Search Publications
Flow burst-induced large-scale plasma sheet oscillation
Balogh, A.; Glassmeier, K. -H.; RèMe, H. +7 more
On 12 August 2001 the Cluster spacecraft measured a rapid flux transport event, consisting of a strong perpendicular earthward flow burst combined with a dipolarization of the magnetic field after a strong compression of the magnetotail. Combining the Cluster data with those from ground-based magnetometers, we find that this event is related to pa…
Looking Closely at Medusa: Star-forming Knots at the Center of NGC 4194
Kaiser, M. E.; Weistrop, D.; Eggers, D. +3 more
We report high-resolution ultraviolet and visible-wavelength imaging of the blue compact galaxy NGC 4194 (the Medusa) using the Hubble Space Telescope. A complete sample of 38 UV-bright knots is identified. These knots produce 20% of the ultraviolet emission from the area of the galaxy observed. The bright end of the knot flux distribution can be …
Boron Benchmarks for the Galactic Disk
Cunha, Katia; McGrath, Elizabeth J.; Lambert, David L. +1 more
Sixteen Population I solar-type dwarfs have been selected to ascertain the baseline B abundance in the Galactic disk for a range of a factor of 4 in metallicity: from [Fe/H] of -0.5 to +0.1. All the stars selected are undepleted in Be, which ensures that they have also retained their full initial abundance of B. Evaluation of the trend of B with F…
XMM-Newton observations of the young open cluster Blanco 1. I. X-ray spectroscopy and photometry
Harnden, F. R., Jr.; Micela, G.; Sciortino, S. +2 more
We present an X-ray study of the high metallicity young open cluster Blanco 1 based on XMM-Newton data. X-ray spectroscopy of cluster members is presented for the first time as well as new X-ray distribution functions of late-type stars. We detected all known dF and dG stars in the EPIC field and 80% and 90% of dK and dM stars, respectively. The X…
On the propagation of low-frequency fluctuations in the plasma sheet: 1. Cluster observations and magnetohydrodynamic analysis
Budnik, E.; Balogh, A.; Lucek, E. +6 more
Low-frequency pressure and magnetic oscillations observed by Cluster in the plasma sheet are investigated with the aim of determining if they are magnetohydrodynamic (MHD) eigenmodes. We analyze the plasma sheet crossing occurring on 22 August 2001, as the magnetosphere was first quiet and then active, and compare the observations with theoretical…
On the propagation of low-frequency fluctuations in the plasma sheet: 2. Characterization of the MHD eigenmodes and physical implications
Budnik, E.; Balogh, A.; Lucek, E. +7 more
In a first analysis of the low-frequency fluctuations observed by Cluster during a crossing of the plasma sheet [, 2004], we identify oscillations that likely correspond to MHD eigenmodes. They are intense (10 nT), have a rather short period (20-25 s), have a wavelength of ∼5 Re, and are observed during an active period that follows a s…
Flare-Associated Coronal Mass Ejections with Large Accelerations
Moon, Y. -J.; Dryer, M.; Cho, K. S. +3 more
It is well known that while flare-associated coronal mass ejections (CMEs) show higher speeds and little acceleration in the corona, filament-associated CMEs have lower speeds and large accelerations. In this paper, we examine three flare-associated CMEs with relatively large accelerations as counterexamples of the former tendency. The estimated a…
Solar and solar-wind isotopic compositions
Wimmer-Schweingruber, Robert F.; Wiens, Roger C.; Bochsler, Peter +1 more
With only a few exceptions, the solar photosphere is thought to have retained the mean isotopic composition of the original solar nebula, so that, with some corrections, the photosphere provides a baseline for comparison of all other planetary materials. There are two sources of information on the photospheric isotopic composition: optical observa…
Far-Ultraviolet Observations of Molecular Hydrogen in the Diffuse Interstellar Medium of Starburst Galaxies
Martin, Crystal L.; Aloisi, Alessandra; Hoopes, Charles G. +5 more
The 905-1180 Å spectral range of FUSE includes numerous transitions of molecular hydrogen, making it possible to study H2 in diffuse interstellar environments directly through absorption measurements. We have searched for H2 absorption in five starburst galaxies: NGC 1705, NGC 3310, NGC 4214, M83 (NGC 5236), and NGC 5253. We …
Multiwavelength Analysis of an X1.6 Flare of 2001 October 19
Ding, M. D.; Li, J. P.
An X1.6 two-ribbon flare was observed on 2001 October 19 using the imaging spectrograph at the Solar Tower of Nanjing University. We obtained a time series of two-dimensional Hα line spectra. Combining the observations by the Nobeyama Radioheliograph (NoRH), the Transition Region and Coronal Explorer (TRACE), the Yohkoh soft X-ray telescope (SXT) …