The End of the Dark Ages
... peaks in the HI distribution.) The ionization front slows when it encounter such overdensities because of their higher recombination rate. By redshift z = 15.5 several bubbles are close to overlap in the L20 run (see upper-right corner of the central panel) whereas in the S20 run the filling factor ...
... peaks in the HI distribution.) The ionization front slows when it encounter such overdensities because of their higher recombination rate. By redshift z = 15.5 several bubbles are close to overlap in the L20 run (see upper-right corner of the central panel) whereas in the S20 run the filling factor ...
The origin of magnetism on the upper main sequence
... might play an important role in the formation of massive stars has been propounded by Bonnell, Bate & Zinnecker (1998) and Bonnell & Bate (2002). Further, the idea that magnetic field generation by mergers might be implicated in the formation of a strongly magnetic class of white dwarfs has been put ...
... might play an important role in the formation of massive stars has been propounded by Bonnell, Bate & Zinnecker (1998) and Bonnell & Bate (2002). Further, the idea that magnetic field generation by mergers might be implicated in the formation of a strongly magnetic class of white dwarfs has been put ...
PoS(AASKA14)174 - Proceeding of science
... a constant rate of stars ageing and being replaced. What instead became apparent in the late 1990’s is that the rate at which stars are formed has varied dramatically with time. That rate has increased from a low level in the early Universe to a major peak at some 3 billion years of age, followed by ...
... a constant rate of stars ageing and being replaced. What instead became apparent in the late 1990’s is that the rate at which stars are formed has varied dramatically with time. That rate has increased from a low level in the early Universe to a major peak at some 3 billion years of age, followed by ...
Matter Cycle in the Interstellar Medium (ISM)
... ➙ obscuring matter rather than vacuum, blocking light from more distant stars.! ...
... ➙ obscuring matter rather than vacuum, blocking light from more distant stars.! ...
Stellar death - Department of Astronomy
... Cores of low-mass stars collapse after losing their envelopes Generate luminosity (Kelvin-Helmholtz mechanism) R = 0.01R⊙ ≈ REarth ! ...
... Cores of low-mass stars collapse after losing their envelopes Generate luminosity (Kelvin-Helmholtz mechanism) R = 0.01R⊙ ≈ REarth ! ...
Star Wreck
... Electrically Charged Solitons (SECS) [3]. In a neutron star, where all nucleons are electrically neutral, there is no difference between SENS and SECS. However, when we discuss the fate of the white dwarfs, we will have to make a distinction between the two types. When a neutron star is born in a su ...
... Electrically Charged Solitons (SECS) [3]. In a neutron star, where all nucleons are electrically neutral, there is no difference between SENS and SECS. However, when we discuss the fate of the white dwarfs, we will have to make a distinction between the two types. When a neutron star is born in a su ...
![Chapter 4 [PDF only] - Princeton University Press](http://s1.studyres.com/store/data/016931743_1-7c8ec22374457bf50a0a03f55488ddc7-300x300.png)
Chapter 4 [PDF only] - Princeton University Press
... the horizontal branch, and then evolves more slowly to the right along this branch, as seen in Fig. 4.1. Horizontal branch evolution last only about 1% of the main-sequence lifetime. Once the helium in the core has been exhausted, the core (now composed mainly of oxygen and carbon) contracts again, ...
... the horizontal branch, and then evolves more slowly to the right along this branch, as seen in Fig. 4.1. Horizontal branch evolution last only about 1% of the main-sequence lifetime. Once the helium in the core has been exhausted, the core (now composed mainly of oxygen and carbon) contracts again, ...
uncorrected page proofs
... In parallel to the experimental work of Shapley, Hubble and other astronomers, theoretical physics was making tremendous progress. In particular, Albert Einstein published his General Theory of Relativity in 1915, which provided a new way of understanding gravity. Until then, scientists had used Isa ...
... In parallel to the experimental work of Shapley, Hubble and other astronomers, theoretical physics was making tremendous progress. In particular, Albert Einstein published his General Theory of Relativity in 1915, which provided a new way of understanding gravity. Until then, scientists had used Isa ...
Physics of Stars and the Measurement Data: Part III
... not it, because will consider only electro-neutral cell, in which the charge of the nucleus exactly offset by the electronic charge, so the electric field on the cell border is equal to zero. ...
... not it, because will consider only electro-neutral cell, in which the charge of the nucleus exactly offset by the electronic charge, so the electric field on the cell border is equal to zero. ...
3D GR Hydrodynamic Simulations of Binary Neutron Star
... 1) Capture fluxes on coarse and fine grid AMR boundary 2) Integrate both until coarse and fine grid are aligned in time again 3) Restrict integrated coarse grid flux onto fine grid boundary 4) Difference between integrated coarse grid flux and fine grid flux is correction ...
