Lecture 2: Theory - Laboratory for Atmospheric and Space Physics
... Where do cyclotron waves come from? Alfvén waves with frequencies > 10 Hz have not yet been observed in the corona or solar wind, but ideas for their origin abound . . . . (1) Base generation by, e.g., “microflare” reconnection in the lanes that border convection cells (e.g., Axford & McKenzie 1997 ...
... Where do cyclotron waves come from? Alfvén waves with frequencies > 10 Hz have not yet been observed in the corona or solar wind, but ideas for their origin abound . . . . (1) Base generation by, e.g., “microflare” reconnection in the lanes that border convection cells (e.g., Axford & McKenzie 1997 ...
ms
... To determine the mass and the radius of the neutron star in SAX J1748.9−2021, we follow the Bayesian method discussed in detail in Özel et al. (2009, 2012a). For each observable, we assign an independent probability distribution function. For the touchdown flux P (FT D )dFT D , the apparent angular ...
... To determine the mass and the radius of the neutron star in SAX J1748.9−2021, we follow the Bayesian method discussed in detail in Özel et al. (2009, 2012a). For each observable, we assign an independent probability distribution function. For the touchdown flux P (FT D )dFT D , the apparent angular ...
Theoretical and observational framework Spectroscopic approach
... Fabbian, Recio-Blanco et al. 2003, in preparation • Radiative levitation of metals and helium depletion is detected for HB stars hotter than ~11 000 K in NGC 1904 for the first time. Fe, Ti, Cr and other metal species are enhanced to supersolar values. He abundance below the solar value. • Slightly ...
... Fabbian, Recio-Blanco et al. 2003, in preparation • Radiative levitation of metals and helium depletion is detected for HB stars hotter than ~11 000 K in NGC 1904 for the first time. Fe, Ti, Cr and other metal species are enhanced to supersolar values. He abundance below the solar value. • Slightly ...
The evolution and explosion of massive stars
... holds the star up against the force of gravity, but because it radiates, the star evolves. When the interior is sufficiently hot, nuclear reactions provide the energy lost as radiation and neutrinos, but only by altering the composition so that the structure of the star changes with time. Nondegener ...
... holds the star up against the force of gravity, but because it radiates, the star evolves. When the interior is sufficiently hot, nuclear reactions provide the energy lost as radiation and neutrinos, but only by altering the composition so that the structure of the star changes with time. Nondegener ...
Asymptotic Giant Branch stars viewed up-close and far-off
... Observations of circumstellar H2 O are of particular interest, as it is expected to be one of the most abundant molecules in the inner envelopes of M-type AGB stars (with C/O<1). The first part of this thesis concerns the modelling of water vapour emission lines from CSEs around M-type AGB stars. Us ...
... Observations of circumstellar H2 O are of particular interest, as it is expected to be one of the most abundant molecules in the inner envelopes of M-type AGB stars (with C/O<1). The first part of this thesis concerns the modelling of water vapour emission lines from CSEs around M-type AGB stars. Us ...
L95 IRON-RICH EJECTA IN THE SUPERNOVA
... in each radial shell. The mean charge state of each species in the fit is calculated using the values quoted above for kT and ne t. For example, the mean number of electrons per ion is 11.8 for Si and 18.2 for Fe. The main uncertainty in converting EMs to Fe and Si density and mass estimates is not ...
... in each radial shell. The mean charge state of each species in the fit is calculated using the values quoted above for kT and ne t. For example, the mean number of electrons per ion is 11.8 for Si and 18.2 for Fe. The main uncertainty in converting EMs to Fe and Si density and mass estimates is not ...
Time evolution of snow regions and planet traps in an evolving
... and showed that if some specific conditions are met, the migration could be stopped in a steady-state α disk. Paardekooper & Papaloizou (2009a) estimated that almost any positive surface mass density gradient could act as a protoplanet trap. Zerotorque radii were later analyzed by Lyra et al. (2010) ...
... and showed that if some specific conditions are met, the migration could be stopped in a steady-state α disk. Paardekooper & Papaloizou (2009a) estimated that almost any positive surface mass density gradient could act as a protoplanet trap. Zerotorque radii were later analyzed by Lyra et al. (2010) ...
PS1-10jh: The Disruption of a Main-Sequence Star of Near
... a solar mass star is approximately one hour. Given an initial stellar model that occupies 1003 grid cells, each hydrodynamical time-step translates to only one minute of physical time. Thus, the simulation of the tidal disruption of a solar mass star by a 106 M black hole that includes the time at ...
... a solar mass star is approximately one hour. Given an initial stellar model that occupies 1003 grid cells, each hydrodynamical time-step translates to only one minute of physical time. Thus, the simulation of the tidal disruption of a solar mass star by a 106 M black hole that includes the time at ...
ly Searching the Sky: The Swift Mission and High Energy Physics Connections
... strong particle accelerating jets and/or wind interaction shocks, e.g. LS I +61303 ...
... strong particle accelerating jets and/or wind interaction shocks, e.g. LS I +61303 ...
THE YELLOW SUPERGIANT PROGENITOR OF THE TYPE II
... located 3 mas from the transformed position of the SN (within the 23 mas rms error of the transformation). In the WFPC2 pre-explosion F 336W image, Source A was detected at 4.4σ with mF 336W = 23.39 ± 0.25 (in flight system Vega magnitudes). In the drizzled ACS WFC images, Source A was measured to h ...
