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, ...
L95 IRON-RICH EJECTA IN THE SUPERNOVA
... which evaluates to M ∼ 1.1MCh for r p 3, r p 8.6 pc, and a mean ambient density of 0.5 cm⫺3 (Ghavamian et al. 2002). At this time, the entire ejecta have been thermalized, the reverse shock has just reached the center, and the ejecta are moving outward relatively slowly at ⱗ100 km s⫺1. For our sec ...
... which evaluates to M ∼ 1.1MCh for r p 3, r p 8.6 pc, and a mean ambient density of 0.5 cm⫺3 (Ghavamian et al. 2002). At this time, the entire ejecta have been thermalized, the reverse shock has just reached the center, and the ejecta are moving outward relatively slowly at ⱗ100 km s⫺1. For our sec ...
Galactic Evolution of Silicon Isotopes: Applications to
... to stellar mass. Variations are caused by di†erences in the density structure of the presupernova stars, the sensitivity of the presupernova models to the interaction of the various convective zones during oxygen and silicon burning, the uncertainty in modeling the explosion mechanism, and the mass ...
... to stellar mass. Variations are caused by di†erences in the density structure of the presupernova stars, the sensitivity of the presupernova models to the interaction of the various convective zones during oxygen and silicon burning, the uncertainty in modeling the explosion mechanism, and the mass ...
Galactic Evolution of Silicon Isotopes: Application to Presolar SiC
... along a line in a three-isotope plot if the AGB initial silicon isotopic compositions lay along a line. Nor are AGB stars the only potential sources for SiC. Wolf-Rayet carbon winds and postsupernova helium shells of massive stars provide other potential sources for SiC grains. As an example, two WC ...
... along a line in a three-isotope plot if the AGB initial silicon isotopic compositions lay along a line. Nor are AGB stars the only potential sources for SiC. Wolf-Rayet carbon winds and postsupernova helium shells of massive stars provide other potential sources for SiC grains. As an example, two WC ...
presentation (PPT format)
... Elliptical galaxies are nearly devoid of interstellar gas and dust, and so star formation is severely inhibited They are mostly composed of old, red, Population II with little metals ...
... Elliptical galaxies are nearly devoid of interstellar gas and dust, and so star formation is severely inhibited They are mostly composed of old, red, Population II with little metals ...
The star formation history of galaxies in 3D: CALIFA perspective
... (Blanton & Moustakas 2009), following well the Hubble tuning-fork diagram. The bulge fraction seems to be one of the main physical parameters that produce the Hubble sequence, increasing from late to early spirals. In this scheme, S0 galaxies are a transition class between the spiral classes and the ...
... (Blanton & Moustakas 2009), following well the Hubble tuning-fork diagram. The bulge fraction seems to be one of the main physical parameters that produce the Hubble sequence, increasing from late to early spirals. In this scheme, S0 galaxies are a transition class between the spiral classes and the ...
Document
... • Long-Soft bursts: Collapsar model • Death of a massive (> 40 Msun), rotating, low-metallicity star: • Massive for a corecollapse forming a BH • Rotating to drive a pair of jet along the rotation axis • Low-metallicity to retain mass an angular momentum SASS ...
... • Long-Soft bursts: Collapsar model • Death of a massive (> 40 Msun), rotating, low-metallicity star: • Massive for a corecollapse forming a BH • Rotating to drive a pair of jet along the rotation axis • Low-metallicity to retain mass an angular momentum SASS ...
Elliptical galaxies
... luminosity (E’s), and compact ellipticals (cE’s), covering a range in absolute magnitudes from MB ~−23 to MB ~−15. ...
... luminosity (E’s), and compact ellipticals (cE’s), covering a range in absolute magnitudes from MB ~−23 to MB ~−15. ...
Stellar Evolution Nucleosynthesis
... • Fusion progresses no further in a low-mass star because the core temperature never grows hot enough for fusion of heavier elements. (The sun is massive enough to fuse some He with C to make oxygen, but most of the C and O will be trapped forever in the white dwarf). • Degeneracy pressure supports ...
... • Fusion progresses no further in a low-mass star because the core temperature never grows hot enough for fusion of heavier elements. (The sun is massive enough to fuse some He with C to make oxygen, but most of the C and O will be trapped forever in the white dwarf). • Degeneracy pressure supports ...
Injection mechanisms of short-lived radionuclides and their
... (Bizzarro et al., 2007; Quitté and Markowski, 2007), however, did not find the expected excess 60Ni in SAH99555, a basaltic angrite with a well-constrained Pb–Pb age of 4564.55 ± 0.16 Myr (Connelly et al., 2008b) and evidence for live 26Al at the time of its crystallization (Baker et al., 2005). The ...
