A propelling neutron star in the enigmatic Be-star γ Cassiopeia
... energy into the shell at the propeller stage. Clearly, once ωm → ω∗ during the NS spin-down, the mechanical energy supply to the shell should vanish. However, even in this case the shell can be kept hot due to the gravitational energy release given by equation (2). To provide X-ray luminosity at the ...
... energy into the shell at the propeller stage. Clearly, once ωm → ω∗ during the NS spin-down, the mechanical energy supply to the shell should vanish. However, even in this case the shell can be kept hot due to the gravitational energy release given by equation (2). To provide X-ray luminosity at the ...
Tidal Disruptions of White Dwarfs from Ultra
... to solve the Einstein equations of general relativity and hydrodynamics. We do not include nuclear reactions. For the ultra-close encounters of our interest, with Rp ∼ few Rg , a general relativistic description of gravity is needed. However, given the mass ratio Mwd /Mbh ≃ 10−3 of the bodies involv ...
... to solve the Einstein equations of general relativity and hydrodynamics. We do not include nuclear reactions. For the ultra-close encounters of our interest, with Rp ∼ few Rg , a general relativistic description of gravity is needed. However, given the mass ratio Mwd /Mbh ≃ 10−3 of the bodies involv ...
The distribution of the ISM in the Milky Way A three
... the gas in the Milky Way. By assuming exponential axisymmetric distributions for the dust and the stars and by performing the corresponding radiative transfer calculations we closely (given the simple geometry of the model) reproduce the FIR and NIR maps of the Milky Way. Similar distributions for t ...
... the gas in the Milky Way. By assuming exponential axisymmetric distributions for the dust and the stars and by performing the corresponding radiative transfer calculations we closely (given the simple geometry of the model) reproduce the FIR and NIR maps of the Milky Way. Similar distributions for t ...
pdf-file - Max-Planck-Institut für Astronomie
... radius by turbulent disk self-heating of more than 10 AU, a radius, which is 3 times larger than that caused by stellar irradiation. We discuss implications of this result on the flashlight effect and the consequences for the radiation pressure of the central star. In deference to disks around low-m ...
... radius by turbulent disk self-heating of more than 10 AU, a radius, which is 3 times larger than that caused by stellar irradiation. We discuss implications of this result on the flashlight effect and the consequences for the radiation pressure of the central star. In deference to disks around low-m ...
Identifying Young far from Giant Stars Molecular Clouds
... other stars do. Thus, even binaries of advanced age can still have a high rotation rate and a large amount of x-ray emission. To rule out contamination, we use other techniques in distinguishing stellar youth, such as lithium abundance. The changes in T Tauri stars' lithium abundance results from th ...
... other stars do. Thus, even binaries of advanced age can still have a high rotation rate and a large amount of x-ray emission. To rule out contamination, we use other techniques in distinguishing stellar youth, such as lithium abundance. The changes in T Tauri stars' lithium abundance results from th ...
Document
... Combination of Boltzmann & Saha eqns specify state of gas completely Iteration for each state and level Plasma where all populations specified by T and Ne is said to be in Local Thermodynamic Equilibrium (LTE) Often assumed as an approximation in atmosphere modelling M.R. Burleigh 2601/Unit ...
... Combination of Boltzmann & Saha eqns specify state of gas completely Iteration for each state and level Plasma where all populations specified by T and Ne is said to be in Local Thermodynamic Equilibrium (LTE) Often assumed as an approximation in atmosphere modelling M.R. Burleigh 2601/Unit ...
Astronomy Astrophysics - Utrecht University Repository
... values in magnitude and colour correspond to the epoch when minimum flux is observed, presumably the photospheric flux. The object seems to have completed a full variability cycle in about 2 years. Fraction wise, some 40% of the Be stars in our sample that have an amplitude of variability larger tha ...
... values in magnitude and colour correspond to the epoch when minimum flux is observed, presumably the photospheric flux. The object seems to have completed a full variability cycle in about 2 years. Fraction wise, some 40% of the Be stars in our sample that have an amplitude of variability larger tha ...
mass and temperature of the twa 7 debris disk
... we construct the spectral energy distribution (SED) for this source ( Fig. 1). The submillimeter data clearly represent an excess of emission over the photospheric emission from TWA 7, as detected at 70 m by Low et al. (2005). The flux we measure at 850 m is only about 70% that measured by Webb (2 ...
