The Evolution of Isotope Ratios in the Milky Way Galaxy
... metals are produced. This assumption may not be valid but does not affect the average chemical evolution of galaxies. Super AGB stars — The fate of stars with initial masses between about 8 − 10M⊙ is uncertain. The upper limit of AGB stars, Mu,1 , is defined as the minimum mass for carbon ignition, ...
... metals are produced. This assumption may not be valid but does not affect the average chemical evolution of galaxies. Super AGB stars — The fate of stars with initial masses between about 8 − 10M⊙ is uncertain. The upper limit of AGB stars, Mu,1 , is defined as the minimum mass for carbon ignition, ...
ASTRONOMY AND ASTROPHYSICS Elemental abundances of
... to metallicity effects. For example, the Lyα/ CIV1549 ratio is nearly independent to heavy element abundances (Hamann & Ferland 1999). However, there are several emission line ratios which are sensitive to relative abundance ratios and these can be used to put constraints on both the metallicity and ...
... to metallicity effects. For example, the Lyα/ CIV1549 ratio is nearly independent to heavy element abundances (Hamann & Ferland 1999). However, there are several emission line ratios which are sensitive to relative abundance ratios and these can be used to put constraints on both the metallicity and ...
A non-LTE analysis of the hot subdwarf O star BD+28°4211
... properly, with the higher lines in the series needing models at higher temperatures. For example, for BD+28◦ 4211, Hα was best reproduced at T eff 50 000 K and H at around 85 000 K (Napiwotzki 1993). In a situation like this, it is rather difficult to determine the temperature of the star without an ...
... properly, with the higher lines in the series needing models at higher temperatures. For example, for BD+28◦ 4211, Hα was best reproduced at T eff 50 000 K and H at around 85 000 K (Napiwotzki 1993). In a situation like this, it is rather difficult to determine the temperature of the star without an ...
HenryWeller_QCDTownMeeting
... additional resources are needed to assure that 160 MeV is reached (150 nm mirrors) with full flux in a timely manner. Funding presently limits operations to 1000 hrs/yr. In order to execute this program we would like to increase this to 3000 hours per year. This requires significant additional $uppo ...
... additional resources are needed to assure that 160 MeV is reached (150 nm mirrors) with full flux in a timely manner. Funding presently limits operations to 1000 hrs/yr. In order to execute this program we would like to increase this to 3000 hours per year. This requires significant additional $uppo ...
Accreting Neutron Stars: Strong Gravity and Type I Bursts
... et al., 2007) is that neutron stars are compact objects of mass M ∼ 1.4 M⊙ and radius R ∼ 10 km, the high M/R ratio being what makes them compact. Such high compactness also makes them general relativistic objects. Spacetime is highly curved around them and effects such as gravitational redshift, be ...
... et al., 2007) is that neutron stars are compact objects of mass M ∼ 1.4 M⊙ and radius R ∼ 10 km, the high M/R ratio being what makes them compact. Such high compactness also makes them general relativistic objects. Spacetime is highly curved around them and effects such as gravitational redshift, be ...
Type Ia Supernovae
... group of supernovae, the thermonuclear explosions of degenerate carbon and oxygen rich material and lacking hydrogen - called Type Ia supernovae (SNe Ia). White dwarf stars are formed at the end of a typical star’s life when nuclear burning ceases in the core, the outer envelope is ejected, with the ...
... group of supernovae, the thermonuclear explosions of degenerate carbon and oxygen rich material and lacking hydrogen - called Type Ia supernovae (SNe Ia). White dwarf stars are formed at the end of a typical star’s life when nuclear burning ceases in the core, the outer envelope is ejected, with the ...
Introduction to Solid State NMR
... In order for the MAS method to be successful, spinning has to occur at a rate equal to or greater than the dipolar linewidth (which can be many kHz wide). On older NMR probe designs, it was not possible to spin with any stability over 1 kHz! ...
... In order for the MAS method to be successful, spinning has to occur at a rate equal to or greater than the dipolar linewidth (which can be many kHz wide). On older NMR probe designs, it was not possible to spin with any stability over 1 kHz! ...
Solid State NMR
... In order for the MAS method to be successful, spinning has to occur at a rate equal to or greater than the dipolar linewidth (which can be many kHz wide). On older NMR probe designs, it was not possible to spin with any stability over 1 kHz! ...
... In order for the MAS method to be successful, spinning has to occur at a rate equal to or greater than the dipolar linewidth (which can be many kHz wide). On older NMR probe designs, it was not possible to spin with any stability over 1 kHz! ...
exploring anticorrelations and light element variations
... inhomogeneities are ubiquitous in Galactic GCs, though they do not appear to occur in other star formation environments. However, the extent of the inhomogeneity varies from cluster to cluster, and appears to correlate strongly with the presentday total mass of the GCs, and also with metallicity. Th ...
... inhomogeneities are ubiquitous in Galactic GCs, though they do not appear to occur in other star formation environments. However, the extent of the inhomogeneity varies from cluster to cluster, and appears to correlate strongly with the presentday total mass of the GCs, and also with metallicity. Th ...
The Milky Way Laboratory
... Next Steps: The Skeleton of the Milky Way • Identify more Bones of the Milky Way. Combine with other tracers (e.g. CO, HI, dense gas) to develop a model of Galactic structure • Measure physical properties and kinematics of Bones – compare directly with simulations. Develop improved Galactic-scale s ...
