The Observer`s Guide to the Gamma-Ray Burst
... The luminosity, energetics and shape of the γ-ray pulse of a given GRB can reveal clues to the origin of its high-energy emission, and thus its emission process. Of particular importance is whether the γ-rays emitted by llGRBs arise from the same mechanism as high-luminosity GRBs (i.e. from a jet), ...
... The luminosity, energetics and shape of the γ-ray pulse of a given GRB can reveal clues to the origin of its high-energy emission, and thus its emission process. Of particular importance is whether the γ-rays emitted by llGRBs arise from the same mechanism as high-luminosity GRBs (i.e. from a jet), ...
Galaxies in the Universe: An Introduction, Second Edition
... We have tried to place material which is relatively more difficult or more intricate at the end of each subsection. Students who find some portions heavy going at a first reading are advised to move to the following subsection and return later to the troublesome passage. Some problems have been include ...
... We have tried to place material which is relatively more difficult or more intricate at the end of each subsection. Students who find some portions heavy going at a first reading are advised to move to the following subsection and return later to the troublesome passage. Some problems have been include ...
Spherical planetary nebulae
... of the proposed scenario to the recent finding of extrasolar planets and to the presence of blue horizontal branch stars in globular clusters. Key words. planetary nebulae: general – stars: AGB and post-AGB – stars: mass loss – stars: planetary systems – stars: rotation ...
... of the proposed scenario to the recent finding of extrasolar planets and to the presence of blue horizontal branch stars in globular clusters. Key words. planetary nebulae: general – stars: AGB and post-AGB – stars: mass loss – stars: planetary systems – stars: rotation ...
Full Text
... Het begint al bij de keuze van het type gerecht. Je laat je leiden door je eigen smaak, maar ook het enthousiasme van anderen kan je al op voorhand doen watertanden. Christoffel, hierin speelde je een uitermate belangrijke rol. Het enthousiasme waarmee je de lessen inleiding tot de sterrenkunde op d ...
... Het begint al bij de keuze van het type gerecht. Je laat je leiden door je eigen smaak, maar ook het enthousiasme van anderen kan je al op voorhand doen watertanden. Christoffel, hierin speelde je een uitermate belangrijke rol. Het enthousiasme waarmee je de lessen inleiding tot de sterrenkunde op d ...
Physics of Neutron Star Crusts - Institut d`Astronomie et d
... show there how it can be a site for nuclear reactions. We study its thermal structure during accretion, and briefly review the phenomenon of X-ray bursts. We quantitatively analyze the phenomenon of the deep crustal heating. To construct a neutron star model one needs the equation of state (EoS) of ...
... show there how it can be a site for nuclear reactions. We study its thermal structure during accretion, and briefly review the phenomenon of X-ray bursts. We quantitatively analyze the phenomenon of the deep crustal heating. To construct a neutron star model one needs the equation of state (EoS) of ...
Physics of Neutron Star Crusts
... stars being crucial for selecting a correct dense-matter model. Up to now, progress has been slow and based overwhelmingly on scant observation [183]. The outer layer of neutron stars with density ρ < ρ0 – the neutron star crust – which is the subject of the present review, represents very different ...
... stars being crucial for selecting a correct dense-matter model. Up to now, progress has been slow and based overwhelmingly on scant observation [183]. The outer layer of neutron stars with density ρ < ρ0 – the neutron star crust – which is the subject of the present review, represents very different ...
The effect of dark matter capture on binary stars
... According to the WIMP model, stars in the galaxy travel through a background field of WIMPs that are constantly crossing the star. Some of these WIMPs collide with atomic nuclei inside stars via the weak force interaction. The ones that lose sufficient kinetic energy become bound to the star. Captur ...
... According to the WIMP model, stars in the galaxy travel through a background field of WIMPs that are constantly crossing the star. Some of these WIMPs collide with atomic nuclei inside stars via the weak force interaction. The ones that lose sufficient kinetic energy become bound to the star. Captur ...
Full Text - Digital Access to Scholarship at Harvard
... Still, were dust inert, like dark matter, the Galaxy would be a very different place—the dust plays an outsize role in the physics of the Galaxy. As a solid, dust has a broad range of energy levels and can interact with light over much of a star’s spectrum, whereas atomic hydrogen gas, for instance, ...
... Still, were dust inert, like dark matter, the Galaxy would be a very different place—the dust plays an outsize role in the physics of the Galaxy. As a solid, dust has a broad range of energy levels and can interact with light over much of a star’s spectrum, whereas atomic hydrogen gas, for instance, ...
ULTRA-COMPACT HII REGIONS AND MASSIVE STAR FORMATION
... when resolved. This observationally based definition of HCs is broad enough to apply to any hot, dust/molecular gas–enshrouded object such as UC HII regions, evolved hot stars that have moved into a dense molecular cloud, or massive protostars still undergoing rapid accretion. In this section, I con ...
