Chemical tagging of three distinct populations of red giants in the
... The abundances of aluminium were derived from GIRAFFE spectra (obtained with FLAMES, Pasquini et al. 2002, mounted at the ESO VLT-UT2 telescope) with the high resolution grating HR21. This set-up is centred at 8757 Å and the spectral resolution is R=17,300 at the center of spectra. The pointing was ...
... The abundances of aluminium were derived from GIRAFFE spectra (obtained with FLAMES, Pasquini et al. 2002, mounted at the ESO VLT-UT2 telescope) with the high resolution grating HR21. This set-up is centred at 8757 Å and the spectral resolution is R=17,300 at the center of spectra. The pointing was ...
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR
... evolution of more distant galaxies to date (Matteucci & Tosi 1985). So far, only a very limited number of elements can be examined and quantified when using this approach. The chemical evolution of a galaxy depends on the contributions of all its constituents, e.g., SNe type Ia and II, high mass sta ...
... evolution of more distant galaxies to date (Matteucci & Tosi 1985). So far, only a very limited number of elements can be examined and quantified when using this approach. The chemical evolution of a galaxy depends on the contributions of all its constituents, e.g., SNe type Ia and II, high mass sta ...
arXiv:astro-ph/0612072v1 4 Dec 2006 Theory of core
... The core bounce with the formation of a shock wave is the starting point of a sequence of events that ultimately triggers a supernova explosion (Fig. 1, middle left panel), but the exact mechanism of the explosion and the crucial ingredients of this physically appealing scenario are still uncertain ...
... The core bounce with the formation of a shock wave is the starting point of a sequence of events that ultimately triggers a supernova explosion (Fig. 1, middle left panel), but the exact mechanism of the explosion and the crucial ingredients of this physically appealing scenario are still uncertain ...
Document
... Mystery remains: Of the many possibilities for combining quarks with colour into colourless hadrons, only two configurations were found, till now… ...
... Mystery remains: Of the many possibilities for combining quarks with colour into colourless hadrons, only two configurations were found, till now… ...
The Celestial Origin of Atoms
... Aims and aspirations of nuclear astrophysics The aim of nuclear astrophysics is threefold. Firstly, it seeks to determine the mechanisms whereby the various nuclear species occurring in nature are built up, from deuterium with its two nucleons to uranium with 238 nucleons. Secondly, it seeks to iden ...
... Aims and aspirations of nuclear astrophysics The aim of nuclear astrophysics is threefold. Firstly, it seeks to determine the mechanisms whereby the various nuclear species occurring in nature are built up, from deuterium with its two nucleons to uranium with 238 nucleons. Secondly, it seeks to iden ...
Title
... Novae (exploding stars) – a nova is a previously invisible or much fainter star that suddenly brightens manyfold and then fades after a few days or weeks A look at its spectra shows strong atomic emission lines, evidence of an expanding gas cloud ...
... Novae (exploding stars) – a nova is a previously invisible or much fainter star that suddenly brightens manyfold and then fades after a few days or weeks A look at its spectra shows strong atomic emission lines, evidence of an expanding gas cloud ...
What We Might Learn from Gravitational Waves
... Need both GW+EM to fully understand relativistic sources GW+EM help identify sources (in either direction) ...
... Need both GW+EM to fully understand relativistic sources GW+EM help identify sources (in either direction) ...
Life, the Universe, and almost Everything: Signs of Cosmic Design?
... For explanations, these descriptions, embedded and joined in a theory, should suffice in principle. Thus, the usual scheme of explanations in physics is roughly like this: Given some boundary conditions and laws (including constants) or a theory (which connects or unifies different laws), i.e. the e ...
... For explanations, these descriptions, embedded and joined in a theory, should suffice in principle. Thus, the usual scheme of explanations in physics is roughly like this: Given some boundary conditions and laws (including constants) or a theory (which connects or unifies different laws), i.e. the e ...
The chemical composition of TS 01, the most oxygen
... in conflict with what is actually observed in the UV. HST observations were obtained in 2003 and presented in a short, preliminary version by Jacoby et al. (2006). Those authors quoted an oxygen abundance of 1/30−1/40 solar, and carbon and nitrogen abundances roughly 1/10 solar. Before embarking on ...
