2 The Birth of the Solar System: Some Unconventional Ideas
... Nevertheless, the Jeans model had some difficulties of its own. On the face of it, this model provided no reason why the orbital plane of the planets should be close to the equatorial plane of the Sun. Nor does it explain why the planets should orbit the Sun in the same direction as the latter’s rot ...
... Nevertheless, the Jeans model had some difficulties of its own. On the face of it, this model provided no reason why the orbital plane of the planets should be close to the equatorial plane of the Sun. Nor does it explain why the planets should orbit the Sun in the same direction as the latter’s rot ...
Ultra faint dwarfs: probing early cosmic star formation
... lower redshifts. Their smaller baryonic content is the result of shock-heating of the infalling gas during major merging events (Cox et al. 2004) which stops accretion. Finally, gas-poor systems formed by merging of recently virialized, Mh > Msf progenitors. Since most of the diffuse gas is still ac ...
... lower redshifts. Their smaller baryonic content is the result of shock-heating of the infalling gas during major merging events (Cox et al. 2004) which stops accretion. Finally, gas-poor systems formed by merging of recently virialized, Mh > Msf progenitors. Since most of the diffuse gas is still ac ...
Protecting planets from their stars
... the stellar wind velocity profile vary through the stellar cycle. One important unknown parameter that is needed in all models of stellar winds is the density at the base of the corona. Unfortunately, without a good estimate of this value, the stellar mass-loss rates, one of the fundamental properti ...
... the stellar wind velocity profile vary through the stellar cycle. One important unknown parameter that is needed in all models of stellar winds is the density at the base of the corona. Unfortunately, without a good estimate of this value, the stellar mass-loss rates, one of the fundamental properti ...
The potential of the variable DA white dwarf G117–B15A as
... when axion losses are taken into account. AGB stars are supposed to be the progenitors of white dwarfs and, therefore, white dwarfs are as well excellent candidates to test the existence of several weakly interacting massive particles. This was recognized early by several authors (see, for instance ...
... when axion losses are taken into account. AGB stars are supposed to be the progenitors of white dwarfs and, therefore, white dwarfs are as well excellent candidates to test the existence of several weakly interacting massive particles. This was recognized early by several authors (see, for instance ...
X-ray Sources in Nearby Galaxies Q. Daniel Wang University of Massachusetts
... • Feeding of AGNs • Evolution of HMXBs and LMXBs (talk by Andreas Zezas). • Discrete source populations such as SNe, SNRs, YSOs. • Effects of AGN energy injection, accretion from the IGM, clustering environment on diffuse hot plasma. • Diffuse hard X-rays: e.g., reflection, inverse Compton scat ...
... • Feeding of AGNs • Evolution of HMXBs and LMXBs (talk by Andreas Zezas). • Discrete source populations such as SNe, SNRs, YSOs. • Effects of AGN energy injection, accretion from the IGM, clustering environment on diffuse hot plasma. • Diffuse hard X-rays: e.g., reflection, inverse Compton scat ...
Galaxy Evolution in the SDSS Low
... runs: asinh mag flux average standard mag Average of 10 runs per object over factor of 3 improvement in S/N: e.g., at spectroscopic sample limit rP=19.5, median Petrosian mag error is 0.07 mag for an individual run (measured from empirical run-to-run scatter), but only 0.02 mag for catalog c ...
... runs: asinh mag flux average standard mag Average of 10 runs per object over factor of 3 improvement in S/N: e.g., at spectroscopic sample limit rP=19.5, median Petrosian mag error is 0.07 mag for an individual run (measured from empirical run-to-run scatter), but only 0.02 mag for catalog c ...
The Norman Lockyer plate archive collection
... > would be relevant for discussion in the seminar? No, nothing that cannot be divined from studying the observing note-books (which I believe you also have?). It would be useful, for instance, to get a ball-park figure for how many plates there are in that collection, and to show (if you can) a slid ...
... > would be relevant for discussion in the seminar? No, nothing that cannot be divined from studying the observing note-books (which I believe you also have?). It would be useful, for instance, to get a ball-park figure for how many plates there are in that collection, and to show (if you can) a slid ...
the mass of the black hole in cygnus x-1
... M > 3.6 M for D > 1.4 kpc. Based on dynamical modeling, Gies & Bolton (1986) found M > 7 M and a probable mass of Mopt = 16 M for the companion star, and Ninkov et al. (1987) found M = 10 ± 1 M (by assuming Mopt = 20 M ). However, these mass estimates, and all such estimates that have been made ...
