Circumstellar medium around rotating massive stars at solar metallicity
... transfer codes, together with tools of data analysis and visualisation. This toolbox is validated well in that it has been used for a variety of different astrophysical flow and radiative transfer problems: colliding winds in binaries (Nussbaumer & Walder 1993; Walder 1998) and their spectral respon ...
... transfer codes, together with tools of data analysis and visualisation. This toolbox is validated well in that it has been used for a variety of different astrophysical flow and radiative transfer problems: colliding winds in binaries (Nussbaumer & Walder 1993; Walder 1998) and their spectral respon ...
master thesis
... Nonetheless the lunar surface is covered by dust, which is a major drawback to overcome due to its abrasiveness, pervasive nature and gravitational settling on optical lens and solar cells among other instruments, degrading their performance. These dust particles are tiny (< 20 μm in diameter) and e ...
... Nonetheless the lunar surface is covered by dust, which is a major drawback to overcome due to its abrasiveness, pervasive nature and gravitational settling on optical lens and solar cells among other instruments, degrading their performance. These dust particles are tiny (< 20 μm in diameter) and e ...
The magnetic field and wind confinement of b Cephei: new clues for
... also hosts an oblique magnetic field and thus a dense magnetosphere, is very natural, and may yield some insights into the recurrent Be episodes that this star undergoes every few decades, the latest recorded event being dated from early 1990 (Mathias, Gillet & Kaper 1991). It could also provide a n ...
... also hosts an oblique magnetic field and thus a dense magnetosphere, is very natural, and may yield some insights into the recurrent Be episodes that this star undergoes every few decades, the latest recorded event being dated from early 1990 (Mathias, Gillet & Kaper 1991). It could also provide a n ...
Magnetic quenching of turbulent diffusivity - Andrés Muñoz
... theoretical estimate and the typical values used inside the convection zone (around two orders of magnitude difference). This creates a problem that is aggravated by the fact that dynamo models simply cannot operate under very strong diffusivities as suggested by MLT. A possible solution for this in ...
... theoretical estimate and the typical values used inside the convection zone (around two orders of magnitude difference). This creates a problem that is aggravated by the fact that dynamo models simply cannot operate under very strong diffusivities as suggested by MLT. A possible solution for this in ...
Circum-stellar medium around rotating massive stars at solar
... curved manifolds for the case of ideal hydrodynamics (Euler equations). The grid is constructed on the basis of a Cartesian parameter space and a generic, not necessarily differentiable map from this parameter space to the physical space. The advantage of this procedure is that the adaptive mesh alg ...
... curved manifolds for the case of ideal hydrodynamics (Euler equations). The grid is constructed on the basis of a Cartesian parameter space and a generic, not necessarily differentiable map from this parameter space to the physical space. The advantage of this procedure is that the adaptive mesh alg ...
Sun, Stars and Planets Part 1: The Sun: its structure and energy
... 3.1.2 Stellar plasma: an ideal gas and local thermodynamic equilibrium, radiation The stellar material is an ionised gas or plasma, and is assumed to be an ideal gas. Because of the high T in stars all but the most tightly bound electrons are separated from the atoms. This allows a greater compressi ...
... 3.1.2 Stellar plasma: an ideal gas and local thermodynamic equilibrium, radiation The stellar material is an ionised gas or plasma, and is assumed to be an ideal gas. Because of the high T in stars all but the most tightly bound electrons are separated from the atoms. This allows a greater compressi ...
STELLAR SPECTRA A. Basic Line Formation
... development of more general line-formation theory, especially radiation transport through resonance scattering; – Avrett, Auer, Mihalas, Hummer, Rybicki and many others, from 1965: application of computers to model non-LTE line formation numerically. ...
... development of more general line-formation theory, especially radiation transport through resonance scattering; – Avrett, Auer, Mihalas, Hummer, Rybicki and many others, from 1965: application of computers to model non-LTE line formation numerically. ...
Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds
... Diagram • The Sun: coronal heating & fast solar wind • Hot stars (O, B, W-R): pulsations & radiation-driving • Cool stars (T Tau, Mira): chromospheric flows? Steven R. Cranmer & many others ...
... Diagram • The Sun: coronal heating & fast solar wind • Hot stars (O, B, W-R): pulsations & radiation-driving • Cool stars (T Tau, Mira): chromospheric flows? Steven R. Cranmer & many others ...
overview of the new horizons science payload
... power, and highly sensitive instruments. Pluto will be nearly 33 AU from the sun at the time of the encounter in 2015, and a launch energy (C3) of nearly 170 km2 s-2 was needed to reach this distance within the 9.5 year transit to the Pluto system. Even using the powerful Lockheed-Martin Atlas 551 l ...