... Next Steps: The Skeleton of the Milky Way • Identify more Bones of the Milky Way. Combine with other tracers (e.g. CO, HI, dense gas) to develop a model of Galactic structure • Measure physical properties and kinematics of Bones – compare directly with simulations. Develop improved Galactic-scale s ...
Krypton in presolar mainstream SiC grains from AGB stars
... (4.737±0.021 mb, 30 keV). Its production by the s−process depends on the 85 Kr neutron channel. 85 Kr is an unstable isotope, characterised by a ground state, 85 Krg (t1/2 = 10.76 yr), and an isomeric state, 85 Krm (t1/2 = 4.48 h). About 50 % of the neutron capture of 84 Kr feeds 85 Krm (Bao et al. ...
... (4.737±0.021 mb, 30 keV). Its production by the s−process depends on the 85 Kr neutron channel. 85 Kr is an unstable isotope, characterised by a ground state, 85 Krg (t1/2 = 10.76 yr), and an isomeric state, 85 Krm (t1/2 = 4.48 h). About 50 % of the neutron capture of 84 Kr feeds 85 Krm (Bao et al. ...
L95 IRON-RICH EJECTA IN THE SUPERNOVA
... spectra near optical maximum, the occurrence in older stellar populations, and the relatively large amount of 56Ni produced) have led to the current framework involving carbon deflagration/detonation in a white dwarf driven to the Chandrasekhar limit by accretion. The most likely progenitor system ( ...
... spectra near optical maximum, the occurrence in older stellar populations, and the relatively large amount of 56Ni produced) have led to the current framework involving carbon deflagration/detonation in a white dwarf driven to the Chandrasekhar limit by accretion. The most likely progenitor system ( ...
A Disintegrating Minor Planet Transiting a White Dwarf
... 1/4 and 1/2 of white dwarfs have elements heavier than helium in their atmospheres1,2, even though these elements should rapidly settle into the stellar interiors unless they are occasionally replenished 3–5 . The abundance ratios of heavy elements in white dwarf atmospheres are similar to rocky bod ...
... 1/4 and 1/2 of white dwarfs have elements heavier than helium in their atmospheres1,2, even though these elements should rapidly settle into the stellar interiors unless they are occasionally replenished 3–5 . The abundance ratios of heavy elements in white dwarf atmospheres are similar to rocky bod ...
ASTRONOMY AND ASTROPHYSICS The 10–200µm spectral
... the steep ultraviolet continuum, fλ ∝ λ1.7 , may be produced by a very dusty starburst. This was later confirmed by Bonatto et al. (1998), who reproduced the ultraviolet continuum of a sample of nearby spiral galaxies by stellar population synthesis and concluded that in the case of NGC 7582 the UV ...
... the steep ultraviolet continuum, fλ ∝ λ1.7 , may be produced by a very dusty starburst. This was later confirmed by Bonatto et al. (1998), who reproduced the ultraviolet continuum of a sample of nearby spiral galaxies by stellar population synthesis and concluded that in the case of NGC 7582 the UV ...
Gamow-Teller response in deformed even and odd neutron
... solutions, in general deformed, for which minima are obtained in the energy curves. Since decays connecting different shapes are disfavored, similar shapes are assumed for the ground state of the parent nucleus and for all populated states in the daughter nucleus. The validity of this assumption was ...
... solutions, in general deformed, for which minima are obtained in the energy curves. Since decays connecting different shapes are disfavored, similar shapes are assumed for the ground state of the parent nucleus and for all populated states in the daughter nucleus. The validity of this assumption was ...
Chemical Composition of Selected Metal Poor Stars
... Planetary Nebulae (central hot star ionizing the dust envelope ejected during the AGB phase). ...
... Planetary Nebulae (central hot star ionizing the dust envelope ejected during the AGB phase). ...
Gamma-Ray Bursts
... star explodes in a supernova explosion. The core collapses into a neutron star, and the rest of the star explodes in a supernova explosion. The core collapses into a white dwarf, and the rest of the star explodes to form a planetary nebula. The core collapses into a neutron star, and the rest of the ...
... star explodes in a supernova explosion. The core collapses into a neutron star, and the rest of the star explodes in a supernova explosion. The core collapses into a white dwarf, and the rest of the star explodes to form a planetary nebula. The core collapses into a neutron star, and the rest of the ...
On the interpretation of stellar disc observations in terms of diameters
... do not show up in a realistic stellar atmosphere, but steep intensity declines are common features both at the edge of very compact or slightly extended and at inner disc positions of significantly extended atmospheric configurations. Since, even in a very compact configuration, rays along the line ...
... do not show up in a realistic stellar atmosphere, but steep intensity declines are common features both at the edge of very compact or slightly extended and at inner disc positions of significantly extended atmospheric configurations. Since, even in a very compact configuration, rays along the line ...
Chemical composition of cosmic dust in the solar vicinity
... F&G stars: + differential abundances relative to Sun + increased number statistics - difficult age determination - non-LTE & 3D-corrections (convection) not considered early B stars: + short-lived: formed out of presen-day ISM + simple atmospheric physics - non-LTE dominated Sofia & Meyer (2001): re ...
... F&G stars: + differential abundances relative to Sun + increased number statistics - difficult age determination - non-LTE & 3D-corrections (convection) not considered early B stars: + short-lived: formed out of presen-day ISM + simple atmospheric physics - non-LTE dominated Sofia & Meyer (2001): re ...
P-nuclei
p-Nuclei (p stands for proton-rich) are certain proton-rich, naturally occurring isotopes of some elements between selenium and mercury which cannot be produced in either s- or r-process.