... M > 3.6 M for D > 1.4 kpc. Based on dynamical modeling, Gies & Bolton (1986) found M > 7 M and a probable mass of Mopt = 16 M for the companion star, and Ninkov et al. (1987) found M = 10 ± 1 M (by assuming Mopt = 20 M ). However, these mass estimates, and all such estimates that have been made ...
Document
... Note: P- relations of the type P=K are called polytropic equations of state. We saw that this is exact for degenerate matter (e.g., inside a white dwarf ) and a good approximation for some normal stars. Now back to the fate of the evolving stars: During the contraction of a star, nuclear reacti ...
... Note: P- relations of the type P=K are called polytropic equations of state. We saw that this is exact for degenerate matter (e.g., inside a white dwarf ) and a good approximation for some normal stars. Now back to the fate of the evolving stars: During the contraction of a star, nuclear reacti ...
natural science and technology
... in other places. The atmosphere is thin. The average temperature is - 55° C. Mars has two moons. ...
... in other places. The atmosphere is thin. The average temperature is - 55° C. Mars has two moons. ...
106_1.pdf
... velocity dispersion of the suprathermal He and O ions (78 and 43 events, resp.) and estimate the onset time of the solar event and set limits on the propagation length along the connecting magnetic field line. ...
... velocity dispersion of the suprathermal He and O ions (78 and 43 events, resp.) and estimate the onset time of the solar event and set limits on the propagation length along the connecting magnetic field line. ...
The First Stars in the Universe
... Abraham Loeb of Harvard, one of us (Bromm) devised theoretical models of such stars with masses between 100 and 1,000 solar masses. The models showed that the stars had surface temperatures of about 100,000 kelvins—about 17 times higher than the sun’s surface temperature. Therefore, the first starli ...
... Abraham Loeb of Harvard, one of us (Bromm) devised theoretical models of such stars with masses between 100 and 1,000 solar masses. The models showed that the stars had surface temperatures of about 100,000 kelvins—about 17 times higher than the sun’s surface temperature. Therefore, the first starli ...
Winds from clusters with non-uniform stellar distribution
... We present analytic and numerical models of the `cluster wind' resulting from the multiple interactions of the winds ejected by the stars of a dense cluster of massive stars. We consider the case in which the distribution of stars (i.e., the number of stars per unit volume) within the cluster is sph ...
... We present analytic and numerical models of the `cluster wind' resulting from the multiple interactions of the winds ejected by the stars of a dense cluster of massive stars. We consider the case in which the distribution of stars (i.e., the number of stars per unit volume) within the cluster is sph ...
Nuclear structure and excitations by large
... Level density by large-scale shell model calc. Stochastic estimation for density of states ...
... Level density by large-scale shell model calc. Stochastic estimation for density of states ...
ASTR 31: Descriptive Astronomy
... 61Co has too many neutrons to be stable and radioactively decays: 61Co → 61Ni + e- + <e> + This continues, making the rest of the elements through bismuth-209 (83 protons + 126 neutrons), including such famous elements as copper, silver, lead, gold, etc. Rapid neutron capture (r-process): ...
... 61Co has too many neutrons to be stable and radioactively decays: 61Co → 61Ni + e- + <e> + This continues, making the rest of the elements through bismuth-209 (83 protons + 126 neutrons), including such famous elements as copper, silver, lead, gold, etc. Rapid neutron capture (r-process): ...
– 1 – 1. Discrete Spectral Lines – DRAFT, INCOMPLETE
... Macroturbulence arises from large scale motions such as convection or rotation. (vrot for the Sun is about 1.9 km/sec.) In this case the local value of the line absorption α(ν) and of the predicted I(ν) is unaffected, but the velocity shifts this entire profile in frequency across the disk of the st ...
... Macroturbulence arises from large scale motions such as convection or rotation. (vrot for the Sun is about 1.9 km/sec.) In this case the local value of the line absorption α(ν) and of the predicted I(ν) is unaffected, but the velocity shifts this entire profile in frequency across the disk of the st ...
Evolution of supermassive stars as a pathway to black hole formation
... star with increasing specific entropy as a function of time. Since the Kelvin-Helmholtz timescale is longer than the age of the star for early times and high infall rates, much of this this entropy stratification is preserved over the life of the star. We therefore conclude that supermassive stars a ...
... star with increasing specific entropy as a function of time. Since the Kelvin-Helmholtz timescale is longer than the age of the star for early times and high infall rates, much of this this entropy stratification is preserved over the life of the star. We therefore conclude that supermassive stars a ...