Progenitors and Hydrodynamics of Type II and lb Supernovae
... ilar to that accompanying iron core collapse in larger stars, but with some observational distinctions. First, the density gradient at the edge of the ONeMg core is very steep. Little 56 Ni will be produced. Mayle & Wilson (1988) calculate ~0.002 M 0 of 56 Ni for a model of this sort. Also the envel ...
... ilar to that accompanying iron core collapse in larger stars, but with some observational distinctions. First, the density gradient at the edge of the ONeMg core is very steep. Little 56 Ni will be produced. Mayle & Wilson (1988) calculate ~0.002 M 0 of 56 Ni for a model of this sort. Also the envel ...
LIAC_VanGrootel - ORBi
... convective He-burning core (I), radiative He mantle (II) and very thin H-rich envelope (III) lifetime of ~ 108 yr (100 Myr) on EHB, then evolve directly as low-mass white dwarfs ~50% of sdB stars reside in binary systems, generally in close orbit (Porb 10 days) ...
... convective He-burning core (I), radiative He mantle (II) and very thin H-rich envelope (III) lifetime of ~ 108 yr (100 Myr) on EHB, then evolve directly as low-mass white dwarfs ~50% of sdB stars reside in binary systems, generally in close orbit (Porb 10 days) ...
Progenitor systems of Type Ia Supernovae: mergers of white dwarfs
... billions of years to reach us. Therefore, they enable us to probe the Universe at it was billions of years younger. A special property of type Ia supernovae is that their intrinsic brightness can be inferred without knowing their distance. This makes them a great tool to measure cosmological distanc ...
... billions of years to reach us. Therefore, they enable us to probe the Universe at it was billions of years younger. A special property of type Ia supernovae is that their intrinsic brightness can be inferred without knowing their distance. This makes them a great tool to measure cosmological distanc ...
Fulltext
... (4) scalar fields (which may account for the origin of masses). It is therefore natural to ask whether there exist stable stellar configurations other than dwarfs, neutron stars, and black holes. The central density of a typical neutron star is often greater than several times the nuclear matter den ...
... (4) scalar fields (which may account for the origin of masses). It is therefore natural to ask whether there exist stable stellar configurations other than dwarfs, neutron stars, and black holes. The central density of a typical neutron star is often greater than several times the nuclear matter den ...
Parameters of massive stars in the Milky Way and nearby galaxies
... atmospheres that include sphericity, mass-loss and line-blanketing, in addition to NLTE. The combination of all these factors results in temperatures that are much cooler than those hitherto assumed. Vacca et al. (1996) presented a compilation of the spectroscopic determinations of effective temper ...
... atmospheres that include sphericity, mass-loss and line-blanketing, in addition to NLTE. The combination of all these factors results in temperatures that are much cooler than those hitherto assumed. Vacca et al. (1996) presented a compilation of the spectroscopic determinations of effective temper ...
X-ray binaries
... Accretion and B field • When a strongly magnetic neutron star accretes plasma from a companion star or the interstellar medium, its magnetic field becomes dynamically important close to the stellar surface and determines the properties of the accretion flow. The radius at which the effects of the magn ...
... Accretion and B field • When a strongly magnetic neutron star accretes plasma from a companion star or the interstellar medium, its magnetic field becomes dynamically important close to the stellar surface and determines the properties of the accretion flow. The radius at which the effects of the magn ...
an aluminum/calcium-rich, iron-poor, white dwarf star
... (dM/dt) of all the elements listed in Tables 2 and 3. Assuming that accretion is in the steady-state phase, we derive total mass accretion rates of 3 × 108 and 6 × 108 g s−1 for G149-28 and NLTT 43806, respectively. In comparison, utilizing a different procedure, Farihi et al. (2009) derived rates o ...
... (dM/dt) of all the elements listed in Tables 2 and 3. Assuming that accretion is in the steady-state phase, we derive total mass accretion rates of 3 × 108 and 6 × 108 g s−1 for G149-28 and NLTT 43806, respectively. In comparison, utilizing a different procedure, Farihi et al. (2009) derived rates o ...
Evolutionary and pulsational properties of white dwarf stars
... White dwarf stars have captured the attention of astronomers since their early discovery in 1914, when H. Russell (Russell 1914) noticed that the star now known as 40 Eridani B was located well below the main sequence on the Hertzsprung–Russell diagram (Fig. 1). He rapidly realized that this star wa ...
