scholarly journals X-Ray Observations of Elliptical Galaxies by ASCA Satellite

1996 ◽  
Vol 171 ◽  
pp. 412-412
Author(s):  
K. Matsushita ◽  
K. Makishima
Keyword(s):  
Low Temperature ◽  
Mass Loss ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
Plasma Emission ◽  
X Ray ◽  
Theoretical Predictions ◽  
Long Time ◽  
Temperature Component ◽  
Hubble Time

Using ASCA, we have confirmed that the ISM of X-ray bright elliptical galaxies are surprisingly metal poor, as compared to the theoretical predictions. In fact the exact values of the derived metallicity depend considerably on the plasma emission codes. However, the overall metallicity cannot be larger than ∼ 1 solar. For low LX/LB galaxies, all the available plasma codes suggest abundances less than half a solar. The ASCA spectra may be compatible with somewhat higher metallicity if we assume there is an additional low-temperature component (e.g. kTe ∼ 0.3 keV). However, the derived abundance can not be over 1 solar. In particular, the Si abundance turns out to be < 1.5 solar, confirming the metal-poor nature of the ISM. These ASCA results are in severe contradiction with most of the SN Ia rate, particularly that of Tammann (1982). Considering further that a fairly long time (109–10yr) is needed for the stellar mass loss to accumulates into the ISM, it is suggested that the SN Ia rate has remained quite low throughout Hubble time.

scholarly journals X-Rays from Elliptical Galaxies

1987 ◽  
Vol 127 ◽  
pp. 155-165
Author(s):  
A.C. Fabian ◽  
P.A. Thomas
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Mass Loss ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
X Rays ◽  
Early Type ◽  
X Ray ◽  
Isolated Galaxies

X-ray observations have shown that early-type galaxies contain a hot interstellar medium. This implies that the galaxies have a) a low supernova rate; b) high total gravitational binding masses and c) continuous star formation. Much of the gas in isolated galaxies is probably due to stellar mass-loss. The details of its behaviour are complex.

scholarly journals Massive star mass-loss revealed by X-ray observations of young supernovae

2018 ◽  
Vol 14 (S346) ◽  
pp. 83-87
Author(s):  
Vikram V. Dwarkadas
Keyword(s):  
Mass Loss ◽  
Massive Stars ◽  
Ambient Medium ◽  
Mass Loss Rate ◽  
Stellar Mass ◽  
X Rays ◽  
X Ray ◽  
The Common ◽  
Almost All ◽  
Loss Rates

AbstractMassive stars lose a considerable amount of mass during their lifetime. When the star explodes as a supernova (SN), the resulting shock wave expands in the medium created by the stellar mass-loss. Thermal X-ray emission from the SN depends on the square of the density of the ambient medium, which in turn depends on the mass-loss rate (and velocity) of the progenitor wind. The emission can therefore be used to probe the stellar mass-loss in the decades or centuries before the star’s death.We have aggregated together data available in the literature, or analysed by us, to compute the X-ray lightcurves of almost all young supernovae detectable in X-rays. We use this database to explore the mass-loss rates of massive stars that collapse to form supernovae. Mass-loss rates are lowest for the common Type IIP supernovae, but increase by several orders of magnitude for the highest luminosity X-ray SNe.

X-ray induced stellar mass loss near active galactic nuclei

1988 ◽  
Vol 331 ◽  
pp. 197 ◽  
Author(s):  
G. Mark Voit ◽  
J. Michael Shull
Keyword(s):  
Mass Loss ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
X Ray

scholarly journals Evolution of the Coronae in Early-Type Galaxies

1990 ◽  
Vol 115 ◽  
pp. 240-244
Author(s):  
L.P. David ◽  
W. Forman ◽  
C. Jones
Keyword(s):  
Mass Loss ◽  
Numerical Simulations ◽  
Elliptical Galaxies ◽  
Compact Groups ◽  
Type I ◽  
Dark Halo ◽  
Early Type ◽  
X Ray ◽  
Galactic Winds ◽  
The Galaxy

AbstractWe present numerical simulations of the gaseous coronae in elliptical galaxies. These models consist of a modified King profile for the luminous portion of the galaxy and an isothermal dark halo. We include evolving stellar mass loss from planetary nebulae, and type I and II supernovae. Our models show that elliptical galaxies are likely to produce strong galactic winds at early times with x-ray luminosities of 1042 — 1044 ergs s-1 and temperatures of 10 keV. Galaxies can lose approximately 10-30% of their initial luminous mass in the wind which has an oxygen-to-iron ratio twice the solar value. Since elliptical galaxies are a principle component of rich clusters and compact groups this early wind phase affects the metallicity and temperature of the intracluster medium.

