Search Publications
A Comparison of Surface Brightness Profiles for Ultracompact Dwarfs and Dwarf Elliptical Nuclei: Implications for the ``Threshing'' Scenario
Drinkwater, M. J.; De Propris, R.; Jones, J. B. +4 more
Using imaging from the Hubble Space Telescope, we derive surface brightness profiles for ultracompact dwarfs in the Fornax Cluster and for the nuclei of dwarf elliptical galaxies in the Virgo Cluster. Ultracompact dwarfs are more extended and have higher surface brightnesses than typical dwarf nuclei, while the luminosities, colors, and sizes of t…
Multi-spacecraft determination of wave characteristics near the proton gyrofrequency in high-altitude cusp
Wahlund, J. -E.; André, M.; Stenberg, G. +11 more
We present a detailed study of waves with frequencies near the proton gyrofrequency in the high-altitude cusp for northward IMF as observed by the Cluster spacecraft. Waves in this regime can be important for energization of ions and electrons and for energy transfer between different plasma populations. These waves are present in the entire cusp …
Fiber bursts as 3D coronal magnetic field probe in postflare loops
Mann, G.; Aurass, H.; Rausche, G. +1 more
Fiber bursts appear in some complex solar radio bursts as a continuum fine structure in the frequency range of 150\cdots3000 MHz. We present and test a new method to use fiber bursts as a probe of the magnetic field strength and the 3D field structure in postflare loops. Thereby we assume that fiber bursts are driven by whistler waves ascending in…
Planetary Fourier spectrometer data analysis: Fast radiative transfer models
Grassi, D.; Ignatiev, N. I.; Zasova, L. V.
We present fast algorithms used in IKI and IFSI for the analysis of the Martian spectra measured in the Planetary Fourier Spectrometer (PFS) experiment onboard Mars Express orbiter. The first algorithm is based on a new very general and precise approach applicable to planetary atmospheres with quite arbitrary absorption and scattering properties. …
On the evolutionary status of early-type galaxies in clusters at z~ 0.2 - I. The Fundamental Plane
Smail, Ian; Davies, Roger L.; Bower, Richard G. +2 more
We investigate a spectroscopic sample of 48 early-type galaxies in the rich cluster Abell 2390 at z= 0.23 and 48 early-type galaxies from a previously published survey of Abell 2218 at z= 0.18. The spectroscopic data of A2390 are based on multi-object spectroscopy using the multi-object spectrograph for Calar Alto at the 3.5-m telescope on Calar A…
On the origin of microwave zebra pattern
Kuznetsov, A. A.; Yan, Yihua; Altyntsev, A. T. +2 more
The results of the first observations of a zebra pattern at frequencies around5.6GHz are presented. The fine structures in the emission spectrum were recorded simultaneously by the Siberian Solar Radiotelescope and the spectropolarimeters of the National Astronomical Observatories, which allowed us to study the presented event with high spatial, t…
Solar control on Jupiter's equatorial X-ray emissions: 26-29 November 2003 XMM-Newton observation
Branduardi-Raymont, G.; Soria, R.; Waite, J. H. +6 more
During Nov. 26-29, 2003 XMM-Newton observed soft (0.2-2 keV) X-ray emission from Jupiter for 69 hours. The low-latitude X-ray disk emission of Jupiter is observed to be almost uniform in intensity with brightness that is consistent with a solar-photon driven process. The simultaneous light curves of Jovian equatorial X rays and solar X rays (measu…
Cassini Discovers a Kinematic Spiral Ring Around Saturn
Charnoz, S.; Porco, C. C.; Déau, E. +4 more
Since the time of the Voyager flybys of Saturn in 1980-1981, Saturn's eccentric F ring has been known to be accompanied on either side by faint strands of material. New Cassini observations show that these strands, initially interpreted as concentric ring segments, are in fact connected and form a single one-arm trailing spiral winding at least th…
Characteristic Times of Gradual Solar Energetic Particle Events and Their Dependence on Associated Coronal Mass Ejection Properties
Kahler, S. W.
We use 20 MeV proton intensities from the EPACT instrument on Wind and coronal mass ejections (CMEs) from the LASCO coronagraph on SOHO observed during 1998-2002 to statistically determine three characteristic times of gradual solar energetic particle (SEP) events as functions of solar source longitude: (1) TO, the time from associated …
Luminosity Functions of the Galaxy Cluster MS 1054-0321 at z=0.83 based on ACS Photometry
Goto, Tomotsugu; Ford, H. C.; Demarco, R. +41 more
We present new measurements of the galaxy luminosity function (LF) and its dependence on local galaxy density, color, morphology, and clustocentric radius for the massive z=0.83 cluster MS 1054-0321. Our analyses are based on imaging performed with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST) in the F606W, F775W,…