Implications for dwarf spheroidal mass content from interloper removal
... Another important consideration is that the central regions of clusters are not tidally influenced by their surroundings, both because of their mass dominance and the time scales involved. Similarly, the majority of spirals evolve in the field, where galaxy-galaxy interaction are relatively rare. At ...
... Another important consideration is that the central regions of clusters are not tidally influenced by their surroundings, both because of their mass dominance and the time scales involved. Similarly, the majority of spirals evolve in the field, where galaxy-galaxy interaction are relatively rare. At ...
Notes for Class 14, April 21
... Moti Nissani, What Is Science? • Difficult or impossible to give a dictionarytype definition for science • (DB) Working scientists rarely think about the history or philosophy of science • Start with philosophy of Thales – free ...
... Moti Nissani, What Is Science? • Difficult or impossible to give a dictionarytype definition for science • (DB) Working scientists rarely think about the history or philosophy of science • Start with philosophy of Thales – free ...
Luminosity
... – Rising of hot plasma carries energy through the convection zone to photosphere. ...
... – Rising of hot plasma carries energy through the convection zone to photosphere. ...
Cosmology with objects from the Hamburg Quasar Surveys
... difference between the two images. In the meantime (Poindexter et al., 2007) image A being distinctly bluer than B, the time delay has been determined as TD = 152 d, and the lens galaxy at z = 0.73 was discovered by Courbin et al. (1998). HE 1104-1805 is a gravitational (macro)lens with strong diffe ...
... difference between the two images. In the meantime (Poindexter et al., 2007) image A being distinctly bluer than B, the time delay has been determined as TD = 152 d, and the lens galaxy at z = 0.73 was discovered by Courbin et al. (1998). HE 1104-1805 is a gravitational (macro)lens with strong diffe ...
Stellar evolution models for Z = 0.0001 to 0.03
... 1993, Claret 1995), we do not parametrize the overshooting length lov in units of the pressure scaleheight HP (which we call the ‘HP prescription’). Instead, we base our treatment on the stability criterion itself, the ‘= prescription’, by incorporating the condition that mixing occurs in a region w ...
... 1993, Claret 1995), we do not parametrize the overshooting length lov in units of the pressure scaleheight HP (which we call the ‘HP prescription’). Instead, we base our treatment on the stability criterion itself, the ‘= prescription’, by incorporating the condition that mixing occurs in a region w ...
Stellar evolution models for Z = 0.0001 to 0.03
... 1993, Claret 1995), we do not parametrize the overshooting length lov in units of the pressure scaleheight HP (which we call the ‘HP prescription’). Instead, we base our treatment on the stability criterion itself, the ‘= prescription’, by incorporating the condition that mixing occurs in a region w ...
... 1993, Claret 1995), we do not parametrize the overshooting length lov in units of the pressure scaleheight HP (which we call the ‘HP prescription’). Instead, we base our treatment on the stability criterion itself, the ‘= prescription’, by incorporating the condition that mixing occurs in a region w ...
Article PDF - IOPscience
... By comparing the effective temperature, metallicity, and mean stellar density (ρ∗ ) of WASP-19 to theoretical stellar models, we determine its mass. The stellar density is dependent on the shape of the transit and largely independent of any assumptions or models (Seager & Mallén-Ornelas 2003). Thus ...
... By comparing the effective temperature, metallicity, and mean stellar density (ρ∗ ) of WASP-19 to theoretical stellar models, we determine its mass. The stellar density is dependent on the shape of the transit and largely independent of any assumptions or models (Seager & Mallén-Ornelas 2003). Thus ...
Stars, Galaxies, and the Universe
... is a star powers system of ten in to which writeone very star cannot large orgalaxies be very seen small at times numbers because in shorter other form. starmiddle blocks Spiral appear to have a the bulge in the the andlight. arms that spiral outward, like pinwheels. Open clusters havelook a loose, ...
