The Circum-Galactic Medium of Massive Spirals. II. Probing the Nature of Hot Gaseous Halo around the Most Massive Isolated Spiral Galaxies
Year: 2017
Type: article
Abstract: We present the analysis of the XMM-Newton data of the Circum-Galactic Medium of MASsive Spirals (CGM-MASS) sample of six extremely massive spiral galaxies in the local universe. All the CGM-MASS galaxies have diffuse X-ray emission from hot gas detected above the background extending from the galactic center. This doubles the existing detection of such extended hot CGM around massive spiral galaxies. The radial soft X-ray intensity profile of hot gas can be fitted with a β-function, with the slope typically in the range of . This range, as well as those β values measured for other massive spiral galaxies, including the Milky Way (MW), are in general consistent with X-ray luminous elliptical galaxies of similar hot gas luminosity and temperature, and with those predicted from a hydrostatic-isothermal gaseous halo. Hot gas in such a massive spiral galaxy tends to have temperature comparable to its virial value, indicating the importance of gravitational heating. This is in contrast to lower mass galaxies, where hot gas temperature tends to be systematically higher than the virial one. The ratio of the radiative cooling to free fall timescales of hot gas is much larger than the critical value of ∼10 throughout the entire halos of all the CGM-MASS galaxies, indicating the inefficiency of gas cooling and precipitation in the CGM. The hot CGM in these massive spiral galaxies is thus most likely in a hydrostatic state, with the feedback material mixed with the CGM, instead of escaping out of the halo or falling back to the disk. We also homogenize and compare the halo X-ray luminosity measured for the CGM-MASS galaxies and other galaxy samples and discuss the “missing” galactic feedback detected in these massive spiral galaxies.
Authors: Jiang-Tao Li, Joel N. Bregman, Q. Daniel Wang, Robert A. Crain, Michael E. Anderson, Shangjia Zhang
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,499
Awards: GALAXY FORMATION MODELS PREDICT THAT MASSIVE SPIRAL GALAXIES PRODUCE EXTENSIVE HOT GASEOUS HALOS BY EXTERIOR ACCRETION SHOCKS AND GALACTIC FEEDBACK., SPIRAL AND ELLIPTICAL GALAXIES ARE MISSING MOST OF THEIR BARYONS, JUDGING BY THE STARS AND COLD DISK GAS. THEORY SUGGESTS THE MISSING BARYONS LIE IN
OpenAlex ID: W2765584426