Search Publications
Discovery of narrow X-ray absorption features from the dipping low-mass X-ray binary X 1624-490 with XMM-Newton
Parmar, A. N.; Boirin, L.; Oosterbroek, T. +1 more
We report the discovery of narrow X-ray absorption features from the dipping low-mass X-ray binary X1624-490 during an XMM-Newton observation in 2001 February. The features are identified with the Kalpha absorption lines of Fe XXV and Fe XXVI and have energies of 6.72 +/- 0.03 keV and 7.00 +/- 0.02 keV and equivalent widths (EWs) of -7.5 +1.7…
HST observations of the protoplanetary nebula OH 231.8+4.2: The structure of the jets and shocks
Sahai, R.; Sánchez Contreras, C.; Alcolea, J. +1 more
We present high-resolution images obtained with the WFPC2, on board the HST, of the protoplanetary nebula (PPN) OH 231.8+4.2. Hα and NII line emission and scattered light in the continuum at 6750 and 7910 Å were observed. We also discuss NIR NICMOS images from the HST archive. The images show with high accuracy the shape and excitation state of th…
ISO ammonia line absorption reveals a layer of hot gas veiling Sgr B2
Prusti, T.; Ceccarelli, C.; Caux, E. +7 more
We report the first results of the unbiased spectral high resolution survey obtained towards Sgr B2 with the Long Wavelength Spectrometer on board ISO. The survey detected more than one hundreds lines from several molecules. Ammonia is the molecule with the largest number (21) of detected lines in the survey. We detected NH3 transitions…
On electron acceleration at CIR related shock waves
Mann, G.; Keppler, E.; Roelof, E. C. +1 more
The interaction of fast and slow speed solar wind streams leads to the formation of so-called corotating interaction regions (CIRs) in the heliosphere. These CIRs are often associated with shock waves, at which electrons are accelerated as observed by the Ulysses spacecraft. A correlation between the ratio of energetic electron fluxes at the cross…
Probing the mass loss history of carbon stars using CO line and dust continuum emission
Ryde, N.; Olofsson, H.; Schöier, F. L.
An extensive modelling of CO line emission from the circumstellar envelopes around a number of carbon stars is performed. By combining radio observations and infrared observations obtained by ISO the circumstellar envelope characteristics are probed over a large radial range. In the radiative transfer analysis the observational data are consistent…
On the absence of wind bow-shocks around OB-runaway stars: Probing the physical conditions of the interstellar medium
Kaper, L.; Huthoff, F.
High-resolution IRAS maps are used to search for the presence of stellar-wind bow-shocks around high-mass X-ray binaries (HMXBs). Their high space velocities, recently confirmed with Hipparcos observations, combined with their strong stellar winds should result in the formation of wind bow-shocks. Except for the already known bow-shock around Vela…
A 25 micron search for Vega-like disks around main-sequence stars with ISO
Kessler, M. F.; Siebenmorgen, R.; Dominik, C. +5 more
We present an ISO 25 mu m photometric survey of a sample of 81 nearby main-sequence stars in order to determine the incidence of ``warm'' dust disks. All stars were detected by ISO. We used an empirical relation to estimate the photospheric flux of the stars at 25 mu m. We find 5 stars (6%) with excess above the photospheric flux which we attribut…
The role of magnetic bald patches in surges and arch filament systems
Mandrini, C. H.; Schmieder, B.; Démoulin, P. +2 more
The short-lived active region (AR) NOAA 7968 was thoroughly observed all along its disk transit (June 3 to 10, 1996) from space and from the ground. During the early stage of its evolution, flux emerged in between the two main polarities and arch filament systems (AFS) were observed to be linked to this emergence. New bipoles and a related surge w…
X-ray sources in the starburst spiral galaxy M 83. Nuclear region and discrete source population
Soria, R.; Wu, K.
Chandra has resolved the starburst nuclear region of the face-on grand-design spiral M 83. Eighty-one point sources are detected (above 3.5-sigma ) in the ACIS S3 image, and 15 of them are within the inner 16\arcsec region of the galaxy. A point source with Lx ~ 3 x 1038 erg s-1 in the 0.3-8.0 keV band is found to …
Simultaneous X-ray spectroscopy of YY Gem with Chandra and XMM-Newton
Schmitt, J. H. M. M.; Burwitz, V.; Neuhäuser, R. +7 more
We report on a detailed study of the X-ray spectrum of the nearby eclipsing spectroscopic binary YY Gem. Observations were obtained simultaneously with both large X-ray observatories, XMM-Newton and Chandra. We compare the high-resolution spectra acquired with the Reflection Grating Spectrometer onboard XMM-Newton and with the Low Energy Transmiss…