What caused the GeV flare of PSR B1259-63?
... Methods. We compute the gamma-ray lightcurve for this scenario, based on a simplified description of the interaction region, and compare it to the observations. Results. The GeV lightcurve peaks well after periastron with this geometry. The pairs are inferred to have a Lorentz factor ≈500. They also ...
... Methods. We compute the gamma-ray lightcurve for this scenario, based on a simplified description of the interaction region, and compare it to the observations. Results. The GeV lightcurve peaks well after periastron with this geometry. The pairs are inferred to have a Lorentz factor ≈500. They also ...
Magneto-thermal Disk Wind from Protoplanetary Disks
... the main source of disk ionization, also serves as the dominant heating source at disk surface and the entire wind zone. Without considering magnetic fields, such heating is sufficiently strong to drive “photoevaporation” of PPDs, which has been considered as the dominant mechanism for PPD mass loss ...
... the main source of disk ionization, also serves as the dominant heating source at disk surface and the entire wind zone. Without considering magnetic fields, such heating is sufficiently strong to drive “photoevaporation” of PPDs, which has been considered as the dominant mechanism for PPD mass loss ...
Highest-Quality Surface Passivation of Low
... τeff value of 900 µs was obtained for the optimum gas flow ratio. This corresponds to a very low SRV < 10 cm/s. Hence, the surface passivation quality of the SiN films optimised in this work is equivalent to the best SiN passivation scheme reported to date [3-6]. The main difference of our optimised ...
... τeff value of 900 µs was obtained for the optimum gas flow ratio. This corresponds to a very low SRV < 10 cm/s. Hence, the surface passivation quality of the SiN films optimised in this work is equivalent to the best SiN passivation scheme reported to date [3-6]. The main difference of our optimised ...
astronomical oxygen isotopic evidence for supernova
... compared with the present-day Galaxy cannot be attributed to GCE over the past 4.6 billion years (the age of the solar system). A trend of decreasing [18 O]/[16 O] and [17 O]/[16 O] ratios at nearly constant [18 O]/[17 O] with increasing Galactocentric radius, RGC , was well established by early rad ...
... compared with the present-day Galaxy cannot be attributed to GCE over the past 4.6 billion years (the age of the solar system). A trend of decreasing [18 O]/[16 O] and [17 O]/[16 O] ratios at nearly constant [18 O]/[17 O] with increasing Galactocentric radius, RGC , was well established by early rad ...
Cosmological dynamics with non-minimally coupled scalar field and
... select a pilot sample of star-forming galaxies in the redshift range z = 2.00 − 2.65 whose multicomponent morphologies are consistent with expectations for major mergers. We follow up this sample of major merger candidates with Keck/NIRSPEC longslit spectroscopy obtained in excellent seeing conditio ...
... select a pilot sample of star-forming galaxies in the redshift range z = 2.00 − 2.65 whose multicomponent morphologies are consistent with expectations for major mergers. We follow up this sample of major merger candidates with Keck/NIRSPEC longslit spectroscopy obtained in excellent seeing conditio ...
SIMULATION OF QUIET-SUN WAVES IN THE Ca ii INFRARED TRIPLET
... The magnetic flux in the quiet Sun is very small (3 Mx cm2 in the internetwork; Lites 2002), so useful observations need a high signal-to-noise ratio (S/ N 103 ), which, when combined with the high time cadence required to resolve the wave propagation, imposes stringent demands on the instrument ...
... The magnetic flux in the quiet Sun is very small (3 Mx cm2 in the internetwork; Lites 2002), so useful observations need a high signal-to-noise ratio (S/ N 103 ), which, when combined with the high time cadence required to resolve the wave propagation, imposes stringent demands on the instrument ...
Radiato-Magneto-Thermal Winds from an Accretion Disk
... supposed streamlines and under Newtonian gravity. Such a disk wind is characterized by the disk gravitational and radiation fields, whose behavior is rather different from the spherical case. Along the streamline of winds, the gravitational field produced by the central object generally has a peak a ...
... supposed streamlines and under Newtonian gravity. Such a disk wind is characterized by the disk gravitational and radiation fields, whose behavior is rather different from the spherical case. Along the streamline of winds, the gravitational field produced by the central object generally has a peak a ...
Three-dimensional simulations of the upper
... 4 Department of Astronomy and Physics, Saint Mary’s University, Halifax, Nova Scotia B3A 4R2, Canada 2 Astronomy ...
