Related papers: X-ray Emission from Elliptical Galaxies
The recent {\em ASCA} results show that the iron abundance of the X-ray gas of elliptical galaxies is less than the solar abundance ($Z_{\sun}$). The observed low iron abundance is inconsistent with the predictions of the previous chemical…
We investigated the dynamical structure of 53 elliptical galaxies, based on the {\it Chandra} archival X-ray data. In X-ray luminous galaxies, a temperature increases with radius and a gas density is systematically higher at the optical…
We have derived the X-ray luminosities of a sample of galaxies in groups, making careful allowance for contaminating intragroup emission. The L_X:L_B and L_X:L_{FIR} relations of spiral galaxies in groups appear to be indistinguishable from…
The existence of hot, X-ray luminous gaseous coronae surrounding present day L* galaxies is a generic prediction of galaxy formation theory in the cold dark matter cosmogony. While extended X-ray emission has been known to exist around…
The Galactic plane is a strong hard x-ray emitter and the emission forms a narrow continuous ridge. The currently known hard x-ray sources are far too few to explain the ridge x-ray emission, and the fundamental question as to whether the…
We review recent progress in understanding the evolution of hot interstellar gas in the halos of elliptical galaxies. Non-homologous variations in the physical size of the hot gas account for the large variations of x-ray luminosity among…
To test the cooling flow model of early-type galaxies, we obtained a complete magnitude-limited sample of 34 early-type galaxies, observed with the PSPC and HRI on ROSAT. The X-ray to optical distribution of galaxies implies a lower…
I review results from {\sl Chandra} observations of nearby normal edge-on galaxies (Sd to Sa types). These galaxies have a broad range of star formation rate, but none of them is dominated by a nuclear starburst. The galaxies are all in…
I discuss the empirical properties of diffuse X-ray emitting gas in the halos of both nearby starburst galaxies and normal spiral galaxies, based on high resolution X-ray spectral imaging with the Chandra X-ray Observatory. Diffuse thermal…
Infrared emission has been detected from normal elliptical galaxies and from clusters of galaxies at 60um and 100um with the IRAS satellite. In both cases, the emission has the characteristics of cool dust with a temperature near 30K. For…
We present a study of the X-ray properties of a sample of six nearby late-type spiral galaxies based on XMM-Newton observations. Since our primary focus is on the linkage between X-ray emission and star formation in extended, extranuclear…
Optical parameters of elliptical galaxies are tightly correlated, but their x-ray parameters vary widely. The x-ray luminosity L_x ranges over more than an order of magnitude for ellipticals having similar optical luminosity L_B. The source…
ROSAT observations indicate that approximately half of all nearby groups of galaxies contain spatially extended X-ray emission. The radial extent of the X-ray emission is typically 50-500 kpc or approximately 10-50% of the virial radius of…
We present an X-ray analysis of 54 normal elliptical galaxies in the Chandra archive and isolate their hot gas component from the contaminating point source emission, allowing us to conduct, for the first time, a morphological analysis on…
We present the results of a new set of hydrodynamical simulations of hot gas flows in model elliptical galaxies with the following characteristics: the spatial luminosity distribution approaches a power law form at small radii, in…
Hot gas dominates the emission in X-ray luminous early-type galaxies, but in relatively X-ray faint systems, integrated X-ray emission from discrete stellar-like sources is thought to be considerable, although the amount of the contribution…
X-ray emitting gaseous halos, such as that in elliptical galaxies like NGC 4472, cannot have been produced solely from gas expelled from galactic stars. In traditional models for the evolution of hot interstellar gas (cooling flows) in…
Long slit spectroscopic data for 7 early-type galaxies with X-ray emission have been analyzed to derive velocity dispersion and radial velocity profiles. Major axis rotation curves out to $R\sim R_e$ are presented. Adding these new data to…
The star formation (SF) can be regarded as an engine powering the light emission of spiral galaxies at several wavelengths. SF activity also plays a significant role in the evolution of galaxies. In this thesis we focus on the X-ray…
The X-ray emission from normal elliptical galaxies has two major components: soft emission from diffuse gas and harder emission from populations of accreting (low-mass) stellar X-ray binaries (LMXB). If LMXB populations are tied to the…