Transcendental syntax I: deterministic case
... proof is correct amounts at saying that the plugging of the vehicle — the upper part made of identity links — with such an ordeal normalises into a link of a specified form. The finite set of all ordeals is called a gabarit: the gabarit thus conveys the spirit, the sense of the formula we are provin ...
... proof is correct amounts at saying that the plugging of the vehicle — the upper part made of identity links — with such an ordeal normalises into a link of a specified form. The finite set of all ordeals is called a gabarit: the gabarit thus conveys the spirit, the sense of the formula we are provin ...
Radiation-driven Feedback to the ISM around AGNs
... for LA G N /LE = 0.01 and 0.1, respectively. For LA G N = 0.1LE , the net accretion rate is one order of magnitude smaller than the accretion rate required to maintain constant AGN luminosity; the AGN luminosity is assumed to be constant during the calculations provided that the energy conversion effi ...
... for LA G N /LE = 0.01 and 0.1, respectively. For LA G N = 0.1LE , the net accretion rate is one order of magnitude smaller than the accretion rate required to maintain constant AGN luminosity; the AGN luminosity is assumed to be constant during the calculations provided that the energy conversion effi ...
Pop III binary population synthesis
... This uncertainty change event rate by a factor of several hundreds. We should reveal this uncertainty via comparison between result of population synthesis and observations such as GW and other observations and improve binary evolution theory ...
... This uncertainty change event rate by a factor of several hundreds. We should reveal this uncertainty via comparison between result of population synthesis and observations such as GW and other observations and improve binary evolution theory ...
CEA - The Sun
... loss of energy at the surface and allows the Sun to burn sustainably; contraction causes an increase in heating providing the energy to remain in balance from its gravitational capital. In reality, these two phenomena are linked: since the nuclear resources are limited, gravitational contraction of ...
... loss of energy at the surface and allows the Sun to burn sustainably; contraction causes an increase in heating providing the energy to remain in balance from its gravitational capital. In reality, these two phenomena are linked: since the nuclear resources are limited, gravitational contraction of ...
Star Formation: Chemistry as a Probe of Embedded Protostars
... (circles), early Class I (squares), and late Class I (triangles). ...
... (circles), early Class I (squares), and late Class I (triangles). ...
a fresh catch of massive binaries in the cygnus ob2 association
... We measured the radial velocity for each spectrum obtained at WIRO using Gaussian fits to the He i λ5876 line. Systemic velocities are, therefore, based solely on this line, by adopting a rest wavelength of 5875.69 Å measured in model stellar spectra with static atmospheres (TLUSTY; Lanz & Hubeny 20 ...
... We measured the radial velocity for each spectrum obtained at WIRO using Gaussian fits to the He i λ5876 line. Systemic velocities are, therefore, based solely on this line, by adopting a rest wavelength of 5875.69 Å measured in model stellar spectra with static atmospheres (TLUSTY; Lanz & Hubeny 20 ...
ellc: A fast, flexible light curve model for detached eclipsing binary
... spectrum of the incident radiation at each point on the star’s surface would require integration of the emergent spectrum over the visible surface of the companion accounting for the variation in limb darkening and gravity darkening with wavelength, and then iterating to account for the radiation re ...
... spectrum of the incident radiation at each point on the star’s surface would require integration of the emergent spectrum over the visible surface of the companion accounting for the variation in limb darkening and gravity darkening with wavelength, and then iterating to account for the radiation re ...
Cooling neutron star in the Cassiopeia A supernova remnant
... • Critical temperature profile should not be to narrow and CPF emission should not be strongly supressed (q>0.4) • Neutrino emission prior to onset of CPF should be 20-100 times weaker then the standard mUrca cooling rate ...
... • Critical temperature profile should not be to narrow and CPF emission should not be strongly supressed (q>0.4) • Neutrino emission prior to onset of CPF should be 20-100 times weaker then the standard mUrca cooling rate ...
Infrared Photometry of Red Supergiants in Young Clusters in the
... Previous IR studies within these clusters have been limited. A sample of the outlying RSGs from NGC 330, 2004 and 2100 were observed by McGregor & Hyland (1984). A similar sample was also taken by Carney et al. (1985) in NGC 330. These studies drew upon the derived temperatures and luminosities of t ...
... Previous IR studies within these clusters have been limited. A sample of the outlying RSGs from NGC 330, 2004 and 2100 were observed by McGregor & Hyland (1984). A similar sample was also taken by Carney et al. (1985) in NGC 330. These studies drew upon the derived temperatures and luminosities of t ...