... 4 Department of Astronomy and Physics, Saint Mary’s University, Halifax, Nova Scotia B3A 4R2, Canada 2 Astronomy ...
Light perturbation from stellar non radial oscillations: an application
... • Taking into account sphericity of the photosphere reveals a possible significant increase of the relative intensity perturbation at the solar limb for some modes of oscillation: - both for p and g-modes - and only for l+m even modes • The effect on the full-disk perturbation is expected to be smal ...
... • Taking into account sphericity of the photosphere reveals a possible significant increase of the relative intensity perturbation at the solar limb for some modes of oscillation: - both for p and g-modes - and only for l+m even modes • The effect on the full-disk perturbation is expected to be smal ...
SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS
... Precipitating particles deposit their energy into the Earth's atmosphere by ionization, excitation, dissociation, and heating of the neutral gas. High-energy electrons or ions impacting the nucleus of atoms or molecules can lead to an emission of an x-ray photon by bremsstrahlung with an energy comp ...
... Precipitating particles deposit their energy into the Earth's atmosphere by ionization, excitation, dissociation, and heating of the neutral gas. High-energy electrons or ions impacting the nucleus of atoms or molecules can lead to an emission of an x-ray photon by bremsstrahlung with an energy comp ...
EUV and X-ray Spectroscopy of the Active Sun
... were compared to a 0-D hydrodynamic model, EBTEL, to aid interpretation. This led to the conclusion that the flare was not heated purely by non-thermal beam heating as previously believed, but also required direct heating of the plasma. An observational investigation in to the initiation mechanism o ...
... were compared to a 0-D hydrodynamic model, EBTEL, to aid interpretation. This led to the conclusion that the flare was not heated purely by non-thermal beam heating as previously believed, but also required direct heating of the plasma. An observational investigation in to the initiation mechanism o ...
The magnetic field configuration of a solar prominence inferred from
... In Fig. 3 we sketch the geometry of the prominence. In particular, we show a top view of the prominence using STEREO-B contour lines (right side). The filament has a length of about 138 (∼100 Mm) and a width of 15 . The angle between the LOS and the long axis of the prominence is α = 90◦ + β, wh ...
... In Fig. 3 we sketch the geometry of the prominence. In particular, we show a top view of the prominence using STEREO-B contour lines (right side). The filament has a length of about 138 (∼100 Mm) and a width of 15 . The angle between the LOS and the long axis of the prominence is α = 90◦ + β, wh ...
Observations of ubiquitous compressive waves in the Sun`s
... hundreds of bright and dark fine structures, all displaying highly dynamic behaviour. The elongated structures are the fibrils and shorter structures are the mottles. Recent advances in the modelling of Hα line formation suggest the dark structures are regions of enhanced density that closely follow ...
... hundreds of bright and dark fine structures, all displaying highly dynamic behaviour. The elongated structures are the fibrils and shorter structures are the mottles. Recent advances in the modelling of Hα line formation suggest the dark structures are regions of enhanced density that closely follow ...
Global Properties of Solar Flares
... The idea that a solar disturbance could affect a terrestrial instrument such as a compass seemed highly improbable at the time, but it turned out to be indeed a correct association, so this first observed flare served to suggest immediately the capability for a such a solar event to have widely felt ...
... The idea that a solar disturbance could affect a terrestrial instrument such as a compass seemed highly improbable at the time, but it turned out to be indeed a correct association, so this first observed flare served to suggest immediately the capability for a such a solar event to have widely felt ...
Literature Review on the Formation of Active Regions
... In an early paper of 1955, Parker presented an idea about sunspot formation which could explain most properties of sunspots like their east-west orientation, bipolarity, their position in low latitudes (Spörer’s law) and the change of polarity inversion with time and latitude. He suggests that a la ...
... In an early paper of 1955, Parker presented an idea about sunspot formation which could explain most properties of sunspots like their east-west orientation, bipolarity, their position in low latitudes (Spörer’s law) and the change of polarity inversion with time and latitude. He suggests that a la ...
Stellar Wind Mechanisms and Instabilities
... One of the great astronomical discoveries of the latter half of the past century was the realization that nearly all stars lose mass through a more or less continuous surface outflow called a “stellar wind”. While it was long apparent that stars could eject material in dramatic outburts like novae o ...
... One of the great astronomical discoveries of the latter half of the past century was the realization that nearly all stars lose mass through a more or less continuous surface outflow called a “stellar wind”. While it was long apparent that stars could eject material in dramatic outburts like novae o ...