... 1) Capture fluxes on coarse and fine grid AMR boundary 2) Integrate both until coarse and fine grid are aligned in time again 3) Restrict integrated coarse grid flux onto fine grid boundary 4) Difference between integrated coarse grid flux and fine grid flux is correction ...
the opportunities and challenges for astrometry in the 21st century
... to map the shape of the corrugations in real time and distorting a flexible transfer mirror to compensate for the atmospheric corrugations; however, it is a very costly approach. At a good observing site the correlation between the atmospheric shifts experienced by two stars separated by 4 arcminute ...
... to map the shape of the corrugations in real time and distorting a flexible transfer mirror to compensate for the atmospheric corrugations; however, it is a very costly approach. At a good observing site the correlation between the atmospheric shifts experienced by two stars separated by 4 arcminute ...
Chapter 9 Post-main sequence evolution through helium burning
... intermediate-mass stars ignite helium stably in a non-degenerate core, but after central He burning they develop a degenerate carbon-oxygen core. They have masses between MHeF and Mup ≈ 8 M⊙ . Both low-mass and intermediate-mass stars shed their envelopes by a strong stellar wind at the end of their ...
... intermediate-mass stars ignite helium stably in a non-degenerate core, but after central He burning they develop a degenerate carbon-oxygen core. They have masses between MHeF and Mup ≈ 8 M⊙ . Both low-mass and intermediate-mass stars shed their envelopes by a strong stellar wind at the end of their ...
UV habitable zones around M stars - IAFE
... To date (June 2007) nine dM stars were found hosting planetary systems. Three of them were observed by IUE: HIP 74995 (M3V), HIP 109388 (M3.5V) and HIP 113020 (M4V). In Table 1 we list some physical parameters of the host stars and their corresponding planets. The flare stars AD Leo (M3.5Ve) and EV ...
... To date (June 2007) nine dM stars were found hosting planetary systems. Three of them were observed by IUE: HIP 74995 (M3V), HIP 109388 (M3.5V) and HIP 113020 (M4V). In Table 1 we list some physical parameters of the host stars and their corresponding planets. The flare stars AD Leo (M3.5Ve) and EV ...
Formation of spiral and elliptical galaxies in a CDM cosmogony
... nearly solar composition. The spiral is embedded in a triaxial halo of dark matter. The disk possesses an exponential brightness pro le, while halo and bulge follow the de Vaucouleurs law. The disk is rotationally supported with a at rotation curve. The attening of the triaxial bulge is probably d ...
... nearly solar composition. The spiral is embedded in a triaxial halo of dark matter. The disk possesses an exponential brightness pro le, while halo and bulge follow the de Vaucouleurs law. The disk is rotationally supported with a at rotation curve. The attening of the triaxial bulge is probably d ...
Pair instability supernovae: Evolution, explosion, nucleosynthesis
... end of their lives, which comprise about two-third of all supernovae. These events produce neutron stars or black holes as compact remnants. It has since long been predicted that very massive star, i.e., stars above 140 solar masses, undergo a dynamical collapse due to electron-positron pair creatio ...
... end of their lives, which comprise about two-third of all supernovae. These events produce neutron stars or black holes as compact remnants. It has since long been predicted that very massive star, i.e., stars above 140 solar masses, undergo a dynamical collapse due to electron-positron pair creatio ...
A Detailed Spectroscopic and Photometric Analysis of DQ White
... et al. 1986), the C2 Swan bands should be easily detectable in much cooler objects, even for the small carbon abundances expected from evolutionary calculations (see § 2 below). On the basis of the results shown in Figure 1, BRL and BLR suggested that the absence of DQ stars was not a selection effe ...
... et al. 1986), the C2 Swan bands should be easily detectable in much cooler objects, even for the small carbon abundances expected from evolutionary calculations (see § 2 below). On the basis of the results shown in Figure 1, BRL and BLR suggested that the absence of DQ stars was not a selection effe ...
White Paper on Nuclear Astrophysics
... This white paper should also inform the nuclear physics community and funding agencies about the scientific directions and priorities of the field with the goal of providing input for the 2014 Long Range Plan. The answer of many questions in nuclear astrophysics can be found in the physics of nuclea ...
... This white paper should also inform the nuclear physics community and funding agencies about the scientific directions and priorities of the field with the goal of providing input for the 2014 Long Range Plan. The answer of many questions in nuclear astrophysics can be found in the physics of nuclea ...