... located 3 mas from the transformed position of the SN (within the 23 mas rms error of the transformation). In the WFPC2 pre-explosion F 336W image, Source A was detected at 4.4σ with mF 336W = 23.39 ± 0.25 (in flight system Vega magnitudes). In the drizzled ACS WFC images, Source A was measured to h ...
ppt
... – We demonstrate the importance of sampling the full probability distribution of parameters in the stellar population synthesis modeling of galaxy spectra (i.e. MCMC in general give different results from chisq minimization). – Degeneracies between intrinsic dust extinction and other parameters esti ...
... – We demonstrate the importance of sampling the full probability distribution of parameters in the stellar population synthesis modeling of galaxy spectra (i.e. MCMC in general give different results from chisq minimization). – Degeneracies between intrinsic dust extinction and other parameters esti ...
ASTRONOMY AND ASTROPHYSICS Numerical simulations of stellar winds: polytropic models
... wind solution where the position of the critical point can be determined a priori. In practice, we increased the polytropic index gradually from γ = 1 through 1.05, 1.1, 1.12, 1.125 to γ = 1.13, each time relaxing the obtained steady-state solution for one polytropic index to the unique transonic wi ...
... wind solution where the position of the critical point can be determined a priori. In practice, we increased the polytropic index gradually from γ = 1 through 1.05, 1.1, 1.12, 1.125 to γ = 1.13, each time relaxing the obtained steady-state solution for one polytropic index to the unique transonic wi ...
Population synthesis of Be/white dwarf binaries in the Galaxy
... Tutukov & Yungelson (1973) and van den Heuvel & Heise (1972) (see recent review by van den Heuvel 1994). The continuous evolution of each binary component is treated as a sequence of a finite number of basic evolutionary states (for example, main sequence, red (super)giant, helium (Wolf-Rayet) star) ...
... Tutukov & Yungelson (1973) and van den Heuvel & Heise (1972) (see recent review by van den Heuvel 1994). The continuous evolution of each binary component is treated as a sequence of a finite number of basic evolutionary states (for example, main sequence, red (super)giant, helium (Wolf-Rayet) star) ...
GRAVITATIONAL SETTLING OF 22Ne AND WHITE DWARF
... attention is given to the treatment of the very outer layers of our models at advanced stages of evolution. This is crucial in determining absolute ages. In particular, compression of these layers constitutes the main energy source of the white dwarf when it enters the Debye regime. In the present c ...
... attention is given to the treatment of the very outer layers of our models at advanced stages of evolution. This is crucial in determining absolute ages. In particular, compression of these layers constitutes the main energy source of the white dwarf when it enters the Debye regime. In the present c ...
Galaxy Cosmological Mass Function
... LF Schechter parameters in the B-band, as well as this sample’s stellar mass-to-light ratio and its GSMF data. Results. Assuming Mg0 ≈ 1011 M⊙ as the local value of the average galactic mass, the LF approach results in L B ∝ (1 + z)(2.40±0.03) and Mg ∝ (1 + z)(1.1±0.2) . However, using the GSMF resu ...
... LF Schechter parameters in the B-band, as well as this sample’s stellar mass-to-light ratio and its GSMF data. Results. Assuming Mg0 ≈ 1011 M⊙ as the local value of the average galactic mass, the LF approach results in L B ∝ (1 + z)(2.40±0.03) and Mg ∝ (1 + z)(1.1±0.2) . However, using the GSMF resu ...
Star formation and the interstellar medium in galaxy
... more than a factor 103 , this temperature is effectively an upper limit to the gas temperature, virtually independent of the heat input. During the simulations the cooling time in some regions can become much shorter than the SPH time step, which is determined by the Courant-Friedrichs-Levy (CFL) co ...
... more than a factor 103 , this temperature is effectively an upper limit to the gas temperature, virtually independent of the heat input. During the simulations the cooling time in some regions can become much shorter than the SPH time step, which is determined by the Courant-Friedrichs-Levy (CFL) co ...
A Rigid-Field Hydrodynamics approach to modelling the
... of massive stars in the limit of very strong magnetic fields. Treating the field lines as effectively rigid, we develop hydrodynamical equations describing the one-dimensional flow along each, subject to pressure, radiative, gravitational and centrifugal forces. We solve these equations numerically ...
... of massive stars in the limit of very strong magnetic fields. Treating the field lines as effectively rigid, we develop hydrodynamical equations describing the one-dimensional flow along each, subject to pressure, radiative, gravitational and centrifugal forces. We solve these equations numerically ...
Jack Eddy`s Study of the Maunder Minimum Inspires a Long Series
... • Maunder Minimum (MM) period in late 1600s has lower solar activity – How much of the colder temperature (-0.4 K) during MM was driven by solar irradiance change? • Even if cycle minimum did not change during MM, Georg Feulner’s climate model (GRL, 2011) predicts a colder period because of cycle ...
... • Maunder Minimum (MM) period in late 1600s has lower solar activity – How much of the colder temperature (-0.4 K) during MM was driven by solar irradiance change? • Even if cycle minimum did not change during MM, Georg Feulner’s climate model (GRL, 2011) predicts a colder period because of cycle ...