Search Publications
Atomic Data and Emission-Line Intensities for Ca VII
Bhatia, A. K.; Landi, E.
In the present work we calculate energy levels, transition probabilities, and electron-ion collisional excitation rates for the 3s23p2, 3s3p3, and 3s23p3d configurations of the silicon-like ion Ca VII. The total number of intermediate coupling levels considered is 27. Collision strengths are calculated a…
Strong interplanetary field enhancements at Ulysses—evidence of dust trails' interaction with the solar wind?
Balogh, André; Jones, Geraint H.; MacDowall, Robert J. +1 more
Interplanetary field enhancements were first discovered in the vicinity of Venus. These events are characterised by an increase in the magnitude of the heliospheric magnetic field with a near-symmetrical, sometimes thorn-shaped profile, and last from minutes to hours. Surveys of the events near Venus and Earth indicated clustering of the events in…
On ion-cyclotron-resonance heating of the corona and solar wind
Tu, C. -Y.; Marsch, E.; Vocks, C.
This paper concisely summarizes and critically reviews recent work by the authors on models of the heating of the solar corona by resonance of ions with high-frequency waves (up to the proton cyclotron frequency). The quasi-linear theory of pitch angle diffusion is presented in connection with relevant solar wind proton observations. Hybrid fluid-…
The Orion nebula (M42) Herbig-Haro object, HH 201, within the tip of a molecular finger
Redman, M. P.; Meaburn, J.; Graham, M. F.
The most prominent Herbig-Haro (HH) object, HH 201, in the Orion nebula is investigated using optical spectroscopy along with optical and infrared images. An infrared Subaru H2v= 1-0 S(1) image of the region surrounding the optical line emission of HH 201 has yielded the discovery of a faint H2 finger associated with HH 201. …
Mars atmospheric water vapor abundance: 1996-1997
Doose, L. R.; Hunten, D. M.; Sprague, A. L. +1 more
Measurements of martian atmospheric water vapor made throughout Ls = 18.0°-146.4° (October 3, 1996-July 12, 1997) show changes in Mars humidity on hourly, daily, and seasonal time scales. Because our observing program during the 1996-1997 Mars apparition did not include concomitant measurement of nearby CO 2 bands, high north…
Interaction of an Erupting Filament with the Ambient Magnetoplasma and Escape of Electron Beams
Vršnak, Bojan; Warmuth, Alexander; Otruba, Wolfgang +2 more
A huge filament eruption of 12 September 2000 associated with a two-ribbon spotless flare is described. During the acceleration phase the shape of the filament changed, and signatures of topological restructuring of large-scale coronal magnetic fields were inferred by tracking changes of nearby coronal holes. At the same time electron beams associ…
High Spectral Resolution H2 Measurements of Herbig-Haro Objects 38, 46/47, and 120
Schwartz, Richard D.; Greene, Thomas P.
We report high spectral resolution (R~=20,000) measurements of the H2 1-0S(1) line in Herbig-Haro objects 38, 46/47, and 120. The long-slit spectra reveal complex velocity structure with evidence for bow-shock structures, as well as prompt entrainment and shock heating of ambient molecular gas. Individual knots within HH 38 show distinc…
Variations in Oscillation Frequencies From Minimum to Maximum of Solar Activity
Jain, Kiran; Bhatnagar, A.
The temporal variation in intermediate-degree-mode frequencies is analysed using helioseismic data which cover the minimum to the maximum phase of the current solar cycle. To study the variation in detail, the measured frequency shifts of f and p modes are decomposed into two components, viz., oscillatory and non-oscillatory. The f-mode frequencie…
Photospheric flows measured with TRACE II. Network formation
Roudier, T.; Krijger, J. M.
We analyse a 7 d (167 h) sequence of TRACE white-light images with 1 arcsec angular resolution taken at 1 min cadence. The TRACE resolution and the fast cadence allows us to produce maps of the horizontal flow fields with high angular (1 arcsec) and temporal resolution (5 min). The field of view of 128arcsec x 128arcsec (~93 Mm x 93 Mm) covers app…
The corona of V390 Aurigae (HD 33798)
Gondoin, P.
V390 Aurigae (HD 33798) is a rapidly rotating, lithium rich, late-type giant whose distinctive characteristics include a high X-ray luminosity observed by the XMM-Newton space observatory. Series of lines of highly ionized Fe and several Lyman lines of hydrogen-like ions and triplet lines of helium-like ions are visible in the reflection grating s…