Galaxy Formation
... • What is the dark matter? • What is the dark energy? • What happened in the first 10 s after the Big Bang? • How, in detail, did stars and galaxies form? • How much farther will the simulations go? ...
... • What is the dark matter? • What is the dark energy? • What happened in the first 10 s after the Big Bang? • How, in detail, did stars and galaxies form? • How much farther will the simulations go? ...
ppt - chris.engelbrecht.nithep.ac.za
... • high energy tail of nonthermal electrons yields x-ray synchrotron radiation - rollover between radio and x-ray spectra gives exponential cutoff of electron spectrum, and a limit to the energy of the associated cosmic rays - large contribution from this component modifies dynamics of thermal electr ...
... • high energy tail of nonthermal electrons yields x-ray synchrotron radiation - rollover between radio and x-ray spectra gives exponential cutoff of electron spectrum, and a limit to the energy of the associated cosmic rays - large contribution from this component modifies dynamics of thermal electr ...
Boron Abundances Across the" Li
... neault et al. 2004, which are specific to the Hyades. We use values of v sin i primarily from Mermilliod et al. (2009), but also from Paulson et al. (2003), Reiners & Schmidt (2003), and Kraft (1965) for the Hyades. We adopt [Fe/H] = 0.13, as discussed in the introduction. In Table 3 we list the val ...
... neault et al. 2004, which are specific to the Hyades. We use values of v sin i primarily from Mermilliod et al. (2009), but also from Paulson et al. (2003), Reiners & Schmidt (2003), and Kraft (1965) for the Hyades. We adopt [Fe/H] = 0.13, as discussed in the introduction. In Table 3 we list the val ...
On the possibility of a helium white dwarf donor in the presumed
... mere presence) of these bursts and the suggested hydrogen or helium depletion in the donor stars. The bursts detected from these systems last between 10 and a few hundred seconds, suggesting a high hydrogen and helium content in the flash fuel. The question is: where does the hydrogen and helium com ...
... mere presence) of these bursts and the suggested hydrogen or helium depletion in the donor stars. The bursts detected from these systems last between 10 and a few hundred seconds, suggesting a high hydrogen and helium content in the flash fuel. The question is: where does the hydrogen and helium com ...
Invited Review The Beginning and Evolution of the Universe
... they suggested that it would be useful to consider a nonequilibrium process. Gamow (1946), building on his earlier work, makes the crucial point that in the Big Bang Model “the conditions necessary for rapid nuclear reactions were existing only for a very short time, so that it may be quite dangerou ...
... they suggested that it would be useful to consider a nonequilibrium process. Gamow (1946), building on his earlier work, makes the crucial point that in the Big Bang Model “the conditions necessary for rapid nuclear reactions were existing only for a very short time, so that it may be quite dangerou ...
THREE Li-RICH K GIANTS - Indian Institute of Astrophysics
... for line formation. For the super–Li-rich giants HD 19745 and IRAS 135394151, non-LTE corrections indicate a correction of 0.1 dex upward for the 6103 8 line and 0.2 dex downward for the 6707 8 line (Carlsson et al. 1994). For the less Li-rich stars IRAS 123276523 and IRAS 175963952, the non-LTE ...
... for line formation. For the super–Li-rich giants HD 19745 and IRAS 135394151, non-LTE corrections indicate a correction of 0.1 dex upward for the 6103 8 line and 0.2 dex downward for the 6707 8 line (Carlsson et al. 1994). For the less Li-rich stars IRAS 123276523 and IRAS 175963952, the non-LTE ...
ASTRONOMY AND ASTROPHYSICS Elemental abundances of
... flux calibrations the standard star LTT 9491 was observed with the same grisms. The 2 D longslit spectra were reduced and analysed using standard MIDAS software. First, the spectra were bias subtracted and flatfield corrected. Cosmic-ray events on the CCD images were removed manually by comparing th ...
... flux calibrations the standard star LTT 9491 was observed with the same grisms. The 2 D longslit spectra were reduced and analysed using standard MIDAS software. First, the spectra were bias subtracted and flatfield corrected. Cosmic-ray events on the CCD images were removed manually by comparing th ...
The chemical composition of IK Pegasi
... The Kurucz & Pevtremann (1975) and Kurucz (1988, private communication) line lists were used to identify absorption lines which appeared to be unblended (i.e. more than 95 per cent in the absorption feature was due to only one line). This process was complicated by the moderately high value of v sin ...
... The Kurucz & Pevtremann (1975) and Kurucz (1988, private communication) line lists were used to identify absorption lines which appeared to be unblended (i.e. more than 95 per cent in the absorption feature was due to only one line). This process was complicated by the moderately high value of v sin ...
