Search Publications
Observed Frequency Variations of Solar p-Mode Travel Times as Evidence for Surface Effects in Sunspot Seismology
Birch, A. C.; Braun, D. C.
Using helioseismic holography, we measure acoustic (p-mode) travel-time perturbations, observed within solar active regions, as functions of frequency and phase speed. We find evidence for a frequency variation, at fixed phase speed, of the travel times that has not previously been reported. This variation is not expected from typical sound-speed …
An ultradeep submillimetre map: beneath the SCUBA confusion limit with lensing and robust source extraction
Smail, I.; Kneib, J. -P.; Ivison, R. J. +7 more
Extracting sources with low signal-to-noise ratio (S/N) from maps with structured background is a non-trivial task which has become important in studying the faint end of the submillimetre (submm) number counts. In this paper, we study the source extraction from submm jiggle-maps from the Submillimetre Common-User Bolometer Array (SCUBA) using the…
Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71 . II. A search for intra-day variability at millimetre wavelengths with the IRAM 30 m telescope
Grewing, M.; Britzen, S.; Wagner, S. J. +12 more
We report on a densely time sampled polarimetric flux density monitoring of the BL Lac object
Magnetopause reconnection rate estimates for Jupiter's magnetosphere based on interplanetary measurements at ~5AU
McComas, D. J.; Nichols, J. D.; Cowley, S. W. H.
We make the first quantitative estimates of the magnetopause reconnection rate at Jupiter using extended in situ data sets, building on simple order of magnitude estimates made some thirty years ago by Brice and Ionannidis (1970) and Kennel and Coroniti (1975, 1977). The jovian low-latitude magnetopause (open flux production) reconnection voltage …
VIMOS-IFU survey of z ~ 0.2 massive galaxy clusters. I. Observations of the strong lensing cluster Abell 2667
Kneib, J. -P.; Jullo, E.; Richard, J. +3 more
We present extensive multi-color imaging and low-resolution VIMOS integral field unit (IFU) spectroscopic observations of the X-ray luminous cluster Abell 2667 (z=0.233). An extremely bright giant gravitational arc (z=1.0334 ± 0.0003) is easily identified as part of a triple image system, and other fainter multiple images are also revealed by the …
The Two-dimensional XMM-Newton Group Survey: z < 0.012 Groups
Mulchaey, John S.; Finoguenov, Alexis; Davis, David S. +1 more
We present the results of the two-dimensional XMM-Newton Group Survey (2dXGS), an archival study of nearby galaxy groups. In this paper we consider 11 nearby systems (z<0.012) in Mulchaey et al., which span a broad range in X-ray luminosity from 1040 to 1043 ergs s-1. We measure the iron abundance and temperatur…
Detection of water ice grains after the DEEP IMPACT onto Comet 9P/Tempel 1
Rodriguez-Pascual, P. M.; Schulz, R.; Lumb, D. +3 more
Context: Icy grains in the inner coma of a comet may play an important role in the energy balance and in the production of certain gas coma species. Their existence has therefore been assumed repeatedly to explain a variety of observed phenomena. However, owing to their extremely short life time no evidence for the presence of icy grains had been …
Low-frequency wave characteristics in the upstream and downstream regime of the terrestrial bow shock
Dandouras, I.; Glassmeier, K. -H.; RèMe, H. +6 more
Collisionless shocks in space are accompanied by the low-frequency waves of the magnetic field both upstream and downstream of the shock. However, characteristics of these waves in the plasma rest frame are poorly understood, since spatial scale such as wavelength is hardly determined using single or at best two spacecraft observations. Taking adv…
An imaging study of the globular cluster systems of NGC 1407 and 1400
Forbes, Duncan A.; Brodie, Jean P.; Strader, Jay +3 more
We present wide-field Keck telescope imaging of the globular cluster (GC) systems around NGC 1407 and 1400 in the Eridanus galaxy cloud. This is complemented by Hubble Space Telescope (HST) images from the Advanced Camera for Surveys of NGC 1407 and Wide Field and Planetary Camera 2 images of NGC 1400. We clearly detect bimodality in the GC colour…
Ultraviolet Properties of Halo Coronal Mass Ejections: Doppler Shifts, Angles, Shocks, and Bulk Morphology
Raymond, J. C.; Ciaravella, A.; Kahler, S. W.
We present UV spectral information for 22 halo or partial halo CMEs observed by UVCS. The CME fronts show broad line profiles, while the line intensities are comparable to the background corona. The Doppler shifts of the front material are generally small, showing that the motion of gas in the fronts is mostly transverse to the line of sight. This…