GRB 021004: A Possible Shell Nebula around a Wolf
... spectrum, we concluded that radiation acceleration by bound-free transitions had to be most efficient in the early stages of the GRB [11, 12]. Figure 3 shows the predicted velocity profile for one set of initial conditions. Faster outflowing absorbers can be explained by nearby circumstellar materia ...
... spectrum, we concluded that radiation acceleration by bound-free transitions had to be most efficient in the early stages of the GRB [11, 12]. Figure 3 shows the predicted velocity profile for one set of initial conditions. Faster outflowing absorbers can be explained by nearby circumstellar materia ...
ASTROPHYSICAL PARAMETERS OF LS 2883 AND IMPLICATIONS FOR THE Y egueruela ,
... and absorption processes in these so-called gamma-ray binaries. Here we present high-resolution and high signalto-noise optical spectra of LS 2883, the Be star forming a gamma-ray binary with the young non-accreting pulsar PSR B1259–63, showing it to rotate faster and be significantly earlier and mo ...
... and absorption processes in these so-called gamma-ray binaries. Here we present high-resolution and high signalto-noise optical spectra of LS 2883, the Be star forming a gamma-ray binary with the young non-accreting pulsar PSR B1259–63, showing it to rotate faster and be significantly earlier and mo ...
The Formation of Massive Stars - Max-Planck
... counterpart in the GLIMPSE data. While this could also indicate a genuine HMSC, they found relatively high temperatures [~33 K from NH3(1,1) and (2,2)], an increasing N2H+(1–0) line width from the core edge to the core center, and so-called “green fuzzy” mid-infrared emission at the edge of the core ...
... counterpart in the GLIMPSE data. While this could also indicate a genuine HMSC, they found relatively high temperatures [~33 K from NH3(1,1) and (2,2)], an increasing N2H+(1–0) line width from the core edge to the core center, and so-called “green fuzzy” mid-infrared emission at the edge of the core ...
An exceptionally bright flare from SGR 1806–20 and the origins of
... dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR 1806–20, which was much more luminous than any previous transient event observed in our Galaxy. (In the first 0.2 s, the flare released as much energy as the Sun radiates in a quarter of a million yea ...
... dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR 1806–20, which was much more luminous than any previous transient event observed in our Galaxy. (In the first 0.2 s, the flare released as much energy as the Sun radiates in a quarter of a million yea ...
GALAXY FORMATION AND CLUSTER FORMATION Richard B
... disk, violent instability occurs when Q < 1; limited growth of spiral density perturbations occurs for 1 < Q < ^2 (Larson 1984); and stability occurs for Q > ^ 2 . Numerical simulations of disks containing gas (e.g. Sellwood and Carlberg 1984) show that, while dissipation tends to reduce Q and make ...
... disk, violent instability occurs when Q < 1; limited growth of spiral density perturbations occurs for 1 < Q < ^2 (Larson 1984); and stability occurs for Q > ^ 2 . Numerical simulations of disks containing gas (e.g. Sellwood and Carlberg 1984) show that, while dissipation tends to reduce Q and make ...
How plausible are the proposed formation scenarios of CEMP
... abundances currently available and includes 1944 MP stars with [Fe/H] < −1. Stars with higher iron abundances in the SAGA database do not show large enrichments in either barium or europium, and therefore we exclude them from our sample. We select the MP stars with observed abundances of barium and ...
... abundances currently available and includes 1944 MP stars with [Fe/H] < −1. Stars with higher iron abundances in the SAGA database do not show large enrichments in either barium or europium, and therefore we exclude them from our sample. We select the MP stars with observed abundances of barium and ...
Shock?heating of stellar envelopes: a possible common mechanism
... ∼10 M on the main sequence. Rather than focusing on specific models, like those potentially associated with failed SNe (Fryer et al. 2009), we parametrize the problem through a simple energy deposition, taking place with a given magnitude, over a given time and at a given depth in a set of pre-SN p ...
... ∼10 M on the main sequence. Rather than focusing on specific models, like those potentially associated with failed SNe (Fryer et al. 2009), we parametrize the problem through a simple energy deposition, taking place with a given magnitude, over a given time and at a given depth in a set of pre-SN p ...
The diameter of the CoRoT target HD 49933
... We use the state-of-the-art radiative hydrodynamical code (STAGGER CODE, Nordlund & Galsgaard2) to simulate the surface convection and stratification of HD 49933. In a local box, the code solves the full set of conservative hydrodynamical equations coupled to an accurate treatment of the radiative t ...