Document
... The Oort Cloud The reservoir for long-period comets • Discovered in 1950 • This is much further out! – 50,000 AU distant! ...
... The Oort Cloud The reservoir for long-period comets • Discovered in 1950 • This is much further out! – 50,000 AU distant! ...
Effects of M dwarf magnetic fields on potentially habitable planets
... Theoretically, the efficiency of a planetary dynamo is related to its interior structure: it should possess an electrically conducting region and a convective flow (e.g., Stevenson 2003). Contrary to past beliefs, recent studies indicate that the planetary field strength is independent of rotation r ...
... Theoretically, the efficiency of a planetary dynamo is related to its interior structure: it should possess an electrically conducting region and a convective flow (e.g., Stevenson 2003). Contrary to past beliefs, recent studies indicate that the planetary field strength is independent of rotation r ...
$doc.title
... Theoretically, the efficiency of a planetary dynamo is related to its interior structure: it should possess an electrically conducting region and a convective flow (e.g., Stevenson 2003). Contrary to past beliefs, recent studies indicate that the planetary field strength is independent of rotation r ...
... Theoretically, the efficiency of a planetary dynamo is related to its interior structure: it should possess an electrically conducting region and a convective flow (e.g., Stevenson 2003). Contrary to past beliefs, recent studies indicate that the planetary field strength is independent of rotation r ...
X-ray Emission Line Profiles from ... Confined Wind Shock Model
... field. Our analytic models produce simplified, steady-state velocity and density profiles of a structured wind, and our simulations provide time-dependent values for temperature, velocity, and density at points throughout the wind. The information from each of these methods allows us to determine wh ...
... field. Our analytic models produce simplified, steady-state velocity and density profiles of a structured wind, and our simulations provide time-dependent values for temperature, velocity, and density at points throughout the wind. The information from each of these methods allows us to determine wh ...
RAL Space - Science and Technology Facilities Council
... Cluster is an ESA mission, revolutionising our understanding of the interaction between electrically charged particles from the Sun and the Earth's magnetic field. The four Cluster spacecraft were launched in pairs on 16 July and 9 August 2000 and now orbit the Earth in formation. This unique set of ...
... Cluster is an ESA mission, revolutionising our understanding of the interaction between electrically charged particles from the Sun and the Earth's magnetic field. The four Cluster spacecraft were launched in pairs on 16 July and 9 August 2000 and now orbit the Earth in formation. This unique set of ...
Interacting supernovae from photoionization
... The agreement of Betelgeuse’s neutral shell with our photoionizationconfined shell calculations is encouraging, but further work is required to investigate multidimensional effects such as the non-radial flows that are introduced by clumpy and asymmetric winds16, the dynamical stability of the shock ...
... The agreement of Betelgeuse’s neutral shell with our photoionizationconfined shell calculations is encouraging, but further work is required to investigate multidimensional effects such as the non-radial flows that are introduced by clumpy and asymmetric winds16, the dynamical stability of the shock ...
Chandra HETGS Multiphase Spectroscopy Of The Young
... the field still manages to divert some material toward the magnetic equator, leading to a noticeable density enhancement. Because the magnetic field energy density falls off significantly faster than the wind kinetic energy density, at large radii the wind always dominates over the field, even for ...
... the field still manages to divert some material toward the magnetic equator, leading to a noticeable density enhancement. Because the magnetic field energy density falls off significantly faster than the wind kinetic energy density, at large radii the wind always dominates over the field, even for ...
Clumpy wind accretion in supergiant neutron star high mass X
... X-ray radiation to be compared with observations of isolated OB supergiants and massive stars in SGXBs (see, e.g., Puls et al. 2008). More recent findings seem to suggest that clumps might likely be limited to a density ratio of ∼10 compared to the surrounding medium and a lateral extent of the orde ...
... X-ray radiation to be compared with observations of isolated OB supergiants and massive stars in SGXBs (see, e.g., Puls et al. 2008). More recent findings seem to suggest that clumps might likely be limited to a density ratio of ∼10 compared to the surrounding medium and a lateral extent of the orde ...
Ons sonnestelsel is geskape
... “Once these planetestimals have been formed, further growth of planets may occur through their gravitational accretion into large bodies. Just how that takes place is not understood.” Martin Harwit, Astrophysical Concepts, 2 nd Ed, p 533 ...
... “Once these planetestimals have been formed, further growth of planets may occur through their gravitational accretion into large bodies. Just how that takes place is not understood.” Martin Harwit, Astrophysical Concepts, 2 nd Ed, p 533 ...
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.