Search Publications
Fast coronal mass ejection environments and the production of solar energetic particle events
Vourlidas, A.; Kahler, S. W.
The search continues for coronal environmental factors that determine whether a fast coronal mass ejection (CME) results in a solar energetic particle (SEP) event at 1 AU. From a plot of peak 20 MeV SEP intensities versus associated CME speeds we select for comparison two groups of fast, wide, western hemisphere CMEs observed with the LASCO corona…
Reconstruction of the magnetotail current sheet structure using multi-point Cluster measurements
Balogh, A.; Zhang, T. L.; Nakamura, R. +7 more
In this paper we analyze the vertical structure of the magnetotail current sheet for a few intervals during which Cluster repeatedly crosses the neutral sheet due to fast flapping motion. They include fast flows with episodes of flow reversals. The curl, gradient and divergence of the magnetic field are estimated using linear gradient/curl estimat…
Detection of Water in the Shocked Gas Associated with IC 443: Constraints on Shock Models
Wang, Z.; Bergin, E. A.; Melnick, G. J. +5 more
We have used the Submillimeter Wave Astronomy Satellite (SWAS) to observe the ground-state 110-->101 transition of ortho-H2O at 557 GHz in three of the shocked molecular clumps associated with the supernova remnant IC 443. We also observed simultaneously the 487 GHz line (3,1-->3,2) of O2, the 492 …
HST/ACS Lyman α imaging of the nearby starburst ESO 338-IG04
Östlin, G.; Hayes, M.; Mas-Hesse, J. M. +3 more
ESO 338-IG04 (Tololo 1924-416) is a well-known, luminous (MV = -19.3) Blue Compact Galaxy in the local universe. Its complex morphology indicates a recent merger and/or close interaction, and it contains a central young starburst with compact star clusters of ages ≲ 40 Myr. The galaxy was imaged using the Advanced Camera for Surveys onb…
The Hubble Space Telescope View of LINER Nuclei: Evidence for a Dual Population?
Chiaberge, Marco; Capetti, Alessandro; Macchetto, F. Duccio
We study a complete, distance-limited sample of 25 LINERs, 21 of which have been imaged with the Hubble Space Telescope. In nine objects we detect an unresolved nucleus. To study their physical properties, we compare the radio and optical properties of the nuclei of LINERs with those of other samples of local active galactic nuclei (AGNs), namely,…
First current density measurements in the ring current region using simultaneous multi-spacecraft CLUSTER-FGM data
Balogh, A.; Dandouras, I.; Lucek, E. +7 more
The inner magnetosphere's current mapping is one of the key elements for current loop closure inside the entire magnetosphere. A method for directly computing the current is the multi-spacecraft curlometer technique, which is based on the application of Maxwell-Ampère's law. This requires the use of four-point magnetic field high resolution measur…
The first detection of [OIII] emission from high-redshift damped Lyman-α galaxies
Fall, S. M.; Møller, P.; Weatherley, S. J. +3 more
We present the detection of [OIII] emission lines from the galaxies responsible for two high-redshift z > 1.75 damped Lyman-α (DLA) absorption lines. We find two sources of [OIII] emission corresponding to the z= 1.92 DLA absorber towards the quasar Q2206-1958, and we also detect [OIII] emission from the galaxy responsible for the z= 3.10 DLA a…
Repeated X-Ray Flaring Activity in Sagittarius A*
Grosso, N.; Porquet, D.; Ferrando, P. +5 more
Investigating the spectral and temporal characteristics of the X-rays coming from Sagittarius A* (Sgr A*) is essential to our development of a more complete understanding of the emission mechanisms in this supermassive black hole located at the center of our Galaxy. Several X-ray flares with varying durations and spectral features have already bee…
Oxygen-rich AGB stars with optically thin dust envelopes
Heras, A. M.; Hony, S.
The dust composition and dynamics of the circumstellar envelopes of oxygen-rich AGB stars with low mass-loss rates (5 × 10-8-10-5 M⊙ yr-1) have been investigated. We have analyzed the ISO-SWS spectra of twenty-eight oxygen-rich AGB stars with optically thin shells, and modelled the observations with the …
The Loopy Ultraviolet Line Profiles of RU Lupi: Accretion, Outflows, and Fluorescence
Herczeg, Gregory J.; Valenti, Jeff A.; Brown, Alexander +6 more
We present far-ultraviolet (FUV) spectra of the classical T Tauri star RU Lup covering the 912-1710 Å spectral range, as observed by the Hubble Space Telescope STIS and the Far Ultraviolet Spectroscopic Explorer satellite. We use these spectra, which are rich in emission and absorption lines, to probe both the accreting and outflowing gas. Absorpt…