... power, and highly sensitive instruments. Pluto will be nearly 33 AU from the sun at the time of the encounter in 2015, and a launch energy (C3) of nearly 170 km2 s-2 was needed to reach this distance within the 9.5 year transit to the Pluto system. Even using the powerful Lockheed-Martin Atlas 551 l ...
payload_ssr
... power, and highly sensitive instruments. Pluto will be nearly 33 AU from the sun at the time of the encounter in 2015, and a launch energy (C3) of nearly 170 km2 s-2 was needed to reach this distance within the 9.5 year transit to the Pluto system. Even using the powerful Lockheed-Martin Atlas 551 l ...
... power, and highly sensitive instruments. Pluto will be nearly 33 AU from the sun at the time of the encounter in 2015, and a launch energy (C3) of nearly 170 km2 s-2 was needed to reach this distance within the 9.5 year transit to the Pluto system. Even using the powerful Lockheed-Martin Atlas 551 l ...
A search for the cause of cyclical wind variability in O stars
... Hα line profiles. The epochs of maximum absorption in the UV resonance lines due to discrete absorption components (DACs) coincide in phase with the maxima in blue-shifted Hα absorption. This implies that the periodic variability originates close to the stellar surface. The phase−velocity relation s ...
... Hα line profiles. The epochs of maximum absorption in the UV resonance lines due to discrete absorption components (DACs) coincide in phase with the maxima in blue-shifted Hα absorption. This implies that the periodic variability originates close to the stellar surface. The phase−velocity relation s ...
Pulsed high-energy γ-rays from thermal populations in the current
... In those models, the emission originates within the light cylinder, defined by the cylindrical radius rLC = c/ω from the pulsar’s rotational axis, where a corotating particle would reach the speed of light. However, it was pointed out by Bai & Spitkovsky (2010) that the emission region must be exten ...
... In those models, the emission originates within the light cylinder, defined by the cylindrical radius rLC = c/ω from the pulsar’s rotational axis, where a corotating particle would reach the speed of light. However, it was pointed out by Bai & Spitkovsky (2010) that the emission region must be exten ...
Venus express: Highlights of the nominal mission - HAL
... successful Mars Express bus—a 600 kg 3-axis stabilized platform with two body-fixed telecommunication antennas (Fig. 1). The spacecraft is described in detail by Svedhem et al. (2007a, 2008). Most of the subsystems and payloads are mounted on its walls and on panels inside the bus, while ASPERA and ...
... successful Mars Express bus—a 600 kg 3-axis stabilized platform with two body-fixed telecommunication antennas (Fig. 1). The spacecraft is described in detail by Svedhem et al. (2007a, 2008). Most of the subsystems and payloads are mounted on its walls and on panels inside the bus, while ASPERA and ...
The Plasma Physics Processes that Drive Ring Current
... Figure 5.3 Parameters used to monitor conditions for the 10 March 1998 storm............... 66 Figure 5.4 Foot point mapping of ring current ions mapped back to the polar cap. ........... 67 Figure 5.5 Results for hydrogen and oxygen ions for the main phase of the storm............ 68 Figure 5.6 Res ...
... Figure 5.3 Parameters used to monitor conditions for the 10 March 1998 storm............... 66 Figure 5.4 Foot point mapping of ring current ions mapped back to the polar cap. ........... 67 Figure 5.5 Results for hydrogen and oxygen ions for the main phase of the storm............ 68 Figure 5.6 Res ...
Properties of Galactic B supergiants
... (e.g. Mokiem et al. 2006ab). Unfortunately, O dwarfs are visually faint in external galaxies due to their large bolometric corrections and small radii, with typically MV = -5.0 mag. O star abundances of CNO elements are difficult to derive (Crowther et al. 2002), yet these are sensitive to early rot ...
... (e.g. Mokiem et al. 2006ab). Unfortunately, O dwarfs are visually faint in external galaxies due to their large bolometric corrections and small radii, with typically MV = -5.0 mag. O star abundances of CNO elements are difficult to derive (Crowther et al. 2002), yet these are sensitive to early rot ...
Catastrophic evaporation of rocky planets
... the star from the substellar point on the planet. The substellar ray is of special interest because the mass flux it carries will be maximal insofar as the substellar point has the highest temperature – and thus the highest rate of rock sublimation – and insofar as stellar gravity will act most stro ...
... the star from the substellar point on the planet. The substellar ray is of special interest because the mass flux it carries will be maximal insofar as the substellar point has the highest temperature – and thus the highest rate of rock sublimation – and insofar as stellar gravity will act most stro ...
PPT
... • For “standard” young pulsars, we expect pulsar wind nebulae - properties of nebulae point to properties of neutron star - high resolution X-ray studies reveal neutron stars, termination shock from pulsar wind, equatorial and axial structures (i.e. jets) • Jets are often curved and show variable st ...