... we construct the spectral energy distribution (SED) for this source ( Fig. 1). The submillimeter data clearly represent an excess of emission over the photospheric emission from TWA 7, as detected at 70 m by Low et al. (2005). The flux we measure at 850 m is only about 70% that measured by Webb (2 ...
Numerical Star-Formation Studies-
... order of magnitude, and both greatly exceed the thermal energy density. If molecular clouds form in large-scale convergent flows (as we argue below in Section II.B), then surface terms from ram pressure can also be significant and need to be considered in the virial equations (Ballesteros-Paredes, 2 ...
... order of magnitude, and both greatly exceed the thermal energy density. If molecular clouds form in large-scale convergent flows (as we argue below in Section II.B), then surface terms from ram pressure can also be significant and need to be considered in the virial equations (Ballesteros-Paredes, 2 ...
Chemical tagging of three distinct populations of red giants in the
... 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 made adopting the same fibre positioning ...
... 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 made adopting the same fibre positioning ...
ppt - chris.engelbrecht.nithep.ac.za
... calculate the age. How does this compare in the Sedov phase of evolution, ...
... calculate the age. How does this compare in the Sedov phase of evolution, ...
THE HOBBY-EBERLY TELESCOPE CHEMICAL ABUNDANCES OF
... The high Li abundance can be explained by self-enrichment through extra mixing that connects the convective envelope with the outer regions of the H-burning shell. If so, HKII 1743500532 is the most metal-poor star in which this short-lived phase of Li enrichment has been observed. The Na and n-cap ...
... The high Li abundance can be explained by self-enrichment through extra mixing that connects the convective envelope with the outer regions of the H-burning shell. If so, HKII 1743500532 is the most metal-poor star in which this short-lived phase of Li enrichment has been observed. The Na and n-cap ...
Today Only, A New Exhibit: M,L, and T Dwarfs!
... Mass <~ 75 Jupiter Masses which is 8 percent of our Sun's mass Burns Deuterium at >~ 13 Jupiter Masses for ~ 10’s of Myrs heating from contraction Highly convective Hot Corona may disappear around 2770 K i.e. LP 944-20 ...
... Mass <~ 75 Jupiter Masses which is 8 percent of our Sun's mass Burns Deuterium at >~ 13 Jupiter Masses for ~ 10’s of Myrs heating from contraction Highly convective Hot Corona may disappear around 2770 K i.e. LP 944-20 ...
A wide Chandra view of the core of the Perseus cluster
... there is a progressive steep increase of bubbles radius with distance from the nucleus (see also Randall et al 2011 for a sequence of bubbles in an elliptical galaxy). Diehl et al (2008) discuss bubbles which are continuously fed energy from the nucleus, which seems unlikely for Perseus. We note tha ...
... there is a progressive steep increase of bubbles radius with distance from the nucleus (see also Randall et al 2011 for a sequence of bubbles in an elliptical galaxy). Diehl et al (2008) discuss bubbles which are continuously fed energy from the nucleus, which seems unlikely for Perseus. We note tha ...
Richard Congdon. pdf
... (Iocco et al, 2009). With the formation of deuterium, other reactions become possible, all with nuclear binding energies above (more negative than) that of deuterium (see Figure 5), so if the temperature is low enough for deuterium to form then these other products will also form. The primary end pr ...
... (Iocco et al, 2009). With the formation of deuterium, other reactions become possible, all with nuclear binding energies above (more negative than) that of deuterium (see Figure 5), so if the temperature is low enough for deuterium to form then these other products will also form. The primary end pr ...
X-Ray and Extreme Ultraviolet Emission from Comets
... Astrophysical X-ray emission is generally found to originate from hot collisional plasmas, such as the million-degree gas found in the solar corona (e.g., Foukal, 1990), the 100million-degree gas observed in supernova remnants (e.g., Cioffi, 1990), or the accretion disks around neutron stars and bla ...
... Astrophysical X-ray emission is generally found to originate from hot collisional plasmas, such as the million-degree gas found in the solar corona (e.g., Foukal, 1990), the 100million-degree gas observed in supernova remnants (e.g., Cioffi, 1990), or the accretion disks around neutron stars and bla ...