... (Bizzarro et al., 2007; Quitté and Markowski, 2007), however, did not find the expected excess 60Ni in SAH99555, a basaltic angrite with a well-constrained Pb–Pb age of 4564.55 ± 0.16 Myr (Connelly et al., 2008b) and evidence for live 26Al at the time of its crystallization (Baker et al., 2005). The ...
Review: How does a star`s mass determine its life story?
... Two Types of Supernova Massive star supernova: ...
... Two Types of Supernova Massive star supernova: ...
neutron star
... “In this artist's illustration, two distant galaxies formed about 2 billion years after the big bang are caught in the afterglow of GRB090323, a gamma-ray burst seen across the Universe. Shining through its own host galaxy and another nearby galaxy, the alignment of gamma-ray burst and galaxies was ...
... “In this artist's illustration, two distant galaxies formed about 2 billion years after the big bang are caught in the afterglow of GRB090323, a gamma-ray burst seen across the Universe. Shining through its own host galaxy and another nearby galaxy, the alignment of gamma-ray burst and galaxies was ...
Title: Binary interaction dominates the evolution of massive stars
... pairs (π = -0.55 ± 0.2) and a uniform distribution of the mass ratio (κ = -0.1 ± 0.6) for binaries with periods up to about nine years. Comparison of the intrinsic, simulated and observed cumulative distributions of the orbital parameters shows that observational biases are mostly restricted to the ...
... pairs (π = -0.55 ± 0.2) and a uniform distribution of the mass ratio (κ = -0.1 ± 0.6) for binaries with periods up to about nine years. Comparison of the intrinsic, simulated and observed cumulative distributions of the orbital parameters shows that observational biases are mostly restricted to the ...
Super and massive AGB stars-IV. Final fates
... between 5.0 and 10.0 M⊙ for metallicities spanning the range Z=0.02−0.0001. We probe the mass limits Mup , Mn and Mmass , the minimum masses for the onset of carbon burning, the formation of a neutron star, and the iron core-collapse supernovae respectively, to constrain the white dwarf/electron-cap ...
... between 5.0 and 10.0 M⊙ for metallicities spanning the range Z=0.02−0.0001. We probe the mass limits Mup , Mn and Mmass , the minimum masses for the onset of carbon burning, the formation of a neutron star, and the iron core-collapse supernovae respectively, to constrain the white dwarf/electron-cap ...
Tuomas Kangas
... ‘standard candle’. These SNe were instrumental in discovering the accelerating expansion of the universe and the existence of dark energy, which led to the Nobel Prize in Physics in the year 2011. However, uncertainties still remain in the progenitor scenarios of thermonuclear SNe. The most importan ...
... ‘standard candle’. These SNe were instrumental in discovering the accelerating expansion of the universe and the existence of dark energy, which led to the Nobel Prize in Physics in the year 2011. However, uncertainties still remain in the progenitor scenarios of thermonuclear SNe. The most importan ...
white dwarfs and the age of the universe
... fraction of them can change their external aspect during the evolution [10]. Standard evolution theory predicts that typical field white dwarfs have a core mass in the range of 0.5 to 1.0 M⊙ made of a mixture of carbon and oxygen surrounded by a helium mantle of MHe ≃ 10−2 MWD , surrounded itself by ...
... fraction of them can change their external aspect during the evolution [10]. Standard evolution theory predicts that typical field white dwarfs have a core mass in the range of 0.5 to 1.0 M⊙ made of a mixture of carbon and oxygen surrounded by a helium mantle of MHe ≃ 10−2 MWD , surrounded itself by ...
Nucleosynthesis and Chemical Evolution of Oxygen
... To analyze the yields from massive stars, we consider a single model. While this is only one particular model, its yields are fairly representative of the ejecta from any star more than ten times the mass of the Sun. Chemical evolution models using detailed stellar model yields have long shown that ...
... To analyze the yields from massive stars, we consider a single model. While this is only one particular model, its yields are fairly representative of the ejecta from any star more than ten times the mass of the Sun. Chemical evolution models using detailed stellar model yields have long shown that ...
Type Ia Supernovae
... Ic have been attributed to these events. This thesis, however is dedicated to the second 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 sta ...
... Ic have been attributed to these events. This thesis, however is dedicated to the second 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 sta ...
SHELL BURNING STARS: Red Giants and Red Supergiants
... composition. For example, the core may have no hydrogen, and mostly helium, while the envelope may be hydrogen rich. As a result, there is a nuclear burning shell at the bottom of the envelope; hydrogen burning shell in our example. The heat generated in the shell is diffusing out with radiation, an ...
