Search Publications
Modulation of galactic cosmic rays at solar maximum: Observations
Zhang, Ming
The spectra of galactic cosmic rays observed anywhere inside the heliosphere are modulated by the sun because the charged particles must fight their ways inward against the radially expanding solar wind. In the past half a century, galactic cosmic ray fluxes at Earth were continuously monitored by neutron monitors on the ground and instruments on …
Observations of auroral broadband emissions by CLUSTER
Balogh, A.; Wahlund, J. -E.; Winningham, D. +16 more
We present the results of a study based on several events of broadband ULF/ELF emissions observed in the auroral region by the CLUSTER multi-spacecraft at distances around 4-5 RE. These emissions, observed below the ion plasma frequency, are similar to the broadband emissions observed at lower altitudes (800-4000 km) by rockets (e.g. AM…
Interstellar H2 in M 33 detected with FUSE
Wakker, B. P.; de Boer, K. S.; Marggraf, O. +2 more
FUSE spectra of the four brightest H Ii regions in
Observations of the upper solar chromosphere with SUMER
Wilhelm, K.; Kalkofen, W.
The structure and dynamics of the solar chromosphere are still matters of debate. The chromospheric network reflecting the supergranulation of the outer convection zone of the Sun is a prominent feature of the lower solar atmosphere that extends into the transition zone between chromosphere and corona. In particular, the physics of the so-called `…
A Deep Chandra X-Ray Observation of NGC 1637
Leonard, Douglas C.; Wang, Q. Daniel; Immler, Stefan +1 more
We present a deep (168 ks) Chandra observation of the nearby face-on spiral galaxy NGC 1637 and study the X-ray source population. A total of 32 X-ray sources are detected within the D25 ellipse of NGC 1637, each of which is found to be variable during the 629 day period covered by the observations. Deep Hubble Space Telescope WFPC2 obs…
NGC 5953/54: BVRIHαJK photometry and [N II] Fabry-Perot interferometry. I. The data
Rosado, M.; Dultzin-Hacyan, D.; Fuentes-Carrera, I. +3 more
We present new BVRIHαJK imaging and [N II] scanning Fabry-Perot observations for the interacting galaxy pair NGC 5953/54. Morphology is reviewed using a combination of contrast-enhanced images, color-index maps, and geometric (radial µ ɛ = 1 - b/a, PA and a4/a) profile parameters. Our data are complemented by archived V/R/H images…
Constraints from Infrared Space Observatory Data on the Velocity Law and Clumpiness of WR 136
Ignace, R.; Cassinelli, J. P.; Quigley, M. F.
Observations with the Infrared Space Observatory (ISO) SWS spectrometer are used to constrain the velocity law and wind clumping of the well-studied Wolf-Rayet (W-R) star WR 136 (HD 192163, WN6). Because the free-free continuum opacity in W-R winds increases steadily with wavelength in the IR, each point in the continuous spectrum may be regarded …
Deep ISOPHOT far-infrared imaging of M 86
Fabian, A. C.; Bregman, J. N.; Elmegreen, D. M. +2 more
Deep far-infrared (FIR) imaging data obtained with ISOPHOT at 60 µm, 90 µm, 150 µm, and 180 µm reveal a complex FIR morphology of the Virgo cluster elliptical M 86 (NGC 4406). A close pair of sources is associated with the centre of the M 86 galaxy and optically discovered dust streamers. Both components have a cold FIR spe…
An XMM-Newton Observation during the 2000 Outburst of SAX J1808.4-3658
Wijnands, Rudy
I present an XMM-Newton observation of the accretion-driven millisecond X-ray pulsar SAX J1808.4-3658 during its 2000 outburst. The source was conclusively detected, albeit at a level of only ~2×1032 ergs s-1. The source spectrum could be fitted with a power-law model (with a photon index of ~2.2), a neutron star atmosphere m…
The corona of HD 223460 (HR 9024)
Gondoin, P.
HD 223460 (HR 9024), a chromospherically active late-type giant with a high X-ray luminosity, was observed by the XMM-Newton space observatory. Series of lines of highly ionized Fe and several Lyman lines of hydrogen-like ions and triplet lines of helium-like ions are visible in the reflection grating spectra, most notably from O and Ne. Analysis …