... White dwarf stars have captured the attention of astronomers since their early discovery in 1914, when H. Russell (Russell 1914) noticed that the star now known as 40 Eridani B was located well below the main sequence on the Hertzsprung–Russell diagram (Fig. 1). He rapidly realized that this star wa ...
Accreting neutron stars: strong gravity and type I bursts - UvA-DARE
... of a progenitor with 8 M⊙ . M . 30 M⊙ (although higher masses have been suggested, see Smartt, 2009), or from collapsing white dwarves. Despite the fact that our understanding has being continuously increasing, neutron stars excite so much interest because many questions concerning the details of th ...
... of a progenitor with 8 M⊙ . M . 30 M⊙ (although higher masses have been suggested, see Smartt, 2009), or from collapsing white dwarves. Despite the fact that our understanding has being continuously increasing, neutron stars excite so much interest because many questions concerning the details of th ...
Sardinia_SA - Mullard Space Science Laboratory
... • Light curves are strongly variable on orbital timescales • If accretion is occurring mainly near one magnetic pole, then, depending on the latitude of the accretion region, this can come into view and disappear over the limb as the synchronised binary rotates: “bright” and “faint” phases ...
... • Light curves are strongly variable on orbital timescales • If accretion is occurring mainly near one magnetic pole, then, depending on the latitude of the accretion region, this can come into view and disappear over the limb as the synchronised binary rotates: “bright” and “faint” phases ...
Evolution of supermassive stars as a pathway to black hole formation
... Key words: black hole physics — accretion, accretion discs — galaxies: nuclei — quasars: general ...
... Key words: black hole physics — accretion, accretion discs — galaxies: nuclei — quasars: general ...
Monte Carlo simulations of the disc white dwarf population
... For that purpose we will use a Monte Carlo method, coupled with Bayesian inference techniques, within the frame of a consistent model of Galactic evolution, and using improved cooling sequences. To be precise, we want speci®c answers for the following questions. Are the kinematics of the derived whi ...
... For that purpose we will use a Monte Carlo method, coupled with Bayesian inference techniques, within the frame of a consistent model of Galactic evolution, and using improved cooling sequences. To be precise, we want speci®c answers for the following questions. Are the kinematics of the derived whi ...
Nucleosynthesis in asymptotic giant branch stars
... the so called hot bottom burning (HBB). This is an envelope convective burning, where the convective envelope reaches the top of the H-burning shell (see Fig. 2). But such a process does not occur unless the initial stellar mass is above 4 M¯ in case of initial solar-like metallicity, but it could a ...
... the so called hot bottom burning (HBB). This is an envelope convective burning, where the convective envelope reaches the top of the H-burning shell (see Fig. 2). But such a process does not occur unless the initial stellar mass is above 4 M¯ in case of initial solar-like metallicity, but it could a ...
ASTR 31: Descriptive Astronomy
... Helium capture The triple-alpha reaction and the major carbon and oxygen burning reactions are helium capture reactions. The capture of helium nuclei continues until silicon is created, at which point the supply of helium nuclei in the star’s core is depleted: 20Ne + 4He → 24Mg + 24Mg + 4He ...
... Helium capture The triple-alpha reaction and the major carbon and oxygen burning reactions are helium capture reactions. The capture of helium nuclei continues until silicon is created, at which point the supply of helium nuclei in the star’s core is depleted: 20Ne + 4He → 24Mg + 24Mg + 4He ...
Ch. 19 - Astro1010
... Often as a large star ages much of the fuel is used up and deposited as ‘ash’ in the iron core. The inward pressure on the iron core is enormous, due to the high mass of the star. As the core continues to become more and more dense, the protons react with one another to become neutrons + a flood of ...
... Often as a large star ages much of the fuel is used up and deposited as ‘ash’ in the iron core. The inward pressure on the iron core is enormous, due to the high mass of the star. As the core continues to become more and more dense, the protons react with one another to become neutrons + a flood of ...
The K2-ESPRINT Project III: A Close-in Super
... corrected light curves ready for our planet search routines. In particular, field 3 targets were observed for 69 days, from 2014 November 15 through 2015 January 23. The dataset was split into 9 segments with a duration of approximately 7.5 days each. Because of the faintness of K2-28, we defined an ...
... corrected light curves ready for our planet search routines. In particular, field 3 targets were observed for 69 days, from 2014 November 15 through 2015 January 23. The dataset was split into 9 segments with a duration of approximately 7.5 days each. Because of the faintness of K2-28, we defined an ...
Which Stars Form Black Holes and Neutron Stars?