... when resolved. This observationally based definition of HCs is broad enough to apply to any hot, dust/molecular gas–enshrouded object such as UC HII regions, evolved hot stars that have moved into a dense molecular cloud, or massive protostars still undergoing rapid accretion. In this section, I con ...
Population effects on the red giant clump absolute magnitude, and
... A subtle one is that M RC is assumed either not to depend on I ages (as in Udalski 1998a, 2000), or not to depend on metallicities (as in Udalski 1998b). Thus, the presence of an age±metallicity relation (AMR) in the observational data could be masking a on both parameters, provided that possible de ...
... A subtle one is that M RC is assumed either not to depend on I ages (as in Udalski 1998a, 2000), or not to depend on metallicities (as in Udalski 1998b). Thus, the presence of an age±metallicity relation (AMR) in the observational data could be masking a on both parameters, provided that possible de ...
Thesis (complete) - Research Explorer
... The asymptotic giant branch (AGB) is a phase in the lives of low- and intermediatemass stars (0.8 – 8 M⊙ ) when intense (10−8 – 10−4 M⊙ year−1 ), slow (∼ 10 km s−1 ) winds occur. The conditions for the development of these outflows are met because of the low effective temperatures, large amplitude p ...
... The asymptotic giant branch (AGB) is a phase in the lives of low- and intermediatemass stars (0.8 – 8 M⊙ ) when intense (10−8 – 10−4 M⊙ year−1 ), slow (∼ 10 km s−1 ) winds occur. The conditions for the development of these outflows are met because of the low effective temperatures, large amplitude p ...
Read Claudia`s PhD thesis
... The Galactic globular cluster NGC 2419, one of the brightest and most distant cluster in the MW halo, is a metal poor Oosterhoff type II system suspected to be the relic of an extragalactic system accreted by the MW (see e.g. Mackey & van den Bergh, 2005, and reference therein). We have obtained tim ...
... The Galactic globular cluster NGC 2419, one of the brightest and most distant cluster in the MW halo, is a metal poor Oosterhoff type II system suspected to be the relic of an extragalactic system accreted by the MW (see e.g. Mackey & van den Bergh, 2005, and reference therein). We have obtained tim ...
Evolutionary and pulsational properties of white dwarf stars
... luminosity of Sirius B provided the first estimate of its radius. Because the mass of this star was known to be about 1 M , it was possible to infer the mean density of a white dwarf for the first time: 5 × 104 g/cm3 . The measurement of the gravitational redshift by Adams (1925) resulting from the ...
... luminosity of Sirius B provided the first estimate of its radius. Because the mass of this star was known to be about 1 M , it was possible to infer the mean density of a white dwarf for the first time: 5 × 104 g/cm3 . The measurement of the gravitational redshift by Adams (1925) resulting from the ...
White dwarfs, black holes and neutron stars in close binaries
... and forms a sphere which in its centre has a temperature and pressure high enough to start hydrogen fusion. The star remains in this phase for most of its active life and only in the last ten percent of its active life its conditions change dramatically. Then the hydrogen fuel in its centre is exhau ...
... and forms a sphere which in its centre has a temperature and pressure high enough to start hydrogen fusion. The star remains in this phase for most of its active life and only in the last ten percent of its active life its conditions change dramatically. Then the hydrogen fuel in its centre is exhau ...
Stars and dust in the Galactic Center
... Binned velocity dispersion used for Jeans modeling . . . . . . . Radial and tangential dispersions as function of the radius . . . Average radial velocities from our data and the literature . . . . Data and fits of the Jeans modeling . . . . . . . . . . . . . . . . Binwise median and maximum three-di ...
... Binned velocity dispersion used for Jeans modeling . . . . . . . Radial and tangential dispersions as function of the radius . . . Average radial velocities from our data and the literature . . . . Data and fits of the Jeans modeling . . . . . . . . . . . . . . . . Binwise median and maximum three-di ...
Universe of Motion - Reciprocal System of theory
... are not influenced by the current state of knowledge or opinion in the area involved. (The interpretation of these results may be so influenced, but that is another matter.) If those results conflict with accepted ideas, it is the ideas that must be changed, not the information that the instrument c ...
... are not influenced by the current state of knowledge or opinion in the area involved. (The interpretation of these results may be so influenced, but that is another matter.) If those results conflict with accepted ideas, it is the ideas that must be changed, not the information that the instrument c ...
Systematic Study of Mass Loss in the Evolution of Massive Stars
... are short lived. Nevertheless, their characteristics (e.g. high luminosity, large mass loss rate, complex nuclear burning, final fate, etc.) make them extremely important for many sub-fields of astrophysics. For example, because of their high luminosity, they are the only stars that can be observed ...