scholarly journals Suzaku observation of the metallicity in the interstellar medium of NGC 1316

2009 ◽  
Vol 5 (H15) ◽  
pp. 286-286
Author(s):  
S. Konami ◽  
K. Matsushita ◽  
K. Sato ◽  
R. Nagino ◽  
N. Isobe ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Mass Loss ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
Metal Enrichment ◽  
Abundance Pattern ◽  
Type Ia ◽  
History Of ◽  
Metal Abundances ◽  
Formation And Evolution

Metal abundances of the hot X-ray emitting interstellar medium (ISM) include important information to understand the history of star formation and evolution of galaxies. The metals are mainly synthesized by Type Ia (SNe Ia) and stellar mass loss in elliptical galaxies. The productions of stellar mass loss reflect stellar metallicity. SNe Ia mainly product Fe. Therefore, the abundance pattern of ISM can play key role to investigate the metal enrichment history.

scholarly journals X-rays from colliding winds in massive binaries

2016 ◽  
Vol 12 (S329) ◽  
pp. 359-360
Author(s):  
Yaël Nazé ◽  
Gregor Rauw
Keyword(s):  
High Resolution ◽  
Mass Loss ◽  
Strong Shock ◽  
Stellar Mass ◽  
Stellar Winds ◽  
X Rays ◽  
Current Generation ◽  
X Ray ◽  
Colliding Winds

AbstractIn a massive binary, the strong shock between the stellar winds may lead to the generation of bright X-ray emission. While this phenomenon was detected decades ago, the detailed study of this emission was only made possible by the current generation of X-ray observatories. Through dedicated monitoring and observations at high resolution, unprecedented information was revealed, putting strong constraints on the amount and structure of stellar mass-loss.

scholarly journals The Hydrodynamical Evolution of Gas in Young Elliptical Galaxies

1987 ◽  
Vol 127 ◽  
pp. 437-438
Author(s):  
R. Kunze ◽  
H.H. Loose ◽  
H.W. Yorke
Keyword(s):  
Mass Loss ◽  
Thermal Instability ◽  
Elliptical Galaxy ◽  
Forthcoming Paper ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
Early Epoch ◽  
The Galaxy ◽  
Bulk Energy ◽  
Gas Cloud

We calculate the partial inflow of gas fuelled by stellar mass loss at an early epoch (109yr after the birth of the galaxy) during the evolution of an elliptical galaxy assuming a modified King model stellar distribution. The influence of the partial thermalization of stellar mass lost on the amount of gas which can be stored in the nucleus of a typical elliptical during the time of partial inflow is investigated. Masses up to 105M⊙ of cool (≤ 104K) material can be stored in the nucleus of the galaxy before the fast dissipation of the “kinetic bulk energy” of the nuclear gas cloud leads to “thermal” instability and subsequent collapse. A supermassive star can form. A detailed discussion of the model and the results is subject of a forthcoming paper (Kunze et al., 1986).

The Long-Time Low-Temperature Degradation (“LTD”) Kinetics in 3Y-TZP Bioceramics

2012 ◽  
Vol 529-530 ◽  
pp. 589-594
Author(s):  
Klaus G. Nickel ◽  
Melanie Keuper ◽  
Christoph Berthold
Keyword(s):  
Low Temperature ◽  
Time Use ◽  
Linear Growth ◽  
Elevated Temperatures ◽  
Slow Crack Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crack Interactions ◽  
Long Time ◽  
Long Lifetime

This work follows a study on hydrothermal aged 3Y-TZP bioceramics, which showed that the surface X-ray diffraction data from moisture exposed samples give distorted results, reflecting a simple linear growth of a partially transformed layer from the surface into the interior. There is no indication for a leveling off or retardation of this growth at elevated temperatures (134°C) and here we present evidence that this is probably true at body temperatures as well. However, the rate constants at body temperature for the studied material are low and indicate a long lifetime. It should be noted that this statement is specific and other materials with minor changes to chemistry or microstructure may behave much better or much worse under those conditions. Furthermore slow crack growth and crack interactions are not yet investigated and may necessitate a minimum of low-temperature degradation susceptibility to ensure reliable long-time use.

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