... is a star powers system of ten in to which writeone very star cannot large orgalaxies be very seen small at times numbers because in shorter other form. starmiddle blocks Spiral appear to have a the bulge in the the andlight. arms that spiral outward, like pinwheels. Open clusters havelook a loose, ...
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 ...
ppt - IASF Milano
... •There are very few constraints on groups scale (1013 ≤ M ≤ 1014 Msun) , where numerical predictions are more accurate because a large number of halo can be simulated. ...
... •There are very few constraints on groups scale (1013 ≤ M ≤ 1014 Msun) , where numerical predictions are more accurate because a large number of halo can be simulated. ...
The quest for cradles of life: using the fundamental metallicity
... growth of complex life which yields a total affected volume of 43 π(Q pc)3 . Type II SN explode when the core mass exceeds the Chandrasekhar mass limit of 1.44 solar masses producing about 1053 erg/s of energy, 90% of which is radiated away as cosmic radiation (Shklovskii 1960; Woosley & Janka 2005) ...
... growth of complex life which yields a total affected volume of 43 π(Q pc)3 . Type II SN explode when the core mass exceeds the Chandrasekhar mass limit of 1.44 solar masses producing about 1053 erg/s of energy, 90% of which is radiated away as cosmic radiation (Shklovskii 1960; Woosley & Janka 2005) ...
ESO telescopes
... temperatures between 2,000 and 1,500 K. Therefore, IRAS 13481-6124 is following the size-luminosity relation22, which is well established for low- to intermediate mass ...
... temperatures between 2,000 and 1,500 K. Therefore, IRAS 13481-6124 is following the size-luminosity relation22, which is well established for low- to intermediate mass ...
Potassium abundances in nearby metal-poor stars
... On the observational side, the spectroscopic determination of potassium abundances is difficult. Only the resonance doublet (K 7665 and 7699 Å) is available for abundance analyses of metal-poor stars, however, K resonance lines are often blended with very strong telluric O2 lines. There have been ...
... On the observational side, the spectroscopic determination of potassium abundances is difficult. Only the resonance doublet (K 7665 and 7699 Å) is available for abundance analyses of metal-poor stars, however, K resonance lines are often blended with very strong telluric O2 lines. There have been ...
17.1 Introduction
... of convection, which then prevents the helium ionization zone from driving the pulsation. For hotter temperatures, the helium ionization zone is located too far out in the atmosphere for significant pulsations to occur. There are complications, of course. Stars spend only a short fraction of their l ...
... of convection, which then prevents the helium ionization zone from driving the pulsation. For hotter temperatures, the helium ionization zone is located too far out in the atmosphere for significant pulsations to occur. There are complications, of course. Stars spend only a short fraction of their l ...
Entropy Production of Stars
... variational principles proves to be important both for the foundation of nonequilibrium physics and for calculations: from heat-conduction problems to the solution of the Boltzmann equation [1–4]. It should be noted that the quantity of entropy production is convenient from the standpoint of theory ...
... variational principles proves to be important both for the foundation of nonequilibrium physics and for calculations: from heat-conduction problems to the solution of the Boltzmann equation [1–4]. It should be noted that the quantity of entropy production is convenient from the standpoint of theory ...
![arXiv:1606.05438v1 [astro-ph.SR] 17 Jun 2016](http://s1.studyres.com/store/data/013048193_1-92364881cbcc0fdb7f47e7990acc1537-300x300.png)
arXiv:1606.05438v1 [astro-ph.SR] 17 Jun 2016
... systems. The material transferred onto the white dwarf piles up under degenerate conditions, driving a thermonuclear runaway. In those outbursts, about 10−7 − 10−3 M⊙ , enriched in CNO and, sometimes, other intermediate-mass elements (e.g., Ne, Na, Mg, or Al, for ONe novae) are ejected into the inte ...
