Search Publications
UVIS/HDAC Lyman-α observations of the geocorona during Cassini’s Earth swingby compared to model predictions
Keller, H. U.; Werner, S.; Korth, A. +1 more
The Hydrogen Deuterium Absorption Cell (HDAC) is part of the Ultraviolet Imaging Spectrograph (UVIS) experiment aboard the Cassini spacecraft. During Cassini's Earth swingby on August 18, 1999, HDAC was used as a photometer to measure solar Lyman-α radiation scattered by the neutral hydrogen atoms of the geocorona. These data provide information a…
Monte Carlo simulations of CASSINI/LEMMS
Livi, S.; Haggerty, D. K.
In an effort to characterize the response of the low energy magnetospheric measurements system (LEMMS) on the CASSINI spacecraft to energetic ions and electrons we have taken advantage of the excellent pre-launch beam calibrations in comparison to an extensive series of electron and ion Monte Carlo simulations. We selected the geometry and trackin…
Diagnostics of the Local Interstellar Medium using particles and UV radiation
Lallement, R.; Vallerga, J.; Raymond, J. R.
The chain of processes which govern trajectories and ionization of neutral particles from the circumsolar interstellar gas to the inner heliosphere can now be studied by combining several types of diagnostics: solar backscattered radiation (H and He), direct detection of neutral particles (He), detection of pickup ions of interstellar origin (H, H…
Physical structure of the local interstellar medium
Linsky, J. L.; Redfield, S.; Wood, B. E.
The physical structure and morphology of the interstellar medium that surrounds our solar system directly effects the heliosphere and the interplanetary environment. High resolution ultraviolet absorption spectra of nearby stars and the intervening interstellar medium, observed by the Hubble Space Telescope, provide important information about the…
X-ray emission of young SN Ia remnants as a probe for an explosion model
Lundqvist, P.; Sorokina, E. I.; Blinnikov, S. I. +1 more
We present results of hydrodynamical simulations of young supernova remnants. To model the ejecta, we use several models (discussed in the literature) of type Ia supernova explosions with different abundances. Our hydro models are one-dimensional and spherically symmetrical, but they take into account ionization kinetics with all important process…
X-ray broad line emission in Seyfert galaxies: Mrk 766 and NGC 4051
Page, M. J.; Branduardi-Raymont, G.; Mason, K. O. +3 more
Long (>100 ks) observations of the bright Seyfert galaxies Mrk 766 and NGC 4051 have been obtained using XMM- Newton. The RGS 5-38 Å spectra reveal evidence of broad features. These can be modelled with relativistic emission lines coming from the immediate vicinity of a massive rotating black hole. Lines of OVIII, NVII and CVI are required to r…
Properties of the isolated neutron star RX J185635-3754
Burwitz, V.; Neuhäuser, R.; Pons, J. A. +5 more
Despite improved observational capabilities, the surface properties of neutron stars remain uncertain. In principle, multiwavelength spectra can reveal their compositions and angular diameters and constrain the interior equation of state. The Chandra LETG spectrum of the brightest isolated neutron star is a featureless continuum. The X-ray blackbo…
Shock-cloud interactions in the Vela SNR: preliminary results of an XMM-Newton observation
Miceli, M.; Bocchino, F.; Maggio, A.
The study of the clumpy and irregular features in the X-ray emission of middle-aged supernova remnants shells allows us to shed light on the various characteristic of the interstellar medium, like its structure and composition. We have observed with XMM-Newton a small knot in the Vela SNR, which previous ROSAT studies have indicated as one of the …
Numerical simulation of the visible and near infrared radiance of Mars: effects of atmospheric scattering
Erard, S.; Blecka, M. I.
This paper presents new simulations of the radiance of the surface and atmosphere of Mars. Our modeling is directly connected with future spectrometric measurements of two instruments on Mars Express (short-wavelength channel of PFS and OMEGA) and of the VIRTIS spectrometer on-board Rosetta which was planned for observation of Mars in August 2005.…
High resolution spectroscopy of Seyfert warm absorbers with XMM-Newton
Kaastra, J. S.; Behar, E.; Sako, M. +5 more
We present results from the analysis of an XMM-Newton observation of the Seyfert 1 galaxy NGC 7469, the first high resolution X-ray spectrum of this source. The Reflection Grating Spectrometer (RGS) spectrum has several narrow absorption and emission lines of O, N, C and Ne, originating from gas at a range of ionisation parameters, from log ξ∼1.6 …