... in conflict with what is actually observed in the UV. HST observations were obtained in 2003 and presented in a short, preliminary version by Jacoby et al. (2006). Those authors quoted an oxygen abundance of 1/30−1/40 solar, and carbon and nitrogen abundances roughly 1/10 solar. Before embarking on ...
Chapter 31: Galaxies and the Universe
... speculated that it might also have spiral arms, as many other galaxies populated by stars, many of do. This was very difficult to prove, however, because astronomers which are obscured by dust. have no way to get outside of the galaxy and look down on the disk. Astronomers have used hydrogen atoms t ...
... speculated that it might also have spiral arms, as many other galaxies populated by stars, many of do. This was very difficult to prove, however, because astronomers which are obscured by dust. have no way to get outside of the galaxy and look down on the disk. Astronomers have used hydrogen atoms t ...
Generation of Cosmological Perturbations by a First
... phase to a broken phase is of strongly first-order. However a very important issue of cosmology has been left out of arguments: One has to explain how and why the universe has attained the large scale inhomogeneities of matter distribution such as superclusters of galaxies. 9 ) This problem must be ...
... phase to a broken phase is of strongly first-order. However a very important issue of cosmology has been left out of arguments: One has to explain how and why the universe has attained the large scale inhomogeneities of matter distribution such as superclusters of galaxies. 9 ) This problem must be ...
Astronomy Astrophysics
... Furthermore, and perhaps even more importantly, individual age determinations are possible for these stars using long-lived radioactive isotopes, such as 232 Th (half-life 14.05 Gyr) or 238 U (4.468 Gyr). By comparing the abundance ratio of these elements relative to a stable r-process element of si ...
... Furthermore, and perhaps even more importantly, individual age determinations are possible for these stars using long-lived radioactive isotopes, such as 232 Th (half-life 14.05 Gyr) or 238 U (4.468 Gyr). By comparing the abundance ratio of these elements relative to a stable r-process element of si ...
The Hamburg/ESO R-process Enhanced Star survey (HERES)
... Furthermore, and perhaps even more importantly, individual age determinations are possible for these stars using long-lived radioactive isotopes, such as 232 Th (half-life 14.05 Gyr) or 238 U (4.468 Gyr). By comparing the abundance ratio of these elements relative to a stable r-process element of si ...
... Furthermore, and perhaps even more importantly, individual age determinations are possible for these stars using long-lived radioactive isotopes, such as 232 Th (half-life 14.05 Gyr) or 238 U (4.468 Gyr). By comparing the abundance ratio of these elements relative to a stable r-process element of si ...
Advanced Topics in Cosmology: A Pedagogical Introduction
... universe decreases as T ∝ t−1/2 . As the universe expands, a time will come when (t = teq , a = aeq and z = zeq , say) the matter energy density will be comparable to radiation energy density. For the parameters described above, (1 + zeq ) = ΩN R /ΩR ≃ 4 × 104 ΩDM h2 . At lower redshifts, matter wil ...
... universe decreases as T ∝ t−1/2 . As the universe expands, a time will come when (t = teq , a = aeq and z = zeq , say) the matter energy density will be comparable to radiation energy density. For the parameters described above, (1 + zeq ) = ΩN R /ΩR ≃ 4 × 104 ΩDM h2 . At lower redshifts, matter wil ...
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 ...
S-process in extremely metal-poor, low-mass stars
... The positive correlation between carbon and barium abundances observed in EMP stars indicates that carbon and s-process elements might have a common production site (Aoki et al. 2002; Suda et al. 2004, 2011). Stars with a metallicity of [Fe/H] ≤ −2.5 in the mass range of 1.2 M < M ≤ 3.0 M also exp ...
... The positive correlation between carbon and barium abundances observed in EMP stars indicates that carbon and s-process elements might have a common production site (Aoki et al. 2002; Suda et al. 2004, 2011). Stars with a metallicity of [Fe/H] ≤ −2.5 in the mass range of 1.2 M < M ≤ 3.0 M also exp ...
The 13C(α,n)16O reaction rate. Recent estimates, new
... because of thermonuclear fusion reactions occurring in their interior producing electromagnetic energy and neutrinos. They are considered as the forges of universe because the whole set of elements (excluding initial abundances of nuclei lighter than 12 C, which are created during the first minutes ...
... because of thermonuclear fusion reactions occurring in their interior producing electromagnetic energy and neutrinos. They are considered as the forges of universe because the whole set of elements (excluding initial abundances of nuclei lighter than 12 C, which are created during the first minutes ...
