Accretion Processes of Binaries of White Dwarfs
... 1. Mass losing giant may shed a large amount of mass in the form of the slow stellar wind 2. SPH simulations show that steady accretion disk can be formed via gravitational capture of slow stellar wind ...
... 1. Mass losing giant may shed a large amount of mass in the form of the slow stellar wind 2. SPH simulations show that steady accretion disk can be formed via gravitational capture of slow stellar wind ...
Introducing the fission–fusion reaction process: using a
... density functional calculations have to be fitted to experimental data of heavy nuclei, in order to enable reliable predictions for other nuclei [28]. If we improve our experimental understanding of this final bottleneck to the actinides at N = 126, many new visions open up: (i) For many mass formul ...
... density functional calculations have to be fitted to experimental data of heavy nuclei, in order to enable reliable predictions for other nuclei [28]. If we improve our experimental understanding of this final bottleneck to the actinides at N = 126, many new visions open up: (i) For many mass formul ...
Spectral Matching for Elemental Abundances of Evolved Stars of Globular Clusters
... used to estimate the oxygen abundance of the stars, leading to a determination of whether a particular star was oxygen-rich or oxygen-poor. From this a catalogue of abundances of iron, carbon and barium of 848 giant branch stars were determined, of which 557 also had well-defined nitrogen abundances ...
... used to estimate the oxygen abundance of the stars, leading to a determination of whether a particular star was oxygen-rich or oxygen-poor. From this a catalogue of abundances of iron, carbon and barium of 848 giant branch stars were determined, of which 557 also had well-defined nitrogen abundances ...
Chapter 16 Option E: ASTROPHYSICS
... In Topic 7.3.8 we discussed the topic of nuclear fusion, the process in which two lighter elements such as hydrogen can combine to form a heavier element such as helium and in the process liberate energy. We now know that this conversion of hydrogen to helium is the main source of energy for the sta ...
... In Topic 7.3.8 we discussed the topic of nuclear fusion, the process in which two lighter elements such as hydrogen can combine to form a heavier element such as helium and in the process liberate energy. We now know that this conversion of hydrogen to helium is the main source of energy for the sta ...
4. Stars and resolved stellar populations
... III]/Hβ ratio is a crucial indicator of fast shocks with speed above 100 km/s, while [S II] 6716/6731, [NII]/[O I], and [SII]/[O I] provide direct estimates of, respectively, the jet electronic density, ionization fraction and temperature, with much less dependence on the heating process than ratios ...
... III]/Hβ ratio is a crucial indicator of fast shocks with speed above 100 km/s, while [S II] 6716/6731, [NII]/[O I], and [SII]/[O I] provide direct estimates of, respectively, the jet electronic density, ionization fraction and temperature, with much less dependence on the heating process than ratios ...
Disk
... outflow detection rate = 40-90% in massive YSOs (luminous IRAS sources, UC HIIs, H2O masers,…) (Osterloh et al., Beuther et al., Zhang et al., …) disks should be widespread! ...
... outflow detection rate = 40-90% in massive YSOs (luminous IRAS sources, UC HIIs, H2O masers,…) (Osterloh et al., Beuther et al., Zhang et al., …) disks should be widespread! ...
Mass segregation in star clusters is not energy equipartition
... and find similar results; the most massive stars sink to the centre more rapidly than the average star and form an unstable higher-order multiple system, which decays by ejecting one or more massive stars. This suggests that mass-loss via stellar evolution is not a strong influence on our results. I ...
... and find similar results; the most massive stars sink to the centre more rapidly than the average star and form an unstable higher-order multiple system, which decays by ejecting one or more massive stars. This suggests that mass-loss via stellar evolution is not a strong influence on our results. I ...
LSS-GAC – A LAMOST Spectroscopic Survey of the Galactic Anti
... observation (e.g. the positioning of field center, the holes in focal plane produced by the guiding CCDs and the central Shack Hartmann Sensor, allocations of fibers, spectral S/N, etc) have been properly taken into account. Meanwhile in order to increase the discovery space, rare objects of extreme ...
... observation (e.g. the positioning of field center, the holes in focal plane produced by the guiding CCDs and the central Shack Hartmann Sensor, allocations of fibers, spectral S/N, etc) have been properly taken into account. Meanwhile in order to increase the discovery space, rare objects of extreme ...
LSS-GAC – A LAMOST Spectroscopic Survey of the
... Galaxies are building blocks of the universe. Understanding how galaxies assemble and acquire their characteristic structure and properties (the “grand designs”) is one of the most challenging problems of astrophysics. In the current ΛCDM paradigm, all cosmic structures including galaxies build up h ...