... are short lived. Nevertheless, their characteristics (e.g. high luminosity, large mass loss rate, complex nuclear burning, final fate, etc.) make them extremely important for many sub-fields of astrophysics. For example, because of their high luminosity, they are the only stars that can be observed ...
Unfolding the Milky Way bulge - International Max Planck Research
... the red dashed line shows the synthetic spectrum using the best fitting abundance as obtained from our procedure. . . . . . . . . . . . . . . . . . . . . . . . . . Abundance errors associated with the uncertainties in effective temperature (upper left), surface gravity (upper right), metallicity (lo ...
... the red dashed line shows the synthetic spectrum using the best fitting abundance as obtained from our procedure. . . . . . . . . . . . . . . . . . . . . . . . . . Abundance errors associated with the uncertainties in effective temperature (upper left), surface gravity (upper right), metallicity (lo ...
doctoral thesis (Dissertation)
... molecular clouds. Along the galactic equator these clouds are seen as black spots, obscuring the light of background stars. They are relatively cool with temperatures of ten Kelvin in the interior to thousand Kelvin at the outer boundaries, where they are illuminated by other stars. One example of s ...
... molecular clouds. Along the galactic equator these clouds are seen as black spots, obscuring the light of background stars. They are relatively cool with temperatures of ten Kelvin in the interior to thousand Kelvin at the outer boundaries, where they are illuminated by other stars. One example of s ...
Cosmic Rays
... Secondary Isotopes with lifetime ~esc can be used to directly measure the age of CR ...
... Secondary Isotopes with lifetime ~esc can be used to directly measure the age of CR ...
spatially resolved star formation history of milky way satellites
... number of stars formed by a stellar system as a function of time. Is the characterization of when a galaxy or cluster formed its stars and at which chemical composition. The star formation history has historically been derived for a variety of stellar systems in astronomy, to quantitatively assess t ...
... number of stars formed by a stellar system as a function of time. Is the characterization of when a galaxy or cluster formed its stars and at which chemical composition. The star formation history has historically been derived for a variety of stellar systems in astronomy, to quantitatively assess t ...
Th`ese d`astrophysique Chemodynamical Simulations of Evolution
... In this thesis I use chemodynamical simulations to build up a model of evolution of the dust mass in our Galaxy and in dwarf galaxies. I have searched for dust (re-)processing by stars and in the interstellar medium, using both observations and results from semi-analytic models (eliminating few of t ...
... In this thesis I use chemodynamical simulations to build up a model of evolution of the dust mass in our Galaxy and in dwarf galaxies. I have searched for dust (re-)processing by stars and in the interstellar medium, using both observations and results from semi-analytic models (eliminating few of t ...
![arXiv:1601.01542v1 [astro-ph.GA] 7 Jan 2016](http://s1.studyres.com/store/data/017487687_1-243c4cbda96da53325dd347b0c588a3e-300x300.png)
arXiv:1601.01542v1 [astro-ph.GA] 7 Jan 2016
... studies on the topic and also offers the possibility of properly estimating the oxygen distribution across the entire discs over a distance of up to 3-4 disc effective radii. A proper 2D study of the The classification according to morphological type and into inoxygen abundance distribution that ana ...
... studies on the topic and also offers the possibility of properly estimating the oxygen distribution across the entire discs over a distance of up to 3-4 disc effective radii. A proper 2D study of the The classification according to morphological type and into inoxygen abundance distribution that ana ...
DEDUCING THE LIFETIME OF SHORT GAMMA
... ) is the average SFR per stellar mass for a z = 0 elliptical galaxy of stellar mass Mstar . In what follows, we adopt the different galaxy type samples of Bell et al. (2003) derived using the light concentration parameter. The function dF (Mstar , z)/dMstar is obtained by spline interpolation betwee ...
... ) is the average SFR per stellar mass for a z = 0 elliptical galaxy of stellar mass Mstar . In what follows, we adopt the different galaxy type samples of Bell et al. (2003) derived using the light concentration parameter. The function dF (Mstar , z)/dMstar is obtained by spline interpolation betwee ...
The Diffuse Interstellar Bands in History and in the UV
... Previous studies have failed to find convincing evidence of DIBs below 3200 Å (Snow et al. 1977; Seab & Snow 1985). These searches were confined to stars no fainter than about fourth magnitude (Copernicus) to seventh magnitude (International Ultraviolet Explorer). The COS can observe reddened stars t ...
... Previous studies have failed to find convincing evidence of DIBs below 3200 Å (Snow et al. 1977; Seab & Snow 1985). These searches were confined to stars no fainter than about fourth magnitude (Copernicus) to seventh magnitude (International Ultraviolet Explorer). The COS can observe reddened stars t ...
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.