... 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. | ...

... Home . ... Data . Archives . ... Calibration . ... Following the installation of a new delivery of WFPC2 flat fields to the archive and pipeline databases, it has been discovered that a small number of these flat fields were incorrectly normalized. ... Note that when the science images above, or any science image, are retrieved from the HST archive using OTFR (On The Fly Reprocessing), the proper calibration files, including the correctly normalized flats listed above, will be applied to the data. ...

... The Eskimo Nebula from Hubble . ... In 2000, the Hubble Space Telescope imaged the Eskimo Nebula. From space, the nebula displays gas clouds so complex they are not fully understood. ... Bright Galaxy M81 . ... NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. ... Sprawling spiral arms dotted with bright red emission nebulas highlight this new and detailed image of nearby spiral galaxy NGC 2403. ...

... Other Characteristics of the Sun: Variability of Rotation, Magnetism, Chemical Structure, Planetary System. ... Methods of Solar Magnetic Fields Measuring: Visual, Photografic, Photoelectric. ... Empiric Datas of Magnetic Fields in Photosphere, Chromosphere and Corona. ... Characteristics of Magnetic Field in Balanced Force Tubes by Potential and Forceless Field. ... Phenomenons in Active Region (Magnetic Field, Spots, Torches, Solar Prominences, Flares, Discharges. ... Magnetic Fields in Flares. ...

... Astronomers of the SAO together with an international group of scientists have proposed an explanation to the long-standing mystery of why magnetic fields are more common amongst cool white dwarf stars than amongst young and hotter ones. ... As the result magnetic white dwarfs demonstrate excess in their frequencies in the temperature range below 14000K. The authors also show that the strongly magnetic white dwarfs are of the oldest stars of the Galaxy originated from intermediate-mass relic stars. ...

SAS home . ... EPIC background spectra are normally extracted from regions of the observation field-of-view, once "contamination" due to individual discrete celestial sources has been removed. ... In order to cope with this situation, blank sky event lists can be downloaded from the XMM-Newton Science Operations Center web site. ... It is in principle possible as well to extract background spectra from blank field event lists, if the spectrum accumulation regions are defined in sky coordinates. ...

... Files in red?history) . ... Field Lines . ... EM Waves . ... Magnetic field lines similarly describe the structure of magnetic fields in three dimensions.They are defined as follows. ... Maxwell Most scientists nowadays view field lines as intangible abstractions, useful only for describing magnetic fields. ... Maxwell also showed (perhaps his greatest achievement) that an "electromagnetic wave" was possible, a rapid interplay of electric and magnetic fields spreading with the velocity of light. ...

... Files in red?history) . ... Field Lines . ... EM Waves . ... Magnetic field lines similarly describe the structure of magnetic fields in three dimensions.They are defined as follows. ... Maxwell Most scientists nowadays view field lines as intangible abstractions, useful only for describing magnetic fields. ... Maxwell also showed (perhaps his greatest achievement) that an "electromagnetic wave" was possible, a rapid interplay of electric and magnetic fields spreading with the velocity of light. ...

. Subdwarfs . Metal deficient red giants in galactic field . Red horizontal branch stars . Blue horizontal branch stars . Extended horizontal branch stars . Stars inside globular clusters . W Vir type stars . IRAS-sources identified with peculiar supergiants . RCrB type stars . Sakurai's object . peculiar supergiant FG Sge .

... Science . ... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: Magnetic fields and interaction in binary systems . ... Data Handling and Products . ... ESO Data . ... Close binary systems display signs of interaction between their stellar components, through tidal deformation, interaction of stellar winds. ... The student project will involve analysing fundamental properties of binaries and analysing their magnetic fields. ...

... The lamps used for flat fields have an uneven spectral emissivity. ... Therefore a direct flat-fielding, i.e. , division by the original dark subtracted flat-field, produces spectra which are artificially enhanced in some parts and depressed in others. ... This command first averages the original image along the slit (assumed to be along the Y-axis) and fits the resulting one-dimensional image by a polynomial of specified degree. ...

