Science Archives Publication System

Instabilities driven by ion shell distributions observed by Cluster in the midaltitude plasma sheet boundary layer

DOI: 10.1029/2005JA011490 Bibcode: 2006JGRA..11110223A

Fazakerley, A. N.; Marchaudon, A.; Cornilleau-Wehrlin, N. +5 more

Cluster observations in the near-Earth plasma sheet boundary layer (PSBL) region have shown the presence of ion shell distributions related to velocity-dispersed ion structures (VDIS) coincident with electrostatic emissions. We have examined ion shell instabilities in the presence of a cold ion and electron background using linear theory and parti…

2006 • Journal of Geophysical Research (Space Physics)

Cluster 12

On the Nature of the Hard X-Ray Source IGR J2018+4043

DOI: 10.1086/508327 Bibcode: 2006ApJ...649L..21B

Kennea, J. A.; Terrier, R.; Rauw, G. +13 more

We found a very likely counterpart to the recently discovered hard X-ray source IGR J2018+4043 in the multiwavelength observations of the source field. The source, originally discovered in the 20-40 keV band, is now confidently detected also in the 40-80 keV band, with a flux of (1.4+/-0.4)×10^-11 ergs cm^-2 s^-1. A 5…

2006 • The Astrophysical Journal

INTEGRAL 12

Energisation of O⁺ and O⁺ ₂ Ions at Mars: An Analysis of a 3-D Quasi-Neutral Hybrid Model Simulation

DOI: 10.1007/s11214-006-9120-z Bibcode: 2006SSRv..126...39K

Kallio, E.; Fedorov, A.; Janhunen, P. +12 more

We have studied the loss of O⁺ and O⁺₂ ions at Mars with a numerical model. In our quasi-neutral hybrid model ions (H⁺, He⁺⁺, O⁺, O⁺₂) are treated as particles while electrons form a massless charge-neutralising fluid. The employed model version does not includ…

2006 • Space Science Reviews

MEx 12

A Blue Straggler Binary with Three Progenitors in the Core of a Globular Cluster?

DOI: 10.1086/500311 Bibcode: 2006ApJ...641..281K

Knigge, C.; Long, K. S.; Gilliland, R. L. +3 more

We show that the X-ray source W31 in the core of the globular cluster 47 Tucanae is physically associated with the bright blue straggler BSS 7. The two sources are astrometrically matched to 0.061", with a chance coincidence probability of less than 1%. We then analyze optical time-series photometry obtained with the Hubble Space Telescope (HST) a…

2006 • The Astrophysical Journal

eHST 12

Short-term changes in the belt/zone structure of Saturn's Southern Hemisphere (1996-2004)

DOI: 10.1051/0004-6361:20065972 Bibcode: 2006A&A...460..641P

Sánchez-Lavega, A.; Pérez-Hoyos, S.; French, R. G.

Aims.The main goal of this paper is to study the reflectivity changes that affect Saturn's global belt/zone pattern on time-scales from weeks to a few months, and to determine their frequency and intensity, as well as the variations of the vertical cloud structure that cause such changes.
Methods: .We have used 177 images from Hubble Space Tel…

2006 • Astronomy and Astrophysics

eHST 12

The dark clump near Abell 1942: dark matter halo or statistical fluke?

DOI: 10.1051/0004-6361:20052733 Bibcode: 2006A&A...454...37V

Castander, F. J.; von der Linden, A.; Schneider, P. +1 more

Using HST WFPC2 mosaic imaging, deep Chandra observations, and the

original CFHT imaging, we investigate the case for the dark clump candidate originally presented by (Erben et al. 2000, A&A, 355, 23). We show that the original detection is well reproducible in the CFHT data, and can confirm the presence of an alignment signal at the dark…

2006 • Astronomy and Astrophysics

eHST 12

X-Ray Pulsations in the Supersoft X-Ray Binary CAL 83

DOI: 10.1086/498271 Bibcode: 2006AJ....131..600S

Cowley, A. P.; Schmidtke, P. C.

Chandra and XMM-Newton X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations of the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

2006 • The Astronomical Journal

XMM-Newton 12

New upper limits for hydrogen halides on Saturn derived from Cassini-CIRS data

DOI: 10.1016/j.icarus.2006.07.011 Bibcode: 2006Icar..185..466T

Fletcher, L. N.; Irwin, P. G. J.; Teanby, N. A. +2 more

Far infrared spectra (10-600 cm ^-1) from Cassini's Composite InfraRed Spectrometer (CIRS) were used to determine improved upper limits of hydrogen halides HF, HCl, HBr, and HI in Saturn's atmosphere. Three observations, comprising a total of 3088 spectra, gave 3 σ upper limits on HF, HCl, HBr, and HI volume mole fractions of 8.0×10, 6.7…

2006 • Icarus

Cassini 12

Mars 1064 nm spectral radiance measurements determined from the receiver noise response of the Mars Orbiter Laser Altimeter

DOI: 10.1364/AO.45.003960 Bibcode: 2006ApOpt..45.3960S

Zuber, Maria T.; Sun, Xiaoli; Neumann, Gregory A. +1 more

A technique was developed to compute the radiance of the scene viewed by the optical receiver of the Mars Orbiter Laser Altimeter. The technique used the detection threshold and the false detection rate of the receiver to provide a passive radiometry measurement of Mars at the 1064 nm wavelength over a 2 nm bandwidth and subkilometer spatial resol…

2006 • Applied Optics

eHST 12

EIT and TRACE responses to flare plasma

DOI: 10.1051/0004-6361:20066481 Bibcode: 2006A&A...460L..53T

Mason, H. E.; Del Zanna, G.; Tripathi, D. +1 more

Aims.To understand the contribution of active region and flare plasmas to the λ195 channels of SOHO/EIT (Extreme-ultraviolet Imaging Telescope) and TRACE (Transition Region and Coronal Explorer).
Methods: .We have analysed an M8 flare simultaneously observed by the Coronal Diagnostic Spectrometer (CDS), EIT, TRACE and RHESSI. We obtained synth…

2006 • Astronomy and Astrophysics

SOHO 11