Spinar Paradigm
... The proposed scenario allows the observed variety of gamma-ray bursts, precursors, and flares to be reduced to just two parameters: magnetic field and initial angular momentum. In the case of weak magnetic field and large angular momentum (the bottom-right corner) the first burst is weak (because of ...
... The proposed scenario allows the observed variety of gamma-ray bursts, precursors, and flares to be reduced to just two parameters: magnetic field and initial angular momentum. In the case of weak magnetic field and large angular momentum (the bottom-right corner) the first burst is weak (because of ...
Magnetic Fields in Stars
... the star 78 Virginis, a ‘chemically peculiar’ main sequence star (see STELLAR EVOLUTION) about twice as massive as the Sun. Magnetic fields are now known in perhaps 200 other A and B stars of the middle main sequence, all of which are, like 78 Vir, chemically peculiar (which means that they have ver ...
... the star 78 Virginis, a ‘chemically peculiar’ main sequence star (see STELLAR EVOLUTION) about twice as massive as the Sun. Magnetic fields are now known in perhaps 200 other A and B stars of the middle main sequence, all of which are, like 78 Vir, chemically peculiar (which means that they have ver ...
Hydrodynamic simulations with a radiative surface Atefeh Barekat
... correspond to the ionization energy of H− . Understanding the properties of the photosphere plays an important role of our knowledge about the structure of the Sun. This is due to the fact that the energy carried by convection can be radiated away in the photosphere. The chromosphere lies on top of ...
... correspond to the ionization energy of H− . Understanding the properties of the photosphere plays an important role of our knowledge about the structure of the Sun. This is due to the fact that the energy carried by convection can be radiated away in the photosphere. The chromosphere lies on top of ...
David L. Meier, , 84 (2001); DOI: 10.1126/science.291.5501.84
... more of power. Often, the twin jets are pointed at a large angle to our line of sight, allowing the full extent of the radio source powered by the jet—up to a few megaparsecs in size—to be seen. In a few sources, however, one of the jets points nearly directly toward Earth and the other points nearl ...
... more of power. Often, the twin jets are pointed at a large angle to our line of sight, allowing the full extent of the radio source powered by the jet—up to a few megaparsecs in size—to be seen. In a few sources, however, one of the jets points nearly directly toward Earth and the other points nearl ...
Slides
... the center of a galaxy which has a much higher than normal luminosity over some or all of the electromagnetic spectrum. The radiation from AGN is believed to be a result of accretion on to a super-massive black hole at the centre of the ...
... the center of a galaxy which has a much higher than normal luminosity over some or all of the electromagnetic spectrum. The radiation from AGN is believed to be a result of accretion on to a super-massive black hole at the centre of the ...
Coevolution of SMBHs and host galaxies at high z
... appears to be positively correlated with the local LAE density (96% confidence level). ...
... appears to be positively correlated with the local LAE density (96% confidence level). ...
Stars
... kilometers from the outside edge of the chromosphere and usually has a temperature of about 3 to 5 million K. ...
... kilometers from the outside edge of the chromosphere and usually has a temperature of about 3 to 5 million K. ...
Constraints on the Birth Aggregate of the Solar System
... Using the Monte Carlo technique outlined above, we have performed Nexp ≈ 50,000 scattering experiments for collisions between binary star systems and the outer solar system. These 7-body interactions involve all four giant planets, the Sun, and the two binary members. From the results of these exper ...
... Using the Monte Carlo technique outlined above, we have performed Nexp ≈ 50,000 scattering experiments for collisions between binary star systems and the outer solar system. These 7-body interactions involve all four giant planets, the Sun, and the two binary members. From the results of these exper ...
Absence of the strahl during times of slow wind
... φ–θ plots are used throughout this paper to illustrate features in the eVDFs. This mode of presentation allows one to show the entire three-dimensional distribution function at a given energy as a two-dimensional projection. The three columns of φ–θ plots in Fig. 1 serve as examples of some of the f ...
... φ–θ plots are used throughout this paper to illustrate features in the eVDFs. This mode of presentation allows one to show the entire three-dimensional distribution function at a given energy as a two-dimensional projection. The three columns of φ–θ plots in Fig. 1 serve as examples of some of the f ...
Radiative Processes in Astrophysics. Radio Polarization
... be calibrated by observations of sources with known integrated EVPA. Unfortunately no such sources are known on VLBI scales. Instead, we observe a source with compact polarization structure simultaneously with the VLBI array and with a single dish/connected-element interferometer. If the source has ...
... be calibrated by observations of sources with known integrated EVPA. Unfortunately no such sources are known on VLBI scales. Instead, we observe a source with compact polarization structure simultaneously with the VLBI array and with a single dish/connected-element interferometer. If the source has ...