... The third method is to identify compact objects that are members of coeval populations of stars, for which the maximum initial masses of stars still present is also a lower limit on the masses of stars that have undergone supernovae. Unfortunately, neutron stars and black holes may receive kicks at ...
... The third method is to identify compact objects that are members of coeval populations of stars, for which the maximum initial masses of stars still present is also a lower limit on the masses of stars that have undergone supernovae. Unfortunately, neutron stars and black holes may receive kicks at ...
History of Star Formation in Local Galaxies
... 20 km/s), most dSphs have formed stars over many Gyr. Some only ran out of gas in the past 1 Gyr. Despite actively forming stars over most of the Hubble time, the stars in dwarfs have nearly a constant metallicity. The galaxies enrich quickly to an [Fe/H] that correlates well with the galaxy’s total ...
... 20 km/s), most dSphs have formed stars over many Gyr. Some only ran out of gas in the past 1 Gyr. Despite actively forming stars over most of the Hubble time, the stars in dwarfs have nearly a constant metallicity. The galaxies enrich quickly to an [Fe/H] that correlates well with the galaxy’s total ...
Chapter 8
... know how stars are formed, how can we hope to understand their evolution? The reason that stellar evolution is a much more quantitative and predictive branch of astrophysics than star formation was already alluded to in Chapter 6. Once a recently formed star settles into hydrostatic and thermal equi ...
... know how stars are formed, how can we hope to understand their evolution? The reason that stellar evolution is a much more quantitative and predictive branch of astrophysics than star formation was already alluded to in Chapter 6. Once a recently formed star settles into hydrostatic and thermal equi ...
Chapter 12 Pre-supernova evolution of massive stars
... Pre-supernova evolution of massive stars We have seen that low- and intermediate-mass stars (with masses up to ≈ 8 M⊙ ) develop carbonoxygen cores that become degenerate after central He burning. As a consequence the maximum core temperature reached in these stars is smaller than the temperature req ...
... Pre-supernova evolution of massive stars We have seen that low- and intermediate-mass stars (with masses up to ≈ 8 M⊙ ) develop carbonoxygen cores that become degenerate after central He burning. As a consequence the maximum core temperature reached in these stars is smaller than the temperature req ...
Physics of Stars and the Measurement Data: Part III
... isotopes 41 H, 51 H, 61 H have short time of life and emit electrons with energy more than 20 Mev. The decay of helium isotopes 62 He, 82 He, 10 2 He have the times of life, which can reach tenth part of the seconds. Stars have the time of life about billions years and the lines of their spectrum of ...
... isotopes 41 H, 51 H, 61 H have short time of life and emit electrons with energy more than 20 Mev. The decay of helium isotopes 62 He, 82 He, 10 2 He have the times of life, which can reach tenth part of the seconds. Stars have the time of life about billions years and the lines of their spectrum of ...
Bamberg_VanGrootel - ORBi
... For binary stars: ok, thanks to stellar companion For single stars, it’s more difficult: ...
... For binary stars: ok, thanks to stellar companion For single stars, it’s more difficult: ...
Draft paper (Published in ApJL)
... This may be seen in the right-hand panels, which show the z-component of the gas velocity along the cylinder delineated by the vertical lines in the left-hand panel. The cylinder, whose radius is chosen to be the same as the virial radius of the galaxy, is aligned with the z axis and therefore rough ...
... This may be seen in the right-hand panels, which show the z-component of the gas velocity along the cylinder delineated by the vertical lines in the left-hand panel. The cylinder, whose radius is chosen to be the same as the virial radius of the galaxy, is aligned with the z axis and therefore rough ...
U P C NIVERSITAT
... marked contrast to the case of core-collapse supernovae, whose stellar progenitors are highly-luminous, massive stars. Observational evidence favors the double-degenerate channel, but significant discrepancies exist between observations and theory. There are approximately a few hundred million doubl ...
... marked contrast to the case of core-collapse supernovae, whose stellar progenitors are highly-luminous, massive stars. Observational evidence favors the double-degenerate channel, but significant discrepancies exist between observations and theory. There are approximately a few hundred million doubl ...
Stellar Evolution
... … another one, observed Energy equivalent to the entire mass by us with the MDM 1.3 m of the sun (E = mc2), converted into gamma-rays in just a few seconds! telescope on Kitt Peak! ...
... … another one, observed Energy equivalent to the entire mass by us with the MDM 1.3 m of the sun (E = mc2), converted into gamma-rays in just a few seconds! telescope on Kitt Peak! ...