... systems. The material transferred onto the white dwarf piles up under degenerate conditions, driving a thermonuclear runaway. In those outbursts, about 10−7 − 10−3 M⊙ , enriched in CNO and, sometimes, other intermediate-mass elements (e.g., Ne, Na, Mg, or Al, for ONe novae) are ejected into the inte ...
SUMMARY OF KEY CONCEPTS: GALAXIES AND COSMOLOGY
... and gas. Dark energy – unseen `substance’ that appears to be causing the rate of expansion of the Universe to be accelerating (the opposite of what gravity is expected to do). In addition to the evidence from spiral galaxy rotation curves, additional evidence for the existence of dark matter comes f ...
... and gas. Dark energy – unseen `substance’ that appears to be causing the rate of expansion of the Universe to be accelerating (the opposite of what gravity is expected to do). In addition to the evidence from spiral galaxy rotation curves, additional evidence for the existence of dark matter comes f ...
jordi_so
... Progress report on the determination of absolute magnitudes using Strömgren photometry. ...
... Progress report on the determination of absolute magnitudes using Strömgren photometry. ...
Light n-Capture Element Abundances in Metal
... D. Burris, E. Jones, and J. Lusk 1989). The conditions needed are also generated in the shell-burning phase of Asymptotic Giant Branch (AGB) low to intermediate mass stars (Busso et al. 1999). These stars have lifetimes measured in billions of years. This is significant because n-capture elements c ...
... D. Burris, E. Jones, and J. Lusk 1989). The conditions needed are also generated in the shell-burning phase of Asymptotic Giant Branch (AGB) low to intermediate mass stars (Busso et al. 1999). These stars have lifetimes measured in billions of years. This is significant because n-capture elements c ...
Basic Assumptions About Convection The calculation of convection
... • The blob maintains pressure balance with its surroundings. thus the time for a pressure wave to cross the blob is much shorter than the timescale for blob motion, lm /vs ¿ lm /v. • Acoustic waves, shocks, magnetic fields, rotation, are all negligible. • The temperatures and densities inside a blob ...
... • The blob maintains pressure balance with its surroundings. thus the time for a pressure wave to cross the blob is much shorter than the timescale for blob motion, lm /vs ¿ lm /v. • Acoustic waves, shocks, magnetic fields, rotation, are all negligible. • The temperatures and densities inside a blob ...
FIRST LIGHT IN THE UNIVERSE
... • Contribution of lower luminosity systems less clear (lensing: Lecture 7) • Spitzer’s IRAC can detect large numbers of z~5-6 galaxies and it seems many have high masses (one spectacularly so!) and signatures of mature stellar populations - implies earlier activity • Reconciling mature galaxies at z ...
... • Contribution of lower luminosity systems less clear (lensing: Lecture 7) • Spitzer’s IRAC can detect large numbers of z~5-6 galaxies and it seems many have high masses (one spectacularly so!) and signatures of mature stellar populations - implies earlier activity • Reconciling mature galaxies at z ...
Fossil Galaxies
... star formation. The first panel shows the thousands of dark-matter clumps that coexist with our galaxy. The second panel highlights in green those dark-matter clumps massive enough to obtain gas from the intergalactic medium and trigger star formation, eventually creating dwarf galaxies. The third p ...
... star formation. The first panel shows the thousands of dark-matter clumps that coexist with our galaxy. The second panel highlights in green those dark-matter clumps massive enough to obtain gas from the intergalactic medium and trigger star formation, eventually creating dwarf galaxies. The third p ...
Post-AGB stars in the Magellanic Clouds and neutron
... from the valley of β stability by more than two or three atomic mass numbers for each given element, and it still proceeds sequentially throughout each value of the proton number. Finally, because the PIE was only included in the postprocessing calculations, we cannot evaluate its feedback on the st ...
... from the valley of β stability by more than two or three atomic mass numbers for each given element, and it still proceeds sequentially throughout each value of the proton number. Finally, because the PIE was only included in the postprocessing calculations, we cannot evaluate its feedback on the st ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.