Search Publications
Warm dust and aromatic bands as quantitative probes of star-formation activity
Förster Schreiber, N. M.; Roussel, H.; Sauvage, M. +1 more
We combine samples of spiral galaxies and starburst systems observed with ISOCAM on board ISO to investigate the reliability of mid-infrared dust emission as a quantitative tracer of star formation activity. The total sample covers very diverse galactic environments and probes a much wider dynamic range in star formation rate density than previous…
The basic characteristics of EUV post-eruptive arcades and their role as tracers of coronal mass ejection source regions
Bothmer, V.; Tripathi, D.; Cremades, H.
The Extreme ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO) spacecraft provides unique observations of dynamic processes in the low corona. The EIT 195 Å data taken from 1997 to the end of 2002 were investigated to study the basic physical properties of post-eruptive arcades (PEAs) and their relationship …
Observations of the helium focusing cone with pickup ions
Geiss, J.; Möbius, E.; Noda, H. +12 more
The helium gravitational focusing cone has been observed using pickup He+, first during the solar minimum in 1984-1985 with the AMPTE/IRM spacecraft, and again in more detail from 1998 to 2002 with ACE and in 2000 with Nozomi. Five traversals of the cone allow us to obtain an accurate determination of the ecliptic longitude of the inter…
Exploring the X-ray sky with the XMM-Newton bright serendipitous survey
Page, M. J.; Barcons, X.; Carrera, F. J. +11 more
We present here ``The XMM-Newton Bright Serendipitous Survey'', composed of two flux-limited samples: the XMM-Newton Bright Source Sample (BSS, hereafter) and the XMM-Newton ``Hard'' Bright Source Sample (HBSS, hereafter) having a flux limit of f_x≃ 7 × 10-14 erg cm-2 s-1 in the 0.5-4.5 keV and 4.5-7.5 keV energy b…
Contribution of the disk emission to the broad emission lines in AGNs: Two-component model
Bon, E.; Popović, L. Č.; Ilić, D. +1 more
We present an investigation of the structure of the emission line region in a sample of 12 single-peaked Active Galactic Nuclei (AGNs). Using the high resolution Hβ and Hα line profiles observed with the Isaac Newton Telescope (La Palma) we study the substructure in the lines (such as shoulders or bumps) which can indicate a disk or disk-like emis…
On the sizes of stellar X-ray coronae
Schmitt, J. H. M. M.; Audard, M.; Güdel, M. +2 more
Spatial information from stellar X-ray coronae cannot be assessed directly, but scaling laws from the solar corona make it possible to estimate sizes of stellar coronae from the physical parameters temperature and density. While coronal plasma temperatures have long been available, we concentrate on the newly available density measurements from li…
Bright OB stars in the Galaxy. I. Mass-loss and wind-momentum rates of O-type stars: A pure H\alpha analysis accounting for line-blanketing
Puls, J.; Markov, H.; Markova, N. +1 more
We study mass-loss and wind momentum rates of 29 Galactic O-type stars with luminosity classes I, III and V by means of a pure H\alpha profile analysis and investigate to what extent the results compare to those originating from a state-of-the-art, complete spectral analysis. Our investigation relies on the approximate method developed by \citet{P…
Elemental abundances in the intracluster medium as observed with XMM-Newton
Kaastra, J. S.; Tamura, T.; Bleeker, J. A. M. +2 more
XMM-Newton observations of 19 galaxy clusters are used to measure the elemental abundances and their spatial distributions in the intracluster medium. The sample mainly consists of X-ray bright and relaxed clusters with a cD galaxy. Along with detailed Si, S and Fe radial abundance distributions within 300-700 kpc in radius, the O abundances are a…
Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton
Audard, M.; Güdel, M.; Linsky, J. L. +2 more
We report results from a comprehensive study of the nearby M dwarf Proxima Centauri with the XMM-Newton satellite, using simultaneously its X-ray detectors and the Optical Monitor with its U band filter. We find strongly variable coronal X-ray emission, with flares ranging over a factor of 100 in peak flux. The low-level emission is found to be co…
Study of the properties and spectral energy distributions of the Herbig AeBe stars HD 34282 and HD 141569
Rauer, H.; Schneider, J.; Eiroa, C. +21 more
We present a study of the stellar parameters, distances and spectral energy distributions (SEDs) of