... • For “standard” young pulsars, we expect pulsar wind nebulae - properties of nebulae point to properties of neutron star - high resolution X-ray studies reveal neutron stars, termination shock from pulsar wind, equatorial and axial structures (i.e. jets) • Jets are often curved and show variable st ...
スライド 1
... Looking down onto the ecliptic plane from above, a CIR near Earth's orbit is sketched. The Sun is off the bottom of the figure. The CIR is shaded in tan, and the Earth's track through the CIR is depicted as the green dashed line. In the reference frame of this sketch, the Earth moves downward with t ...
... Looking down onto the ecliptic plane from above, a CIR near Earth's orbit is sketched. The Sun is off the bottom of the figure. The CIR is shaded in tan, and the Earth's track through the CIR is depicted as the green dashed line. In the reference frame of this sketch, the Earth moves downward with t ...
8th International Workshop on Planetary, Solar and Heliospheric
... the Scientific Organizing Committee (SOC) is pleased to welcome you to our 8th International Workshop on Planetary, Solar and Heliospheric Radio Emissions, commonly known as “PRE 8”. Previous PRE meetings all took place in Graz in the years 1984, 1987, 1991, 1996, 2001, 2005 and 2010. This is the fi ...
... the Scientific Organizing Committee (SOC) is pleased to welcome you to our 8th International Workshop on Planetary, Solar and Heliospheric Radio Emissions, commonly known as “PRE 8”. Previous PRE meetings all took place in Graz in the years 1984, 1987, 1991, 1996, 2001, 2005 and 2010. This is the fi ...
Winds from accretion disks driven by the radiation and
... Drew 1998, hereafter PSD I; Proga 1999; Proga, Stone & Drew 1999, hereafter PSD II). These recent studies showed that radiation pressure due to spectral lines can drive winds from luminous disks. This result has been expected (e.g., Vitello & Shlosman 1988). These studies, in particular those by PSD ...
... Drew 1998, hereafter PSD I; Proga 1999; Proga, Stone & Drew 1999, hereafter PSD II). These recent studies showed that radiation pressure due to spectral lines can drive winds from luminous disks. This result has been expected (e.g., Vitello & Shlosman 1988). These studies, in particular those by PSD ...
Abstract: - Laboratory for Atmospheric and Space Physics
... prevail. If reconnection of open flux does proceed, then the field line tension associated with the ...
... prevail. If reconnection of open flux does proceed, then the field line tension associated with the ...
Lillis_et_al-2010-Journal_of_G
... developed for airless bodies by Anderson et al. [1976], and extended for use in a planetary atmosphere by Lillis et al. [2004, 2008b]. We summarize it below, presenting a model for loss cone formation, the parameters of which may be constrained by least squares fitting to loss cones measured by MAG/ ...
... developed for airless bodies by Anderson et al. [1976], and extended for use in a planetary atmosphere by Lillis et al. [2004, 2008b]. We summarize it below, presenting a model for loss cone formation, the parameters of which may be constrained by least squares fitting to loss cones measured by MAG/ ...
Latitudinal and radial gradients of galactic cosmic ray protons in the
... and tilt angle (red curve), respectively, indicating a period of several years of very low solar activity. Marked by shading are two periods after the launch of the PAMELA spacecraft in October 2006 and July 2008 when Ulysses was at about 3.5 AU and 50◦ . The polar passes are defined to be those per ...
... and tilt angle (red curve), respectively, indicating a period of several years of very low solar activity. Marked by shading are two periods after the launch of the PAMELA spacecraft in October 2006 and July 2008 when Ulysses was at about 3.5 AU and 50◦ . The polar passes are defined to be those per ...
Estimation of picked-up lunar ions for future compositional remote SIMS
... and asteroids maintain thin and sometimes transient atmospheres. Of these bodies, the Moon and its atmosphere have been the most extensively investigated, and the findings are thought to be the cornerstone on which to build studies of the other celestial bodies. The lunar atmosphere is called ‘surfa ...
... and asteroids maintain thin and sometimes transient atmospheres. Of these bodies, the Moon and its atmosphere have been the most extensively investigated, and the findings are thought to be the cornerstone on which to build studies of the other celestial bodies. The lunar atmosphere is called ‘surfa ...
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 ...
Solar wind
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun. This plasma consists of mostly electrons, protons and alpha particles with energies usually between 1.5 and 10 keV; embedded in the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over solar longitude. Its particles can escape the Sun's gravity because of their high energy, from the high temperature of the corona and magnetic, electrical and electromagnetic phenomena in it.The solar wind flows outward supersonically to great distances, filling a region known as the heliosphere, an enormous bubble-like volume surrounded by the interstellar medium. Other related phenomena include the aurora (northern and southern lights), the plasma tails of comets that always point away from the Sun, and geomagnetic storms that can change the direction of magnetic field lines and create strong currents in power grids on Earth.