1 A CLOSED NON-COLLAPSING 3-D UNIVERSE PREDICTING A
... “essence” of radiation and matter has not yet been accounted for but a reproducing dark mass has been introduced as x-type 4-D pk. There is no such entity in current theory so a new scaling law must be introduced for it in the expansion model and that scaling law must make dark mass become the prese ...
... “essence” of radiation and matter has not yet been accounted for but a reproducing dark mass has been introduced as x-type 4-D pk. There is no such entity in current theory so a new scaling law must be introduced for it in the expansion model and that scaling law must make dark mass become the prese ...
Kalam Cosmological Argument
... Similarly, the late J. L. Mackie, in refuting the kalām cosmological argument, turns his main guns on this first step: “There is a priori no good reason why a sheer origination of things, not determined by anything, should be unacceptable, whereas the existence of a god [sic] with the power to create ...
... Similarly, the late J. L. Mackie, in refuting the kalām cosmological argument, turns his main guns on this first step: “There is a priori no good reason why a sheer origination of things, not determined by anything, should be unacceptable, whereas the existence of a god [sic] with the power to create ...
Tracing the evolution of NGC 6397 through the chemical
... products. The remaining gas is dispersed by core-collapse supernovae of the second generation and star formation ceases. The present-day cluster is dominated by the second generation, with a smaller fraction, approximately 30%, being left of the primordial population. Critical factors determining th ...
... products. The remaining gas is dispersed by core-collapse supernovae of the second generation and star formation ceases. The present-day cluster is dominated by the second generation, with a smaller fraction, approximately 30%, being left of the primordial population. Critical factors determining th ...
exploring anticorrelations and light element variations
... northern GCs, something that makes it possible to analyze these clusters in a homogeneous way, which has not been done before for these objects. The study of GCs with APOGEE plays an important role not just because it has access to many northern GCs. Its highresolution near-IR spectra allow the simu ...
... northern GCs, something that makes it possible to analyze these clusters in a homogeneous way, which has not been done before for these objects. The study of GCs with APOGEE plays an important role not just because it has access to many northern GCs. Its highresolution near-IR spectra allow the simu ...
Chapter 4 On the possibility of a helium white dwarf donor in the
... layers that were lost being outside the Roche lobe. Juett et al. and Nelemans et al. suggest that spallation of accreted elements may be important (e.g., Bildsten, Salpeter & Wasserman 1992). However, it is not trivial to invoke spallation. Spallation requires hydrogen nuclei (protons) to bombard th ...
... layers that were lost being outside the Roche lobe. Juett et al. and Nelemans et al. suggest that spallation of accreted elements may be important (e.g., Bildsten, Salpeter & Wasserman 1992). However, it is not trivial to invoke spallation. Spallation requires hydrogen nuclei (protons) to bombard th ...
mass transfer in close, rapidly accreting protobinaries
... binary D33 J013346.2+304439.9 in M33 is 0.22 AU (Bonanos et al. 2006). Harries et al. (2003) and Hilditch et al. (2005) report a sample of 50 OB star eclipsing binaries with periods of 5 days or less taken from the Optical Gravitational Lens Experiment survey (OGLE; Udalski et al. 1998) of the SMC. ...
... binary D33 J013346.2+304439.9 in M33 is 0.22 AU (Bonanos et al. 2006). Harries et al. (2003) and Hilditch et al. (2005) report a sample of 50 OB star eclipsing binaries with periods of 5 days or less taken from the Optical Gravitational Lens Experiment survey (OGLE; Udalski et al. 1998) of the SMC. ...
astro-ph/0210527 PDF
... which were dynamically nearby to that state to be in the same coarse grained “bin”, and, and by similarly making other coarse grained bins from other more dynamically distant states. From that particular coarse-graining, the box of gas illustrated in Figure 1 would not exhibit an arrow of time. The ...
... which were dynamically nearby to that state to be in the same coarse grained “bin”, and, and by similarly making other coarse grained bins from other more dynamically distant states. From that particular coarse-graining, the box of gas illustrated in Figure 1 would not exhibit an arrow of time. The ...
The CN/C15 N isotopic ratio towards dark clouds
... in the dense ISM, the determination of the bulk 14 N/ 15N is indirect and relies on the observation of minor N-bearing molecules. To which extent the abundance ratio of two isotopologues of a given molecule is representative of the elemental isotopic ratio depends on so-called fractionation processe ...
... in the dense ISM, the determination of the bulk 14 N/ 15N is indirect and relies on the observation of minor N-bearing molecules. To which extent the abundance ratio of two isotopologues of a given molecule is representative of the elemental isotopic ratio depends on so-called fractionation processe ...