... Galaxies are building blocks of the universe. Understanding how galaxies assemble and acquire their characteristic structure and properties (the “grand designs”) is one of the most challenging problems of astrophysics. In the current ΛCDM paradigm, all cosmic structures including galaxies build up h ...
Delta isobars in neutron stars
... is converted within a few milliseconds. Moreover, since the energy released in such a process is of the order of 1052 erg, it is clear that a similar event would provide very strong neutrino and electromagnetic signals, possibly connected with supernovae and gamma-ray-bursts [40, 42, 53–55]. An inte ...
... is converted within a few milliseconds. Moreover, since the energy released in such a process is of the order of 1052 erg, it is clear that a similar event would provide very strong neutrino and electromagnetic signals, possibly connected with supernovae and gamma-ray-bursts [40, 42, 53–55]. An inte ...
Red Supergiants, Luminous Blue Variables and Wolf
... collapse supernova types (II, Ib, Ic) at various metallicities. In the following we discuss the importance of mass loss and rotation in the context of these questions and we propose some directions of research for future investigations. Very interesting and informative reviews on these topics have r ...
... collapse supernova types (II, Ib, Ic) at various metallicities. In the following we discuss the importance of mass loss and rotation in the context of these questions and we propose some directions of research for future investigations. Very interesting and informative reviews on these topics have r ...
Influence of Opacity on the Pulsational Stability Of Massive Stars
... the critically stable nondimensional mass of hydrogen-burning stars, (M 1M 0)1-'2, can range from 27 to 94, depending on the chemical composition. For likely chemical compositions of extreme Population I, the actual critical mass is probably 80-120 M 0' For homogeneous helium-burning stars, the crit ...
... the critically stable nondimensional mass of hydrogen-burning stars, (M 1M 0)1-'2, can range from 27 to 94, depending on the chemical composition. For likely chemical compositions of extreme Population I, the actual critical mass is probably 80-120 M 0' For homogeneous helium-burning stars, the crit ...
The Correlation of Lithium and Beryllium in F and G
... stars as the convection zone deepens and more Li is depleted relative to Be. ...
... stars as the convection zone deepens and more Li is depleted relative to Be. ...
Stars, Galaxies, and the Universe
... the two universe ofstars singleare as stars, all called ofstar space double systems, and starsclusters, star everything or binary in it. dust, stars. and gas bound together by gravity. An eclipsing Scientific notation binaryuses is a star powers system of ten in to which writeone very star cannot la ...
... the two universe ofstars singleare as stars, all called ofstar space double systems, and starsclusters, star everything or binary in it. dust, stars. and gas bound together by gravity. An eclipsing Scientific notation binaryuses is a star powers system of ten in to which writeone very star cannot la ...
Carnegie Observatories Astrophysics Series, Vol. 4:
... that are “missing” from the gas phase are located in solid particles – interstellar dust grains. The existence of this solid phase complicates efforts to determine elemental abundances, due to the difficult-to-determine abundance in grains. The concentration of certain elements in dust grains also c ...
... that are “missing” from the gas phase are located in solid particles – interstellar dust grains. The existence of this solid phase complicates efforts to determine elemental abundances, due to the difficult-to-determine abundance in grains. The concentration of certain elements in dust grains also c ...
Metallicity maps
... Ram-pressure stripping can produce considerably more metals than galactic winds (depending on cluster mass and other cluster properties) Schindler et al. 2005, Kapferer et al. 2007, 2009 ...
... Ram-pressure stripping can produce considerably more metals than galactic winds (depending on cluster mass and other cluster properties) Schindler et al. 2005, Kapferer et al. 2007, 2009 ...
Cosmology - Stockton University
... with less mass show up as lighter areas while regions with more mass are darker. The grayed-out areas are where light from our own galaxy was too bright, blocking Planck's ability to map the more distant matter. Normal matter, which is made up of atoms, is only a small percent of the total mass in o ...
... with less mass show up as lighter areas while regions with more mass are darker. The grayed-out areas are where light from our own galaxy was too bright, blocking Planck's ability to map the more distant matter. Normal matter, which is made up of atoms, is only a small percent of the total mass in o ...
On the dynamics of proto-neutron star winds and r
... the outflow abruptly. They found that the position of the reverse shock is strongly dependent on the evolution phase, progenitor structure, and explosion energy of the supernova. Motivated by these studies, interest has recently turned to a closer exploration of the relevance of the late-time wind d ...
... the outflow abruptly. They found that the position of the reverse shock is strongly dependent on the evolution phase, progenitor structure, and explosion energy of the supernova. Motivated by these studies, interest has recently turned to a closer exploration of the relevance of the late-time wind d ...