Document
... >1600 stars down to 19th magnitude, yielding a detection of variability in about 8% of the field stars. Have measured eclipsing binary periods down to tenths or hundredths of a second. Variation in orbital parameters gives information on perturbations in the system. Expect detections or stringent up ...
... >1600 stars down to 19th magnitude, yielding a detection of variability in about 8% of the field stars. Have measured eclipsing binary periods down to tenths or hundredths of a second. Variation in orbital parameters gives information on perturbations in the system. Expect detections or stringent up ...
Toward $ ab\, initio $ extremely metal poor stars
... around the density maximum with an ‘active’ (gravitating) Pop III star particle. This replacement capped the gas density around the maximum, where the star particle was inserted, at a ceiling computed consistent with mass conservation. We ray-traced ionizing radiation from the star particle to compu ...
... around the density maximum with an ‘active’ (gravitating) Pop III star particle. This replacement capped the gas density around the maximum, where the star particle was inserted, at a ceiling computed consistent with mass conservation. We ray-traced ionizing radiation from the star particle to compu ...
Massive star evolution: luminous blue variables as unexpected
... Key words. stars: evolution – supernovae: general – stars: massive – stars: winds, outflows – stars: fundamental parameters – stars: rotation ...
... Key words. stars: evolution – supernovae: general – stars: massive – stars: winds, outflows – stars: fundamental parameters – stars: rotation ...
![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 ...
Life and Death of Stars
... Enough energy is released to fuse C into elements heavier than C. "Progenitor IA supernova" by NASA, ESA and A. Feild (STScI); vectorisation by chris 論 - http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/34/image/d/. Licensed under CC BY 3.0 via Wikimedia Commons - http://commons ...
... Enough energy is released to fuse C into elements heavier than C. "Progenitor IA supernova" by NASA, ESA and A. Feild (STScI); vectorisation by chris 論 - http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/34/image/d/. Licensed under CC BY 3.0 via Wikimedia Commons - http://commons ...
Cosmology Notes - U of L Class Index
... Steady State: Hoyle, Bondi, Gold defended the view that the universe continues steadily expanding, with new matter coming into existence in the resulting space, filling it with new galaxies over time. Their universe is eternal, with no beginning and no end—an echo of Aristotle’s cosmology. Evidence: ...
... Steady State: Hoyle, Bondi, Gold defended the view that the universe continues steadily expanding, with new matter coming into existence in the resulting space, filling it with new galaxies over time. Their universe is eternal, with no beginning and no end—an echo of Aristotle’s cosmology. Evidence: ...
Sub-luminous type Ia supernovae from the mergers of equal
... diversity. Interestingly, a recent analysis of the spectral evolution of SN 2005bl10, which is representative of the 1991bg-like SNe Ia, showed that both iron group elements and silicon are present over a wide range of radii extending as close to the centre of the ejecta as is accessible observation ...
... diversity. Interestingly, a recent analysis of the spectral evolution of SN 2005bl10, which is representative of the 1991bg-like SNe Ia, showed that both iron group elements and silicon are present over a wide range of radii extending as close to the centre of the ejecta as is accessible observation ...
here - SDSU Astronomy Department and Mount Laguna Observatory
... In many cases, this is because they are pulsating. The radius and temperature changes over the cycle, giving rise to brightness variations. Image from Nick Strobel’s Astronomy Notes (http://www.astronomynotes.com) ...
... In many cases, this is because they are pulsating. The radius and temperature changes over the cycle, giving rise to brightness variations. Image from Nick Strobel’s Astronomy Notes (http://www.astronomynotes.com) ...
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen and helium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos.With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis, a process that continues today. Some of these elements, particularly those lighter than iron, continue to be delivered to the interstellar medium when low mass stars eject their outer envelope before they collapse to form white dwarfs. The remains of their ejected mass form the planetary nebulae observable throughout our galaxy.Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28). Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the R process) in the period of a few seconds during the explosion. The elements formed in supernovas include the heaviest elements known, such as the long-lived elements uranium and thorium.Cosmic ray spallation, caused when cosmic rays impact the interstellar medium and fragment larger atomic species, is a significant source of the lighter nuclei, particularly 3He, 9Be and 10,11B, that are not created by stellar nucleosynthesis.In addition to the fusion processes responsible for the growing abundances of elements in the universe, a few minor natural processes continue to produce very small numbers of new nuclides on Earth. These nuclides contribute little to their abundances, but may account for the presence of specific new nuclei. These nuclides are produced via radiogenesis (decay) of long-lived, heavy, primordial radionuclides such as uranium and thorium. Cosmic ray bombardment of elements on Earth also contribute to the presence of rare, short-lived atomic species called cosmogenic nuclides.