Detection of Elements at All Three r-process Peaks in the Metal
... residuals. This method of computing these residuals assumes that the r-process produced some fraction of all heavy isotopes in the S.S. except those attributed to s-process nucleosynthesis or inaccessible to the r-process (e.g., Seeger et al. 1965; Cameron 1982; Käppeler et al. 1989). Light n-captu ...
... residuals. This method of computing these residuals assumes that the r-process produced some fraction of all heavy isotopes in the S.S. except those attributed to s-process nucleosynthesis or inaccessible to the r-process (e.g., Seeger et al. 1965; Cameron 1982; Käppeler et al. 1989). Light n-captu ...
astro-ph/0301519 PDF
... upper limits in those stars where particular elements are not detected. We find that the presence or absence of heavy elements in the hot DA white dwarfs largely reflects what would be expected if radiative levitation is the supporting mechanism, although the measured abundances do not match the pre ...
... upper limits in those stars where particular elements are not detected. We find that the presence or absence of heavy elements in the hot DA white dwarfs largely reflects what would be expected if radiative levitation is the supporting mechanism, although the measured abundances do not match the pre ...
Doppler imaging of AB Doradus using the Li I 6708 line
... The presence of blends potentially affects Li abundance measurements in two ways. The continuum level at the blue wing of the Li line profile is hard to determine accurately (see Fig. 2), due to a strong Fel line at 6705.12 A. Another Fel line at 6710.31 A. blends with the red wing of the rotational ...
... The presence of blends potentially affects Li abundance measurements in two ways. The continuum level at the blue wing of the Li line profile is hard to determine accurately (see Fig. 2), due to a strong Fel line at 6705.12 A. Another Fel line at 6710.31 A. blends with the red wing of the rotational ...
cosmic-ray neon, wolf-rayet stars, and the superbubble origin of
... that the presolar nebula could have been enriched by ejecta from nearby supernovae (SNe) in the association, and they cite meteoritic evidence of the extinct radioactive isotopes 26Al and 107Pd, which indicates that the presolar nebula must have been enriched by ejecta from at least one SN within 1 ...
... that the presolar nebula could have been enriched by ejecta from nearby supernovae (SNe) in the association, and they cite meteoritic evidence of the extinct radioactive isotopes 26Al and 107Pd, which indicates that the presolar nebula must have been enriched by ejecta from at least one SN within 1 ...
Richard Congdon. pdf
... temperature of 2.58 x 1010 K. There are 109 times more photons than protons or neutrons (nucleons) which mean there are a large number of photons, in the high energy tail of the photon energy distribution, with energies above 2.225 MeV available to reverse the process. The large photon-nucleon densi ...
... temperature of 2.58 x 1010 K. There are 109 times more photons than protons or neutrons (nucleons) which mean there are a large number of photons, in the high energy tail of the photon energy distribution, with energies above 2.225 MeV available to reverse the process. The large photon-nucleon densi ...
Thermal history of the universe with dark energy
... Near the end of the twentieth century, the astronomical observations on the redshift of supernovae [5, 6] showed that the universe was expanding at an accelerated rate, which justified the introduction of an entity with negative pressure to account for it, the dark energy. This revived the cosmologi ...
... Near the end of the twentieth century, the astronomical observations on the redshift of supernovae [5, 6] showed that the universe was expanding at an accelerated rate, which justified the introduction of an entity with negative pressure to account for it, the dark energy. This revived the cosmologi ...
f) Organizing the Elements Metals Nonmetals and
... carbon are illustrated in Figure 3. Each carbon atom has 6 protons, but you can see that the number of neutrons is 6, 7, or 8. An isotope is identified by its mass number, which is the sum of the protons and neutrons in the nucleus of an atom. The most common isotope of carbon has a mass number of 1 ...
... carbon are illustrated in Figure 3. Each carbon atom has 6 protons, but you can see that the number of neutrons is 6, 7, or 8. An isotope is identified by its mass number, which is the sum of the protons and neutrons in the nucleus of an atom. The most common isotope of carbon has a mass number of 1 ...
C, N, O abundances and carbon isotope ratios in evolved stars of
... −0.20±0.01, respectively. This means that the ratios of [C/Fe] in investigated stars of these clusters lie below the values obtained for dwarf stars of the Galactic disk, which are solar. Shi et al. (2002) performed an abundance analysis of carbon for a sample of 90 F- and G-type main-sequence disk ...
... −0.20±0.01, respectively. This means that the ratios of [C/Fe] in investigated stars of these clusters lie below the values obtained for dwarf stars of the Galactic disk, which are solar. Shi et al. (2002) performed an abundance analysis of carbon for a sample of 90 F- and G-type main-sequence disk ...
