 10^{39}\mathrm{ergs}{\mathrm{s}}^{-1}$, but young stellar sources may contribute significantly to it. Assuming a metallicity of 0.2solar, an upper limit (without subtracting the very uncertain young stellar contribution) to the mass of hot gas within this radius is $2.3\times 10^9{\mathrm{M}}_{\odot }$. The cooling radius is $r_{\mathrm{cool}}\approx 25\mathrm{kpc}$ or $\approx 0.06r_{200}$, within which the hot gas could cool radiatively in less than 10Gyr, and the cooling of hot gas could significantly contribute in replenishing the gas consumed in star formation. The hot gas accounts for $\approx 1.9\%$ of the baryon detected within the cooling radius. By comparing NGC5908 to other galaxies, we find that its X-ray luminosity per stellar mass is consistent with lower-mass non-starburst field spiral galaxies. However, a large scatter in hot gas soft X-ray emissivity is indicated for spiral galaxies with $M_{\ast }\gtrsim 2\times 10^{11}{\mathrm{M}}_{\odot }$.

14 pages, 8 figures, 2 tables, accepted for publication in the The Astrophysical Journal

References in corpus (10)

• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• X-ray spectral properties of AGN in the Chandra Deep Field South
• The present-day star formation rate of the Milky-Way determined from Spitzer detected young stellar objects
• Kinematics of the Local Universe XIII. 21-cm line measurements of 452 galaxies with the Nançay radiotelescope, JHK Tully-Fisher relation and preliminary maps of the peculiar velocity field
• Constraining the Milky Way's Hot Gas Halo with OVII and OVII Emission Lines
• X-ray coronae in simulations of disc galaxy formation
• Universal X-ray emissivity of the stellar population in early-type galaxies: unresolved X-ray sources in NGC 3379
• Hot Gaseous Coronae around Spiral Galaxies: Probing the Illustris Simulation
• Spectral Modeling of the Charge-Exchange X-ray Emission from M82
• The multi-phase gaseous halos of star forming late-type galaxies - II. Statistical analysis of key parameters

Cited by in corpus (9)

• GASP XXIII: A jellyfish galaxy as an astrophysical laboratory of the baryonic cycle
• The Circum-Galactic Medium of MASsive Spirals II: Probing the Nature of Hot Gaseous Halo around the Most Massive Isolated Spiral Galaxies
• The eROSITA Final Equatorial Depth Survey (eFEDS): X-ray emission around star-forming and quiescent galaxies at $0.05<z<0.3$
• The hot circumgalactic medium in the eROSITA All-Sky Survey I. X-ray surface brightness profiles
• Scientific Objectives of the Hot Universe Baryon Surveyor (HUBS) Mission
• Molecular Gas of the Most Massive Spiral Galaxies I: a Case Study of NGC 5908
• The hot gas distribution, X-ray luminosity and baryon budget in the L-Galaxies semi-analytic model of galaxy formation
• Mock X-ray observations of hot gas with L-Galaxies semi-analytic models of galaxy formation
• CO-CHANGES II: spatially resolved IRAM 30M CO line observations of 23 nearby edge-on spiral galaxies