On some properties of coronal mass ejections in solar cycle 23
... of cycle 23 was not significantly different from pre-SOHO observations. During solar minimum, one CME occurs every other day. The rate goes up to several per day during solar maximum. On one day during solar maximum, 13 CMEs were recorded by SOHO; there were several days with more than 10 CMEs (Gopa ...
... of cycle 23 was not significantly different from pre-SOHO observations. During solar minimum, one CME occurs every other day. The rate goes up to several per day during solar maximum. On one day during solar maximum, 13 CMEs were recorded by SOHO; there were several days with more than 10 CMEs (Gopa ...
Dr Conor Nixon Fall 2006
... Percival Lowell, the Martian canal sketcher in Arizona, to devote much energy and telescope time to hunting for planet #9. • Eventually, a 9th planet was discovered, as a result of Lowell’s persistent campaigning, and at Lowell Observatory in 1930, Pluto was first observed. In fact, the discovery wa ...
... Percival Lowell, the Martian canal sketcher in Arizona, to devote much energy and telescope time to hunting for planet #9. • Eventually, a 9th planet was discovered, as a result of Lowell’s persistent campaigning, and at Lowell Observatory in 1930, Pluto was first observed. In fact, the discovery wa ...
Growth of the inner core in the mean
... scales of the boundary layers, where helicity of the incompressible fluid is generated, are too small to generate the magnetic field. It means that extrapolation of helicity profiles to the realistic E can lead to the break of the magnetic field generation at all. However, in the compressible fluid ...
... scales of the boundary layers, where helicity of the incompressible fluid is generated, are too small to generate the magnetic field. It means that extrapolation of helicity profiles to the realistic E can lead to the break of the magnetic field generation at all. However, in the compressible fluid ...
CHANDRA on ,
... On the other hand, γ Cas is now known to be a wide binary with a ∼1 M star in a 203.59 day period orbit (Harmanec et al. 2000). This makes accretion very inefficient. According to current simulations (Okazaki et al. 2002), it is not possible to completely exclude the hypothesis in which matter is c ...
... On the other hand, γ Cas is now known to be a wide binary with a ∼1 M star in a 203.59 day period orbit (Harmanec et al. 2000). This makes accretion very inefficient. According to current simulations (Okazaki et al. 2002), it is not possible to completely exclude the hypothesis in which matter is c ...
Relationship between solar wind dynamic pressure and amplitude
... In the second stage after the passage of the compressional HM wave front tail-ward, the dawn-to-dusk electric field is enhanced by the enhanced magnetospheric convection in the compressed magnetosphere. This electric field produces the FACs and ICs, which flow in the opposite direction of the initia ...
... In the second stage after the passage of the compressional HM wave front tail-ward, the dawn-to-dusk electric field is enhanced by the enhanced magnetospheric convection in the compressed magnetosphere. This electric field produces the FACs and ICs, which flow in the opposite direction of the initia ...
The Plasma Environment of Mars (PDF Available)
... (2) The Magnetic Pileup Region (MPR) is a region dominated by planetary ions. A well-defined boundary, the Magnetic Pileup Boundary (MPB), separates the MPR from the magnetosheath. The MPB is a thin, sharp transition that deflects where the solar wind proton density drops sharply, but not the solar ...
... (2) The Magnetic Pileup Region (MPR) is a region dominated by planetary ions. A well-defined boundary, the Magnetic Pileup Boundary (MPB), separates the MPR from the magnetosheath. The MPB is a thin, sharp transition that deflects where the solar wind proton density drops sharply, but not the solar ...
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 ...
A Thermodynamic History of the Solar Constitution — II
... surface [1]. These words were to guide solar physics for two generations. For instance, in 1891, during his Inaugural Address before the British Association, William Huggins stated: “The Sun and stars are generally regarded as consisting of glowing vapours surrounded by a photosphere where condensat ...
... surface [1]. These words were to guide solar physics for two generations. For instance, in 1891, during his Inaugural Address before the British Association, William Huggins stated: “The Sun and stars are generally regarded as consisting of glowing vapours surrounded by a photosphere where condensat ...
3. Solar System Formation and Early Evolution
... hardest challenges for star formation theories: see Kroupa, 2002 for a review.) Depending on a number of external conditions, such as the total molecular cloud mass, the passage of a shock wave of a nearby supernova explosion from the most massive stars (see below), etc., the high-mass end of the IM ...
... hardest challenges for star formation theories: see Kroupa, 2002 for a review.) Depending on a number of external conditions, such as the total molecular cloud mass, the passage of a shock wave of a nearby supernova explosion from the most massive stars (see below), etc., the high-mass end of the IM ...