... composition. For example, the core may have no hydrogen, and mostly helium, while the envelope may be hydrogen rich. As a result, there is a nuclear burning shell at the bottom of the envelope; hydrogen burning shell in our example. The heat generated in the shell is diffusing out with radiation, an ...
LATE STAGES OF CLOSE BINARY SYSTEMS 1. Introduction The X
... 1976). This limit may, in real life, be somewhat higher still if one takes into account that helium stars more massive than about 4 A f o r 5Af are likely to be identified with WolfRayet stars, which are observed to undergo substantial mass loss by stellar wind. Mass loss rates between \QT*M^yx' and ...
... 1976). This limit may, in real life, be somewhat higher still if one takes into account that helium stars more massive than about 4 A f o r 5Af are likely to be identified with WolfRayet stars, which are observed to undergo substantial mass loss by stellar wind. Mass loss rates between \QT*M^yx' and ...
Explosion and Systematics for Core
... Woosley et al. [2002], Heger et al. [2003] extended the work of Woosley and Weaver [1995], including the effect of mass loss during the presupernova evolution which was neglected in Woosley and Weaver [1995] and increasing the number of progenitors studied. The predictions from all these works are s ...
... Woosley et al. [2002], Heger et al. [2003] extended the work of Woosley and Weaver [1995], including the effect of mass loss during the presupernova evolution which was neglected in Woosley and Weaver [1995] and increasing the number of progenitors studied. The predictions from all these works are s ...
A Simple Model for r-Process Scatter and Halo Evolution
... Neutron capture processes dominate the nucleosynthesis of elements beyond the iron peak. The physics of two neutron capture mechanisms has long been understood, and the astrophysical site for slow neutron capture nucleosynthesis (the s-process) has been shown to be low-mass stars (e.g., Busso, Galli ...
... Neutron capture processes dominate the nucleosynthesis of elements beyond the iron peak. The physics of two neutron capture mechanisms has long been understood, and the astrophysical site for slow neutron capture nucleosynthesis (the s-process) has been shown to be low-mass stars (e.g., Busso, Galli ...
18_Testbank - Lick Observatory
... 7) Suppose a white dwarf is gaining mass because of accretion in a binary system. What happens if the mass someday reaches the 1.4-solar-mass limit? A) The white dwarf undergoes a catastrophic collapse, leading to a type of supernova that is somewhat different from that which occurs in a massive sta ...
... 7) Suppose a white dwarf is gaining mass because of accretion in a binary system. What happens if the mass someday reaches the 1.4-solar-mass limit? A) The white dwarf undergoes a catastrophic collapse, leading to a type of supernova that is somewhat different from that which occurs in a massive sta ...
X-ray Observations of Cosmic Accelerators Greg Madejski SLAC/KIPAC
... consistent with the above * Multiple observations of SNR separated by ~ years also clearly show the expansion ...
... consistent with the above * Multiple observations of SNR separated by ~ years also clearly show the expansion ...
Supernova
A supernova is a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the Sun or any ordinary star is expected to emit over its entire life span, before fading from view over several weeks or months. The extremely luminous burst of radiation expels much or all of a star's material at a velocity of up to 7007300000000000000♠30,000 km/s (10% of the speed of light), driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. Supernovae are potentially strong galactic sources of gravitational waves. A great proportion of primary cosmic rays comes from supernovae.Supernovae are more energetic than novae. Nova means ""new"" in Latin, referring to what appears to be a very bright new star shining in the celestial sphere; the prefix ""super-"" distinguishes supernovae from ordinary novae, which are far less luminous. The word supernova was coined by Walter Baade and Fritz Zwicky in 1931. It is pronounced /ˌsuːpərnoʊvə/ with the plural supernovae /ˌsuːpərnoʊviː/ or supernovas (abbreviated SN, plural SNe after ""supernovae"").Supernovae can be triggered in one of two ways: by the sudden re-ignition of nuclear fusion in a degenerate star; or by the gravitational collapse of the core of a massive star. In the first case, a degenerate white dwarf may accumulate sufficient material from a companion, either through accretion or via a merger, to raise its core temperature, ignite carbon fusion, and trigger runaway nuclear fusion, completely disrupting the star. In the second case, the core of a massive star may undergo sudden gravitational collapse, releasing gravitational potential energy that can create a supernova explosion.The most recent directly observed supernova in the Milky Way was Kepler's Star of 1604 (SN 1604); remnants of two more recent supernovae have been found retrospectively. Observations in other galaxies indicate that supernovae should occur on average about three times every century in the Milky Way, and that any galactic supernova would almost certainly be observable in modern astronomical equipment. Supernovae play a significant role in enriching the interstellar medium with higher mass elements. Furthermore, the expanding shock waves from supernova explosions can trigger the formation of new stars.