... We use the state-of-the-art radiative hydrodynamical code (STAGGER CODE, Nordlund & Galsgaard2) to simulate the surface convection and stratification of HD 49933. In a local box, the code solves the full set of conservative hydrodynamical equations coupled to an accurate treatment of the radiative t ...
Potential biosignatures in super
... with a biosphere. In this study, we therefore assume the same initial modern Earth atmospheric composition and biomass emissions for the simulated extra-solar planets. The final atmospheric composition for the star-planet-scenarios studied was then consistently calculated according to the coupled cl ...
... with a biosphere. In this study, we therefore assume the same initial modern Earth atmospheric composition and biomass emissions for the simulated extra-solar planets. The final atmospheric composition for the star-planet-scenarios studied was then consistently calculated according to the coupled cl ...
Life and Death of Stars
... Large Stars on the Main Sequence More mass → More gravitational energy → Higher core temperature → Faster fusion rate → Shorter time on the main sequence ...
... Large Stars on the Main Sequence More mass → More gravitational energy → Higher core temperature → Faster fusion rate → Shorter time on the main sequence ...
Document
... • The sun is not powered by cooling! • Nuclear fusion – We understand the physics of this very well indeed • We can create fusion reactions on Earth! • We can measure the sun’s energy output • We know the processes causing this • We know how much fuel the sun has ...
... • The sun is not powered by cooling! • Nuclear fusion – We understand the physics of this very well indeed • We can create fusion reactions on Earth! • We can measure the sun’s energy output • We know the processes causing this • We know how much fuel the sun has ...
Misalignment & Nucleosynthesis in Microquasars Yousaf M. Butt , Thomas J. Maccarone
... intimately linked. Since the position angles of microquasar orbital planes remain unmeasured, it is quite possible that, in certain cases, the jets lie close enough to their orbital planes so as to periodically impact the companion stars. eg. in V4641Sgr the jet axis is known to lie not more than ~3 ...
... intimately linked. Since the position angles of microquasar orbital planes remain unmeasured, it is quite possible that, in certain cases, the jets lie close enough to their orbital planes so as to periodically impact the companion stars. eg. in V4641Sgr the jet axis is known to lie not more than ~3 ...
The local density of matter mapped by Hipparcos
... 0:0 , M V , 2:5. These cuts are illustrated in Fig. 1. This results in 14 342 stars. Proper motions and parallaxes are available for all these stars. We further divide this sample into two at an absolute magnitude M V 1:0. We refer to these two samples as A and F stars. The first sample roughly ta ...
... 0:0 , M V , 2:5. These cuts are illustrated in Fig. 1. This results in 14 342 stars. Proper motions and parallaxes are available for all these stars. We further divide this sample into two at an absolute magnitude M V 1:0. We refer to these two samples as A and F stars. The first sample roughly ta ...
Determination of the distance to the Andromeda Galaxy using variable stars U
... distance ladder is the Astronomical Unit, which can be determined by a wealth of different methods and procedures, either direct or indirect. With the determination of the Astronomical Unit and with accurate astrometric parallaxes, the distance to neighboring stars can be directly determined. The mos ...
... distance ladder is the Astronomical Unit, which can be determined by a wealth of different methods and procedures, either direct or indirect. With the determination of the Astronomical Unit and with accurate astrometric parallaxes, the distance to neighboring stars can be directly determined. The mos ...
ms
... over the neutron star mass and radius peaks in two close regions in the mass-radius space, as shown in Figure 3. Even though we calculate the full probability distribution over these parameters, we show with filled contours the regions above M > 1.2M⊙ in Figure 3, which are astrophysically more rele ...
... over the neutron star mass and radius peaks in two close regions in the mass-radius space, as shown in Figure 3. Even though we calculate the full probability distribution over these parameters, we show with filled contours the regions above M > 1.2M⊙ in Figure 3, which are astrophysically more rele ...
A Horse of a Different Color
... star now illuminates the gas from which it formed. It is just one of many examples of star birth in and around the nebula. The long-term story of this dark nebula is about the action and reaction of a gas cloud to star formation. Stars form within dark nebulae. Hot newborn stars emit intense radiati ...
... star now illuminates the gas from which it formed. It is just one of many examples of star birth in and around the nebula. The long-term story of this dark nebula is about the action and reaction of a gas cloud to star formation. Stars form within dark nebulae. Hot newborn stars emit intense radiati ...
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.