Cosmological Implications of Trace
... atomic abundance 10−2 ) are fairly abundant elements created by later stellar nucleosynthesis that have a higher electron affinity (Rienstra-Kiracofe et al. [2002]) than H, while F (electron affinity −3.40eV , atomic abundance 4x10−7 ) and Cl (electron affinity −3.61eV , atomic abundance 10−6 ) are ...
... atomic abundance 10−2 ) are fairly abundant elements created by later stellar nucleosynthesis that have a higher electron affinity (Rienstra-Kiracofe et al. [2002]) than H, while F (electron affinity −3.40eV , atomic abundance 4x10−7 ) and Cl (electron affinity −3.61eV , atomic abundance 10−6 ) are ...
Kim - cosmo 05
... • N-genesis and ν–genesis seem to be the plausible ones since the observed neutrino masses need R-handed neutrinos. Survival hypothesis sides with N-genesis. Q-genesis depends on the unobserved Q, but this may be needed in solutions of the strong CP problem. Also, it appears in E6 and trinification ...
... • N-genesis and ν–genesis seem to be the plausible ones since the observed neutrino masses need R-handed neutrinos. Survival hypothesis sides with N-genesis. Q-genesis depends on the unobserved Q, but this may be needed in solutions of the strong CP problem. Also, it appears in E6 and trinification ...
Astro-2: History of the Universe
... with a given precision, equal to the precision with which you know the Hubble Constant • Redshifts can be measured very precisely, much more precisely than you know your height!!! For this reason astronomers generally say a galaxy is at a redshift z=0.4231, rather than quoting its distance • Dista ...
... with a given precision, equal to the precision with which you know the Hubble Constant • Redshifts can be measured very precisely, much more precisely than you know your height!!! For this reason astronomers generally say a galaxy is at a redshift z=0.4231, rather than quoting its distance • Dista ...
Intelligent Life in the Universe
... Uncertainties! Important - each term in the Drake equation (probably) gets more uncertain when proceeding from left to right. For lack of a better example we have adopted an Earth/human bias when estimating various terms. We do not know the uncertainties. ...
... Uncertainties! Important - each term in the Drake equation (probably) gets more uncertain when proceeding from left to right. For lack of a better example we have adopted an Earth/human bias when estimating various terms. We do not know the uncertainties. ...
Thermodynamic properties of nuclear" pasta" in neutron star crusts
... nuclei. The crystalline region of the star (not) including a gas of the dripped neutrons is usually referred to as an inner (outer) crust. In the deepest region of the inner crust, corresponding to densities just below the normal saturation density ρs ∼ 3 × 1014 g cm−3 , not only are nuclei expected ...
... nuclei. The crystalline region of the star (not) including a gas of the dripped neutrons is usually referred to as an inner (outer) crust. In the deepest region of the inner crust, corresponding to densities just below the normal saturation density ρs ∼ 3 × 1014 g cm−3 , not only are nuclei expected ...
Expanding the Catalog: Considering the Importance
... for burning in the core. For our highest mass stars that develop convective cores the extent of the convective core changes slightly due to the change in electron fraction (the convective core is high enough in temperature to be dominated by electron scattering opacity) and the energy generation by ...
... for burning in the core. For our highest mass stars that develop convective cores the extent of the convective core changes slightly due to the change in electron fraction (the convective core is high enough in temperature to be dominated by electron scattering opacity) and the energy generation by ...
Neutrinos in an Expanding Universe Paper (IOP)
... We have simulated the effects of galaxy formation on the neutrino spectra and densities with a computer program that was especially developed for this purpose. Our simulations show that the lowfield region around the center-of-mass of this galaxy cluster is gradually populated by neutrinos with a dec ...
... We have simulated the effects of galaxy formation on the neutrino spectra and densities with a computer program that was especially developed for this purpose. Our simulations show that the lowfield region around the center-of-mass of this galaxy cluster is gradually populated by neutrinos with a dec ...
Final Stages of Stellar Evolution - supernovae and the synthesis of
... s·cm2 “low” temperatures (∼ 3, 000, 000K) β − decay before next neutron is captured ...
... s·cm2 “low” temperatures (∼ 3, 000, 000K) β − decay before next neutron is captured ...