Search Publications

The XMM-Newton view of stellar coronae: High-resolution X-ray spectroscopy of Capella
DOI: 10.1051/0004-6361:20000246 Bibcode: 2001A&A...365L.329A

Bromage, G. E.; Raassen, A. J. J.; Mewe, R. +5 more

We present the high-resolution RGS X-ray spectrum of the stellar binary Capella observed by the XMM-Newton satellite. A multi-thermal approach has first been applied to fit the data and derive elemental abundances. Using the latter, the emission measure distribution has been reconstructed using a Chebychev polynomial fit. Its shape is found to dis…

2001 Astronomy and Astrophysics
XMM-Newton 98
Time-resolved spectral analysis of the pulsating helium star V652 Her
DOI: 10.1051/0004-6361:20010954 Bibcode: 2001A&A...376..497J

Jeffery, C. S.; Woolf, V. M.; Pollacco, D. L.

A series of 59 moderate-resolution high signal-to-noise spectra of the pulsating helium star V652 Her covering 1.06 pulsation cycles was obtained with the William Herschel Telescope. These have been supplemented by archival ultraviolet and visual spectrophotometry and used to make a time-dependent study of the properties of

2001 Astronomy and Astrophysics
IUE 97
Search for NH3 ice in cold dust envelopes around YSOs
DOI: 10.1051/0004-6361:20000174 Bibcode: 2001A&A...365..144D

Dartois, E.; d'Hendecourt, L.

We present a study of the 3.1 micron absorption band, attributed to the OH stretching mode of the water molecule in the form of solid ice, observed in many protostellar lines of sight by the SWS instrument on board ISO. Using ice optical constants and Mie theory, we obtain reasonable fits to the peculiar band shapes observed in twelve sources. The…

2001 Astronomy and Astrophysics
ISO 94
Helium-like triplet density diagnostics. Applications to CHANDRA-LETGS X-ray observations of Capella and Procyon
DOI: 10.1051/0004-6361:20000419 Bibcode: 2001A&A...367..282N

Schmitt, J. H. M. M.; Kaastra, J. S.; Burwitz, V. +6 more

Electron density diagnostics based on the triplets of helium-like C v, N vi, and O vii are applied to the X-ray spectra of Capella and Procyon measured with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra X-ray Observatory. New theoretical models for the calculation of the line ratios between the forbidden (f), interc…

2001 Astronomy and Astrophysics
IUE 92
Non-axisymmetric accretion on the classical TTS RW Aur A
DOI: 10.1051/0004-6361:20010203 Bibcode: 2001A&A...369..993P

Tuominen, I.; Gahm, G. F.; Gameiro, J. F. +5 more

High-resolution spectroscopic monitoring of the exceptionally active classical T Tauri star (CTTS) RW Aur A was carried out in three seasons of 1996, 1998 and 1999 with simultaneous B, V photometry. The high quality spectra revealed a multicomponent structure of the spectrum, which includes: 1) a veiled photospheric spectrum of a K1-K4 star, 2) br…

2001 Astronomy and Astrophysics
IUE 91
XMM-Newton observation of an unusual iron line in the quasar Markarian 205
DOI: 10.1051/0004-6361:20000424 Bibcode: 2001A&A...365L.134R

Boller, Th.; O'Brien, P. T.; Reeves, J. N. +5 more

XMM-Newton observations of the low luminosity, radio-quiet quasar Markarian 205 have revealed a unique iron K emission line profile. In marked contrast to the broad and redshifted iron K line commonly seen in ASCA observations of Seyfert 1 galaxies, we find that a substantial amount of the line flux in Mrk 205 occurs above the neutral line energy …

2001 Astronomy and Astrophysics
XMM-Newton 89
XMM-Newton observations of NGC 253: Resolving the emission components in the disk and nuclear area
DOI: 10.1051/0004-6361:20000068 Bibcode: 2001A&A...365L.174P

Pietsch, W.; Read, A. M.; Ptak, A. +12 more

We describe the first XMM-Newton observations of the starburst galaxy NGC 253. As known from previous X-ray observations, NGC 253 shows a mixture of extended (disk and halo) and point-source emission. The high XMM-Newton throughput allows a detailed investigation of the spatial, spectral and variability proper…

2001 Astronomy and Astrophysics
XMM-Newton 87
The XMM-Newton view of stellar coronae: Flare heating in the coronae of HR 1099
DOI: 10.1051/0004-6361:20000085 Bibcode: 2001A&A...365L.318A

Mewe, R.; Audard, M.; Güdel, M.

The RS CVn system HR 1099 was observed by XMM-Newton for a time span of 25 days during the commissioning phase. Rotational modulation in the RGS light curve has been detected with maximum flux when the active K1 IV star is in front. Following a quiescent phase of emission, the rise and peak of a large flare were observed. Time-dependent spectrosco…

2001 Astronomy and Astrophysics
XMM-Newton 84
XMM-Newton observations of the cluster of galaxies Abell 496. Measurements of the elemental abundances in the intracluster medium
DOI: 10.1051/0004-6361:20011317 Bibcode: 2001A&A...379..107T

Kaastra, J. S.; Molendi, S.; Ferrigno, C. +2 more

The results from XMM-Newton observations of the relaxed cluster of galaxies Abell 496 are presented. The spatially-resolved X-ray spectra taken by the European Photon Imaging Cameras show a temperature drop and a Fe abundance increase in the intra-cluster medium (ICM) towards the cD galaxy at the cluster center. The abundances of Si and S also sho…

2001 Astronomy and Astrophysics
XMM-Newton 83
The X-ray spectrum of the supernova remnant 1E 0102.2-7219
DOI: 10.1051/0004-6361:20000231 Bibcode: 2001A&A...365L.231R

Behar, E.; Kahn, S. M.; den Herder, J. W. +2 more

In this letter we present the soft X-ray (5-35 Å) spectrum of the supernova remnant (SNR) 1E 0102.2-7219 in the Small Magellanic Cloud, acquired by the reflection grating spectrometers (RGS) aboard ESA's XMM-Newton Observatory. Because the RGS features a large dispersion angle, spatial-spectral confusion is suppressed even for m…

2001 Astronomy and Astrophysics
XMM-Newton 82