Search Publications
High-speed coronal rain
Peter, H.; Hansteen, V. H.; De Groof, A. +1 more
At high spatial and temporal resolution, coronal loops are observed to have a highly dynamic nature. Recent observations with SOHO and TRACE frequently show localized brightenings "raining" down towards the solar surface. What is the origin of these features? Here we present for the first time a comparison of observed intensity enhancements from a…
Dust-enshrouded giants in clusters in the Magellanic Clouds
van Loon, J. Th.; Zijlstra, A. A.; Marshall, J. R.
We present the results of an investigation of post-Main Sequence mass loss from stars in clusters in the Magellanic Clouds, based around an imaging survey in the L'-band (3.8 µm) performed with the VLT at ESO. The data are complemented with JHKs (ESO and 2MASS) and mid-IR photometry (TIMMI2 at ESO, ISOCAM on-board ISO, and data fr…
Statistics of Active Region Complexity: A Large-Scale Fractal Dimension Survey
Gallagher, Peter T.; McAteer, R. T. James; Ireland, Jack
A quantification of the magnetic complexity of active regions using a fractal dimension measure is presented. This fully automated approach uses full-disk MDI magnetograms of active regions from a large data set (2742 days of the SOHO mission, 9342 active region images) to compare the calculated fractal dimension of each region to both its Mount W…
The star-forming environment of an ultraluminous X-ray source in NGC4559: an optical study
Cropper, Mark; Soria, Roberto; Wu, Kinwah +2 more
We have studied the candidate optical counterparts and the stellar population in the star-forming complex around the bright ultraluminous X-ray source (ULX) in the western part of the spiral galaxy NGC4559, using the HST Wide Field Planetary Camera 2 (WFPC2), XMM-Newton/Optical Monitor and ground-based data. We find that the ULX is located near a …
An XMM-Newton View of the Soft Gamma Repeater SGR 1806-20: Long-Term Variability in the Pre-Giant Flare Epoch
Tiengo, A.; Götz, D.; Mereghetti, S. +7 more
The low-energy (<10 keV) X-ray emission of the soft gamma repeater SGR 1806-20 has been studied by means of four XMM-Newton observations carried out in the last two years, the latest performed in response to a strong sequence of hard X-ray bursts observed on 2004 October 5. The source was caught in different states of activity; over the 2003-20…
Constraints on z~10 Galaxies from the Deepest Hubble Space Telescope NICMOS Fields
Bouwens, R. J.; Illingworth, G. D.; Thompson, R. I. +1 more
We use all available fields with deep NICMOS imaging to search for J110-dropouts (H160,AB<~28) at z~10. Our primary data set for this search is the two J110+H160 NICMOS fields taken in parallel with the Advanced Camera for Surveys (ACS) Hubble Ultra Deep Field (UDF). The 5 σ limiting magnitudes were ~…
Acceleration and transport of heavy ions at coronal mass ejection-driven shocks
Li, Gang; Zank, G. P.; Rice, W. K. M.
It is now widely accepted that large solar energetic particle (SEP) events are associated with coronal mass ejection (CME)-driven shocks. Here, particles are often accelerated to approximately MeV energies (and perhaps up to GeV energies) at shock waves driven by CMEs. In this paper, on the basis of our earlier work, we present a detailed model wh…
A Detailed Study of Molecular Clouds toward the TeV Gamma-Ray Supernova Remnant G347.3-0.5
Yamaoka, K.; Fukui, Y.; Onishi, T. +4 more
The supernova remnant G347.3-0.5 (J1713.7-3946) is known as one of the unique SNRs that emit TeV γ-rays, as well as nonthermal X-rays. We present a detailed study of molecular gas toward this SNR obtained with the 4 m millimeter and submillimeter telescope NANTEN at an angular resolution of 2.6 arcmin. This study has revealed that several intensit…
On the Origins of Solar EIT Waves
Thompson, B. J.; Laurenza, M.; Cliver, E. W. +1 more
Approximately half of the large-scale coronal waves identified in images obtained by the Extreme-Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory from 1997 March to 1998 June were associated with small solar flares with soft X-ray intensities below C class. The probability of a given flare of this intensity having an a…
A self-consistent model of plasma and neutrals at Saturn: Neutral cloud morphology
Jurac, S.; Richardson, J. D.
We present a model of the plasma and neutral environment that treats plasma and neutrals self-consistently, using Voyager plasma and ultraviolet H observations and Hubble Space Telescope OH measurements as constraints. The neutral distributions are determined with a Monte Carlo model, and the plasma distributions are determined with a diffusive tr…