The Stellar Population And Origin Of The Mysterious K.V. Getman
... made 30 years ago by Williams et al. (1977) who suggested that a large expanding highlatitude interstellar shell could have traversed CG12 7-19 Myr ago. Produced by one or more supernova explosions from a still-unidentified association, the encounter would have drawn out the 10 pc-long tail and trig ...
... made 30 years ago by Williams et al. (1977) who suggested that a large expanding highlatitude interstellar shell could have traversed CG12 7-19 Myr ago. Produced by one or more supernova explosions from a still-unidentified association, the encounter would have drawn out the 10 pc-long tail and trig ...
The Eight Parts of Speech:
... group of stars, and interstellar space is the deep space between the stars. ...
... group of stars, and interstellar space is the deep space between the stars. ...
CH30 p798
... iron, Fe. The most tightly bound nucleus is 56 26Fe; thus, nuclei become more stable as their mass numbers approach that of iron. Nuclei whose mass numbers are larger than that of iron are less strongly bound, and are therefore less stable. A nuclear reaction will occur naturally if energy is releas ...
... iron, Fe. The most tightly bound nucleus is 56 26Fe; thus, nuclei become more stable as their mass numbers approach that of iron. Nuclei whose mass numbers are larger than that of iron are less strongly bound, and are therefore less stable. A nuclear reaction will occur naturally if energy is releas ...
(Relative) Distances from the HST Snapshot Database
... Canonical models predict that the HeII convective region approaches the stellar surface in the ZAHB structures at T=23.000. In addition, mass loss, which is a competing process to diffusion increases with effective temperature. As a result, radiative levitation is less and less effective in the temp ...
... Canonical models predict that the HeII convective region approaches the stellar surface in the ZAHB structures at T=23.000. In addition, mass loss, which is a competing process to diffusion increases with effective temperature. As a result, radiative levitation is less and less effective in the temp ...
NUCLEI of ATOMS Vladislav Konovalov Abstract
... place under operating same of gravidynamic forces at unidirectional motion a neutrino of approaching nucleons, inside which they moves counterly and are attracted. "These experiments have shown also, that on spacing intervals 0.3 – 0.5 fermi between nucleons arise a very large repulsive force (for ...
... place under operating same of gravidynamic forces at unidirectional motion a neutrino of approaching nucleons, inside which they moves counterly and are attracted. "These experiments have shown also, that on spacing intervals 0.3 – 0.5 fermi between nucleons arise a very large repulsive force (for ...
White Dwarf Stars
... around to see such an alien sky is another question: All life on Earth would have been obliterated when the Sun entered its red-giant stage a billion years earlier. The white dwarf will endure for many billions of years afterward as a small monument to our solar system. Our Sun may be billions of ye ...
... around to see such an alien sky is another question: All life on Earth would have been obliterated when the Sun entered its red-giant stage a billion years earlier. The white dwarf will endure for many billions of years afterward as a small monument to our solar system. Our Sun may be billions of ye ...
IEEE 2 Column Format
... segregation within the cluster. The relaxation time of the cluster has seemed to be much higher than its age due to the restricted boundary limit of red and blue sequences of photometric criteria, the present results are imprinted for denying the possibility of the dynamic relaxation of the cluster. ...
... segregation within the cluster. The relaxation time of the cluster has seemed to be much higher than its age due to the restricted boundary limit of red and blue sequences of photometric criteria, the present results are imprinted for denying the possibility of the dynamic relaxation of the cluster. ...
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen and helium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos.With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis, a process that continues today. Some of these elements, particularly those lighter than iron, continue to be delivered to the interstellar medium when low mass stars eject their outer envelope before they collapse to form white dwarfs. The remains of their ejected mass form the planetary nebulae observable throughout our galaxy.Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28). Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the R process) in the period of a few seconds during the explosion. The elements formed in supernovas include the heaviest elements known, such as the long-lived elements uranium and thorium.Cosmic ray spallation, caused when cosmic rays impact the interstellar medium and fragment larger atomic species, is a significant source of the lighter nuclei, particularly 3He, 9Be and 10,11B, that are not created by stellar nucleosynthesis.In addition to the fusion processes responsible for the growing abundances of elements in the universe, a few minor natural processes continue to produce very small numbers of new nuclides on Earth. These nuclides contribute little to their abundances, but may account for the presence of specific new nuclei. These nuclides are produced via radiogenesis (decay) of long-lived, heavy, primordial radionuclides such as uranium and thorium. Cosmic ray bombardment of elements on Earth also contribute to the presence of rare, short-lived atomic species called cosmogenic nuclides.