Next: Evolution of Magnetic Rotators Up: ``Ecology'' of Magnetic Rotators Previous: The equilibrium period . The evolution of NS in binaries must be studied in conjunction with the evolution of normal stars. ... Figure: Tracks of NS on the period ( p ) - gravimagnetic parameter ( Y ) diagram: track of a single NS (vertical line) and of a NS in a binary system (looped line). ... Another version of the evolutionary track of a NS formed in the process of mass exchange within a binary system is: . ...

... I normally begin by asking the class what they think would be different if the Moon didn't exist, or if the Sun were closer to Earth, or if a star exploded nearby. ... The winds would be much stronger. ... In using what-if questions in the classroom, it is worth bearing in mind that students extrapolating the effects of new scenarios will encounter two different situations: direct changes to the new version of Earth and indirect changes resulting from the direct changes. ...

... Tonight's Sky . ... Observing . ... Sky this Month . ... Star Atlas . ... stars . ... Observing Podcasts . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... How do neutron stars generate steady magnetic fields? ... How can a neutron star exist if those neutrons are just going to pieces? Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

P. Frisch - Warm partially ionized interstellar gas at the Sun . ... W. M. Goss - Time variations in small-scale galactic HI structure toward 3C138 . S. Stanimirovic - Does tiny-scale atomic structure exist in the ISM? ... T. Bania - The distance to molecular clouds via HI self-absorption . ... C. Heiles - Arecibo Millennium Survey statistics of magnetic field, column density and turbulence in the CNM . R. Crutcher - Magnetic fields in molecular clouds . ...

... Theoretical department of ISSP RAS . ... Pis'ma v ZhETF, 69 , 543, 1999; V.E.Bisti , Pis'ma v ZhETF, 73 , 25, 2001 ). (ii) Collective intrasubband charge density excitations are investigated in double GaAs/AlGaAs quantum wells in external parallel magnetic field. ... Goldstone mode relaxation in a quantum Hall ferromagnet . ... The considered system is a Quantum Hall Ferromagnet possessing "classical" spin S 0 ~N j /2 (N j being the number of magnetic flux quanta, S 0 || ... Spin biexciton. ...

... 2006 July 10 . Dark Sun Sizzling . ... Explanation: Is this our Sun? ... Unpredictably, regions of strong and tangled magnetic fields arise, causing sunspots and bright active regions . ... These active regions channel gas along magnetic loops , usually falling back but sometimes escaping into the solar corona or out into space as the solar wind . ... Since only active regions emit significant amounts of energetic ultraviolet light, most of the Sun appears dark. ... About APOD | ...

Unno, W. Line Formation of a Normal Zeeman Triplet http://adsabs.harvard.edu/abs/1956PASJ.. ... 108U Moe, Olav Kjeldseth A Generalized Theory for Line Formation in a Homogeneous Magnetic Field http://adsabs.harvard.edu/abs/1968SoPh.. ... 24S Landi Degl'Innocenti, Egidio; Landi Degl'Innocenti, Maurizio Quantum Theory of Line Formation in a Magnetic Field http://adsabs.harvard.edu/abs/1972SoPh.. ... 235H Sazonov, V. N. Polarization in Zeeman-split absorption lines http://adsabs.harvard.edu/abs/1975SvA.. ...

... Fundamental core Alfven mode ~20Hz Fundamental crust shear mode ~10 ­ 40 Hz Strong coupling leads to non-trivial dynamics. ... Initial crustal displacements decay in <second What happens then? crust · Global modes are strongly damped when inside Alfven continuum (L.06,07, Gruzinov 08) · cf. ... Crustal modes Alfven continuum (edge and gap modes) Tangling: effective shear modulus, discrete modes' grid Mass loading in the core (superfluidity, proton fraction) Transient QPOs Successes: 1. ...

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