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Molecular hydrogen emission from protoplanetary disks
Nomura, H.; Millar, T. J.
We have modeled self-consistently the density and temperature profiles of gas and dust in protoplanetary disks, taking into account irradiation from a central star. Making use of this physical structure, we have calculated the level populations of molecular hydrogen and the line emission from the disks. As a result, we can reproduce the observed s…
Abundance Profiles and Kinematics of Damped Lyα Absorbing Galaxies at z < 0.651,
Chen, Hsiao-Wen; Rauch, Michael; Kennicutt, Robert C., Jr.
We present a spectroscopic study of six damped Lyα absorption (DLA) systems at z<0.65, based on moderate- to high-resolution spectra of the galaxies responsible for the absorbers. Combining known metallicity measurements of the absorbers with known optical properties of the absorbing galaxies, we confirm that the low metal content of the DLA po…
Chandra Detection of the First X-Ray Forest along the Line of Sight To Markarian 421
Elvis, Martin; Marshall, Herman; Nicastro, Fabrizio +7 more
We present the first >=3.5 (conservative) or >=5.8 σ (sum-of-lines significance) detection of two warm-hot intergalactic medium (WHIM) filaments at z>0, which we find along the line of sight to the blazar Mrk 421. These systems are detected through highly ionized resonant metal absorption in high-quality Chandra ACIS and HRC Low Energy Tr…
Absolute dimensions of detached eclipsing binaries - I. The metallic-lined system WW Aurigae
Maxted, P. F. L.; Southworth, J.; Claret, A. +2 more
WW Aurigae is a detached eclipsing binary composed of two metallic-lined A-type stars orbiting each other every 2.5 d. We have determined the masses and radii of both components to accuracies of 0.4 and 0.6 per cent, respectively. From a cross-correlation analysis of high-resolution spectra we find masses of 1.964 +/- 0.007 Msolar for t…
Propagation of the 12 May 1997 interplanetary coronal mass ejection in evolving solar wind structures
Arge, C. N.; Odstrcil, D.; Pizzo, V. J.
Recently, we simulated the 12 May 1997 coronal mass ejection (CME) event with a numerical three-dimensional magnetohydrodynamic model (Odstrcil et al., 2004), in which the background solar wind was determined from the Science Applications International Corporation (SAIC) coronal model (Riley et al., 2001) and the transient disturbance was determin…
Morphological differences between Saturn's ultraviolet aurorae and those of Earth and Jupiter
Kim, J.; Hill, T.; Crary, F. +10 more
It has often been stated that Saturn's magnetosphere and aurorae are intermediate between those of Earth, where the dominant processes are solar wind driven, and those of Jupiter, where processes are driven by a large source of internal plasma. But this view is based on information about Saturn that is far inferior to what is now available. Here w…
Temperature and entropy profiles of nearby cooling flow clusters observed with XMM-Newton
Kaastra, J. S.; Tamura, T.; Piffaretti, R. +1 more
We investigate temperature and entropy profiles of 13 nearby cooling flow clusters observed with the EPIC cameras of XMM-Newton. When normalized and scaled by the virial radius the temperature profiles turn out to be remarkably similar. At large radii the temperature profiles show a clear decline starting from a break radius at ~0.1 rvir
Confirmation of Errors in Hipparcos Parallaxes from Hubble Space Telescope Fine Guidance Sensor Astrometry of the Pleiades
Soderblom, David R.; Benedict, G. Fritz; McArthur, Barbara +4 more
We present absolute trigonometric parallaxes and relative proper motions for three members of the Pleiades, obtained with the Hubble Space Telescope's Fine Guidance Sensor 1r, a white-light interferometer. We estimate spectral types and luminosity classes of the stars comprising the astrometric reference frame from R~2000 spectra, VJHK photometry,…
Evolution and characteristics of global Pc5 ULF waves during a high solar wind speed interval
Balogh, A.; Lavraud, B.; Wild, J. A. +9 more
We present an interval of extremely long-lasting narrow-band Pc5 pulsations during the recovery phase of a large geomagnetic storm. These pulsations occurred continuously for many hours and were observed throughout the magnetosphere and in the dusk-sector ionosphere. The subject of this paper is the favorable radial alignment of the Cluster, Polar…
Global solar Doppler velocity determination with the GOLF/SoHO instrument
Jiménez-Reyes, S. J.; García, R. A.; Pallé, P. L. +10 more
The Global Oscillation at Low Frequencies (GOLF) experiment is a resonant scattering spectrophotometer on board the Solar and Heliospheric Observatory (SoHO) mission, originally designed to measure the disk-integrated solar oscillations of the Sun. This instrument was designed in a relative photometric mode involving both wings of the neutral sodi…