... The Secret of the Black Aurora . ... 1.01.2002 . ... These gaps in normal bright aurora are frequently recorded but rarely questioned. Recent research using data from four Cluster spacecraft orbiting the Earth has now likely found the secret: black auroras are actually anti-auroras. ... In black anti-auroras, however, negatively charged particles are sucked out from the Earth's ionosphere along adjoining magnetic field lines. ... 2001 2002 . ... Publications with keywords: aurora - black aurora . ...

... 2002 January 1 . The Secret of the Black Aurora . ... Explanation: What causes black aurora? These gaps in normal bright aurora are frequently recorded but rarely questioned. Recent research using data from four Cluster spacecraft orbiting the Earth has now likely found the secret: black auroras are actually anti-auroras. ... In black anti-auroras, however, negatively charged particles are sucked out from the Earth's ionosphere along adjoining magnetic field lines. ... About APOD | ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... September Perseid meteors captured by the . ... Its occurrence provides astronomers with interesting new data about the hidden trails of meteoroids тАФ small bodies ranging in size from fine dust particles to objects of marble-size and larger тАФ in the solar system and their supposed sources: comets and asteroids passing through the inner solar system. ... The particular comet that created the September Perseids is unknown...

... Large . ... Normal . ... Thumbnails . ... Enter: Large | ... Contents with thumbnails: Large | ... Florence streets . ... Rome. ... Sunday, 12 September. ... Monday, 13 September. ... Tuesday, 14 September. ... Wednesday, 15 September. ... Thuesday, 16 September. ... Friday, 17 September. ... Saturday, 18 September. ... There's also index of the complete set of photos with thumbnails. ... return to photo album contents | ...

We cannot observe the way the distant universe accelerates cosmic rays or produces energetic photons, but acceleration processes also occur on our Sun , though on a much more moderate scale. ... That is why such events are often missed by cosmic ray detectors near the equator, where the lowest energies are excluded by the Earth's magnetic field. The best detectors for observing solar particles are therefore those sensitive to the lowest energies of the cosmic radiation. ...

... We use the first XMM serendipitous source catalogue (1XMM) to compile a sample of normal X-ray galaxies . ... We combine our emission line sample with earlier works forming the most comprehensive X-ray selected galaxy sample for the study of the X-ray luminosity to the H? luminosity - a well-calibrated star-formation indicator - relation. ... We find that the X-ray luminosity strongly correlates with the H? luminosity, suggesting that the X-rays efficiently trace the star-formation. | ...

... The TRACE images may be used without restrictions in publications of any kind. ... These two images, taken on 18 November 2000 at 15:54UT and 16:11UT, respectively, show such an event: the red circle in the image to the left shows a region where many loops are cooling, with bright loop tops (the intensity scales with the square root of the image to reduce the dynamic range). ... See also a collection of images related to the Sun, other cool stars, and solar-terrestrial effects . ... Images | ...

... Text algorithms, pattern matching, computationnal biology, comparative genomics . ... Ph.D. in Computer Science, October 1999. ... G. Navarro and M. Raffinot. ... A. Bergeron, C. Chauve, F. de Montgolfier and M. Raffinot. ... M. Habib and C. Paul and M. Raffinot. ... In Proceedings of the 15th Annual Symposium on Combinatorial Pattern Matching, number 3109 in Lecture Notes in Computer Science. Springer-Verlag, Berlin, 2004. ... In Theoretical Computer Science , 320(2-3), pages 955-418, 2004. ...

XMM-Newton Science Analysis System . ... Meta Index / Home Page / Description / Out-of-time events . If withoutoftime =y the task does not create the ``normal'' events file but uses the input file instead to create an event file where all events are treated as out-of-time events. ... Similarly, for Full Frame and Extended Full Frame modes (currently) the 11 rows closest to the CAMEX are set bad onboard but sources in these rows may also cause unrecognized out-of-time events. ...

... Magnetic Storms . ... Cosmic Rays . ... Energetic Particles . ... Solar fast Particles . We cannot observe the way the distant universe accelerates cosmic rays or produces energetic photons, but acceleration processes also occur on our Sun , though on a much more moderate scale. ... That is why such events are often missed by cosmic ray detectors near the equator, where the lowest energies are excluded by the Earth's magnetic field. ... Should we be concerned about solar energetic radiation? ...

... MIPT Solid State Physics Department . ... Interacting Electrons in Normal Metals . ... The course is an introduction to interacting Fermi-particle physics and intended for future experimentalists. ... Hartree-Fock approximation. ... Linear reaction function. Calculation of density-density reaction function. Relation of density-density reaction function to compressibility of Fermi liquid and thermodynamic state density. ... Density-density reaction function of free Fermi gas in long-wave limit. ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as