ISM Of Elliptical Galaxies Research Articles

A multi-instrument comparison of the hot ISM in elliptical galaxies

AbstractConsistent metallicities are now obtained in X-ray bright galaxies, using the Chandra ACIS and XMM PN, MOS and RGS detectors. With two temperature models, the Fe metallicity of the gas is typically solar, similar to Mg, Si, and S, but the O abundance is about half solar. These values are in conflict with models, which predict a metallicity 3-5 times higher and a Fe to O ratio near unity. This suggests that a significant fraction of metals are not becoming mixed into the hot galactic atmosphere.

JD8 - Hot Interstellar Matter in Elliptical Galaxies

The physical properties of the hot interstellar matter in elliptical galaxies are directly related with the formation and evolution of elliptical galaxies via star formation episodes, environmental effects such as stripping, infall, and mergers, and growth of super-massive black holes. The recent successful Chandra and XMM-Newton X-ray space missions have provided a large amount of high spatial/spectral resolution observational data on the hot ISM in elliptical galaxies. At the same time, theoretical studies with numerical simulations and analytical modeling of the dynamical and chemical evolution of elliptical galaxies have made a significant progress and start to predict various observable quantities.

Hyperfine structure radio lines from hot ISM in elliptical galaxies

AbstractHyperfine structure (HFS) line of 14N VII ion with rest frequency of ν = 53.04 GHz should be detectable from the interstellar medium in some of the densest and coolest cores of elliptical galaxies at redshifts exceeding 0.15 or so.

The hot ISM of early-type galaxies

AbstractThis talks reviews the history of the discovery of the hot ISM in elliptical galaxies, and the ensuing debate on the suitability of X-ray observations of these galaxies for mass measurements. How much of the X-ray emission is truly from a hot ISM, and is this ISM in hydrostatic equilibrium? While the debate went on, a deeper understanding on the evolution of the halos was generated. High resolution Chandra observations are providing an answer.

The Cool ISM in Elliptical Galaxies. I. A Survey of Molecular Gas

We present preliminary results from a survey of CO emission from members of a volume-limited sample of noncluster elliptical galaxies. Our intent is to compare the gas properties of these ellipticals to a sample of lenticulars selected using similar criteria. The data, although still sparse, suggest that the cool gas in ellipticals shows the same puzzling upper mass cutoff found in the lenticular galaxies. We find, however, significantly lower detection rates and possibly much lower H2/Himass ratios in the ellipticals. The detection rate is higher among the lower mass galaxies, ashasbeenfoundpreviously.Thisseemspuzzlinggiventhat thedeeperpotentialwells of thelargergalaxies oughtto make gas retention easier, but perhaps that effect is overwhelmed by feedback from the central supermassive black hole. As we have observed � 40% of our full sample, the conclusions are necessarily tentative at this time. Subject headingg galaxies: elliptical and lenticular, cD — galaxies: evolution — galaxies: ISM

Evolution of Multiphase Hot Interstellar Medium in Elliptical Galaxies

Theoretical arguments indicate that the ISM is inhomogeneous; Mathews estimated that the ~ 1M⊙ of metal ejected by each supernova event into the ISM is trapped locally within the hot bubbles. Since in elliptical galaxies, there is no overlapping of expanding supernova remnants after galactic wind period, it is expected that this inhomogeneity persists for a long time. The observations also suggests that the ISM of elliptical galaxies is inhomogeneous. Based on these arguments, we studied the evolution of the multiphase (inhomogeneous) ISM.