Search Publications
An Evolutionary Turbulent Model of Saturn's Subnebula: Implications for the Origin of the Atmosphere of Titan
Mousis, Olivier; Gautier, Daniel; Bockelée-Morvan, Dominique
We have elaborated an evolutionary turbulent model of the subnebula of Saturn derived from that of Dubrulle (1993, Icarus106, 59-76) for the solar nebula, which is valid for a geometrically thin disk. We demonstrate that if carbon and nitrogen were in the form of CO and N 2, respectively, in the early subnebula, these molecules were not…
Active-Region Filaments and X-ray Sigmoids
Pevtsov, Alexei A.
We use Yohkoh soft X-ray telescope data and Hα full-disk observations to study the evolution of chromospheric filaments and coronal sigmoids in 6 active regions in association with coronal mass ejections (CMEs). In two cases, CMEs are directly observed by the SOHO/LASCO C2 coronagraph. In four cases, other observations (magnetic clouds, geomagneti…
Simultaneous Observation of a Moreton Wave on 1997 November 3 in Hα and Soft X-Rays
Narukage, N.; Hudson, H. S.; Shibata, K. +4 more
We report the observation of a Moreton wave in Hα (line center and +/-0.8 Å) with the Flare Monitoring Telescope at the Hida Observatory of Kyoto University at 4:36-4:41 UT on 1997 November 3. The same region (NOAA Active Region 8100) was simultaneously observed in soft X-rays with the soft X-ray telescope on board Yohkoh, and a wavelike disturban…
Are Homologous Flare-Coronal Mass Ejection Events Triggered by Moving Magnetic Features?
Zhang, Jun; Wang, Jingxiu
Coronal mass ejections (CMEs) often present destabilization and eruption of a global (or large-scale) magnetic structure in the solar atmosphere. Furthermore, the Earth-directed CMEs are the primary driver of the disastrous space weather. Here we report on five homologous CMEs. They initiated in the early phase of five homologous X-class flares se…
Chandra Study of Young Stellar Objects in the NGC 1333 Star-forming Cloud
Lada, Charles J.; Bally, John; Feigelson, Eric D. +3 more
NGC 1333, a highly active star formation region within the Perseus molecular cloud complex, has been observed with the ACIS-I detector on board the Chandra X-Ray Observatory. In our image with a sensitivity limit of ~1028 ergs s-1, we detect 127 X-ray sources, most with subarcsecond positional accuracy. While 32 of these sour…
Hidden star-formation in the cluster of galaxies Abell 1689
Elbaz, D.; Cesarsky, C.; Duc, P. -A. +6 more
At a redshift of 0.18, Abell 1689 is so far the most distant cluster of galaxies for which substantial mid-infrared (MIR) data have been published. Its mapping with the ISOCAM camera onboard the ISO satellite allowed the detection of 30 cluster members at 6.75 micron (LW2 filter) and 16 cluster members at 15 micron (LW3 filter) within a clustercen…
Deuterium Abundance toward G191-B2B: Results from the FUSE Mission
Kruk, J. W.; Sonneborn, G.; Moos, H. W. +19 more
High-resolution spectra of the hot white dwarf G191-B2B, covering the wavelength region 905-1187 Å, were obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). These data were used in conjunction with existing high-resolution Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) observations to evaluate the total H I, D I, O…
Transient aurora on Jupiter from injections of magnetospheric electrons
Clarke, J. T.; Waite, J. H.; Mauk, B. H. +3 more
Energetic electrons and ions that are trapped in Earth's magnetosphere can suddenly be accelerated towards the planet. Some dynamic features of Earth's aurora (the northern and southern lights) are created by the fraction of these injected particles that travels along magnetic field lines and hits the upper atmosphere. Jupiter's aurora appears sim…
Classification of 2.4-45.2 Micron Spectra from the Infrared Space Observatory Short Wavelength Spectrometer
Sloan, G. C.; Kraemer, Kathleen E.; Price, Stephan D. +1 more
The Infrared Space Observatory observed over 900 objects with the Short Wavelength Spectrometer in full-grating scan mode (2.4-45.2 µm). We have developed a comprehensive system of spectral classification using these data. Sources are assigned to groups based on the overall shape of the spectral energy distribution (SED). The groups include …
Hubble Space Telescope Evidence for an Intermediate-Mass Black Hole in the Globular Cluster M15. I. STIS Spectroscopy and WFPC2 Photometry
Gerssen, Joris; van der Marel, Roeland P.; Gebhardt, Karl +2 more
In this series of two papers, we describe a project with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) to measure the line-of-sight velocities of stars in the central few arcseconds of the dense globular cluster M15. The main goal of this project is to search for the possible presence of an intermediate-mass c…