Search Publications

Performance of high-density cast silicon carbide in the extreme ultraviolet

Keski-Kuha, Ritva A. M.; Fleetwood, Charles M.; Robichaud, Joseph

A Compact Circumstellar Dust Envelope of an Evolved AGB Star IRC-10529

Izumiura, H.; Hashimoto, O.

We have made far-infrared mapping observations around a heavily mass losing evolved star IRC-10529 with ISO. It is found that IRC-10529 shows a very compact circumstellar dust envelope in the 60 and 90 µm images obtained by ISOPHOT. Such a small size of the circumstellar dust envelope indicates very short history of the present strong mass loss. I…

Near Infrared Imaging of the Proposed z=2 Cluster Behind CL 0939+4713 (Abell 851)

Hutchings, J. B.; Davidge, T. J.

We have obtained deep J and K' images of a 90 arcsec square field containing the z=2.0 QSO that is viewed through the z=0.4 rich cluster A851. Brightnesses of individual galaxies are measured from these data, and archival F702W WFPC2 images from HST. The results are used to construct 2-colour diagrams, colour-magnitude diagrams, and luminosity fun…

Emission Lines from Companion Galaxies of QSOs

Gnedin, Oleg Y.

Anticipating new spectroscopic studies of quasar companions, we calculate expected emission-line spectra for the companion galaxies. Under the assumption of isotropic photoionizing radiation, we predict equivalent widths for Hα, Hβ, [O III] λ5007, [O II] λ3727, [Ne III] λ3869, and Mg II λ2798 lines. We consider six quasars, two of which (PKS 2135-…

The de-censoring of the faint stars in TYCHO photometry.

Grenon, M.; Hog, E.; Halbwachs, J. L. +3 more

The Tycho catalogue provides astrometric and photometric data for more than 1 million stars. The derivation of the mean magnitudes of stars fainter than about 8mag required a dedicated treatment, in order to take into account the observations that were too faint for providing a measurable signal. This treatment, called "de-censoring", is based on …

ERNE observations of energetic particle fluxes

Laitinen, T.; Vainio, R.; Valtonen, E. +7 more

The observations of the ERNE instrument on-board the SOHO spacecraft are analysed. The main period under study is from the beginning of May till mid-October 1996. Only very small energetic particle events were observed. A comparison of the ERNE measurements with energetic particle observations during the two previous solar minima indicates that th…

Clumpy Structure and Polarization in NGC 1068

Kishimoto, M.

The polarization map from the HST archival data of the imaging polarimetry for NGC 1068 is analyzed. In the HST images, the central few arcsecond region seems to consist of several clumps, and if we extract the polarization of the clumps separately, the viewing angle of each clump can be determined. This enables us to have a three-dimensional view…

Evolution of Cosmic Ray Electron Spectra above 350 MeV along the Ulysses Trajectory

Kunow, H.; Bothmer, V.; Wibberenz, G. +6 more

Magnetic mapping of auroral signatures of comet SL9 in the Jovian magnetosphere

Dunlop, M.; Prangé, R.; Maurice, S. +2 more

The electrodynamic interaction of comet Shoemaker-Levy 9 (SL9) with the Jovian magnetosphere gave rise to the detection of several unique phenomena in the UV, X-ray and radio wavelength ranges. Among them, the detection of an unusual FUV bright spot in Hubble Space Telescope images of the southern polar cap on July 20, just before P2 collision, ma…

Three-dimensional nature of interaction regions: Pioneer, Voyager, and Ulysses solar cycle variations from 1 to 5 AU

Smith, Edward J.; Américo González-Esparza, J.