Plasma Diagnostics and Hydrodynamic Evolution of Solar Flares
... Firstly, I would like to acknowledge the Irish Research Council, the Fulbright Association and NASA’s Living With a Star Targeted Research and Technology Program for funding the research contained in this thesis. I would like to thank my supervisor, Prof. Peter Gallagher for giving me the opportunit ...
... Firstly, I would like to acknowledge the Irish Research Council, the Fulbright Association and NASA’s Living With a Star Targeted Research and Technology Program for funding the research contained in this thesis. I would like to thank my supervisor, Prof. Peter Gallagher for giving me the opportunit ...
Cosmological dynamics with non-minimally coupled scalar field and
... Measured breaks in the spectra of magnetic and density fluctuations at high frequencies are thought to be related to the transition from large-scale hydromagnetic to small-scale kinetic turbulence. The scales of such transitions and the responsible physical mechanisms are not well understood however ...
... Measured breaks in the spectra of magnetic and density fluctuations at high frequencies are thought to be related to the transition from large-scale hydromagnetic to small-scale kinetic turbulence. The scales of such transitions and the responsible physical mechanisms are not well understood however ...
Polarimetric evidence of a white dwarf pulsar in
... dwarf spin and the beat periods, are also consistent with this emission being produced in the white dwarf magnetosphere, which is additionally modulated at the binary period. The spectral energy distribution (SED) in AR Sco (2, 21) shows a Sν ∝ ν α1 (α1 ∼ 1.3) self-absorbed power law spectral distri ...
... dwarf spin and the beat periods, are also consistent with this emission being produced in the white dwarf magnetosphere, which is additionally modulated at the binary period. The spectral energy distribution (SED) in AR Sco (2, 21) shows a Sν ∝ ν α1 (α1 ∼ 1.3) self-absorbed power law spectral distri ...
Locating Geographic Coordinates Using Observations over the Sun
... duration varied with the date. The day with the fewest daylight hours was December 22. The lowest Sun height at noon was observed on December 25. More precise reference data suggested that in 2010 the Sun in Stavanger area was the lowest on December 22 (same as the shortest day). This discrepancy ca ...
... duration varied with the date. The day with the fewest daylight hours was December 22. The lowest Sun height at noon was observed on December 25. More precise reference data suggested that in 2010 the Sun in Stavanger area was the lowest on December 22 (same as the shortest day). This discrepancy ca ...
Roadmap for Solar System Science
... At the heart of the research undertaken by the communities represented by the Solar System Advisory Panel (SSAP) is a drive to understand the origin and evolution of the Solar System, and the nature of the phenomena that influence its dynamics. The remit of the SSAP covers all bodies in the Solar Sy ...
... At the heart of the research undertaken by the communities represented by the Solar System Advisory Panel (SSAP) is a drive to understand the origin and evolution of the Solar System, and the nature of the phenomena that influence its dynamics. The remit of the SSAP covers all bodies in the Solar Sy ...
Corona
A corona (Latin, 'crown') is an aura of plasma that surrounds the sun and other celestial bodies. The Sun's corona extends millions of kilometres into space and is most easily seen during a total solar eclipse, but it is also observable with a coronagraph. The word ""corona"" is a Latin word meaning ""crown"", from the Ancient Greek κορώνη (korōnē, “garland, wreath”).The high temperature of the Sun's corona gives it unusual spectral features, which led some in the 19th century to suggest that it contained a previously unknown element, ""coronium"". Instead, these spectral features have since been explained by highly ionized iron (Fe-XIV). Bengt Edlén, following the work of Grotrian (1939), first identified the coronal lines in 1940 (observed since 1869) as transitions from low-lying metastable levels of the ground configuration of highly ionised metals (the green Fe-XIV line at 5303 Å, but also the red line Fe-X at 6374 Å). These high stages of ionisation indicate a plasma temperature in excess of 1,000,000 kelvin, much hotter than the surface of the sun.Light from the corona comes from three primary sources, which are called by different names although all of them share the same volume of space. The K-corona (K for kontinuierlich, ""continuous"" in German) is created by sunlight scattering off free electrons; Doppler broadening of the reflected photospheric absorption lines completely obscures them, giving the spectral appearance of a continuum with no absorption lines. The F-corona (F for Fraunhofer) is created by sunlight bouncing off dust particles, and is observable because its light contains the Fraunhofer absorption lines that are seen in raw sunlight; the F-corona extends to very high elongation angles from the Sun, where it is called the zodiacal light. The E-corona (E for emission) is due to spectral emission lines produced by ions that are present in the coronal plasma; it may be observed in broad or forbidden or hot spectral emission lines and is the main source of information about the corona's composition.