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XMM-Newton observations of β Centauri (B1 III): The temperature structure in the hot plasma and the photosphere-wind connection
Raassen, A. J. J.; Mewe, R.; Cassinelli, J. P. +2 more
We present XMM-Newton observations of the B giant β Centauri (B1 III). The spectra are rich of spectral lines from a wide range of ionization stages which indicate temperatures in the range ~0.1-0.6 keV. Simultaneous fits to the rgs, epic-mos, and epic-pn spectra yield three plasma temperatures (0.1, 0.2, and 0.6 keV), emission measures, and eleme…
Classical novae in outburst: evolution of the ultraviolet emission lines in CO novae
Altamore, A.; González-Riestra, R.; Cassatella, A.
A comparative study is made of the temporal changes of the ionization level in seven CO novae well monitored with the IUE satellite at low resolution. The investigation is based on the evolution of the fluxes in eight strong ultraviolet emission lines covering a wide range of ionization potentials, from Mg II (7.6 eV) to N V (77.5 eV). We find tha…
Discovery of a redshifted X-ray emission line in the symbiotic neutron star binary 4U 1700+24
Sokoloski, J. L.; Tiengo, A.; Miller, J. M. +4 more
We present the spectral analysis of an XMM-Newton observation of the X-ray binary 4U 1700+24, performed during an outburst in August 2002. The EPIC-PN spectrum above 1 keV can be modeled by a blackbody plus Comptonization model, as in previous observations. At lower energies, however, we detect a prominent soft excess, which we model with a broad …
A uniqueness result for a simple force-free magnetic field submitted to a topological constraint
Aly, J. J.
A proof is given of the following statement: if B is a smooth force-free magnetic field contained in a cylindrical domain of axis parallel to z and of star-shaped cross-section, and if B is topologically equivalent to the uniform field B0=B0z, then B=B0. In addition to being a very first step in the general study o…
Electron densities in EUV coronal bright points
Doyle, J. G.; Del Zanna, G.; Ugarte-Urra, I.
Electron density measurements of six coronal bright points have been obtained using line ratio diagnostics of four ions in the temperature range 1.3-2.0 × 106 K. The results suggest that BP plasma has more similarities to active region plasma than to quiet Sun plasma. Nevertheless, they do not show the exact same behaviour: the increase…
XMM-Newton and VLT observations of the afterglow of GRB 040827
Covino, S.; D'Avanzo, P.; Caraveo, P. A. +13 more
The field of the Gamma-Ray Burst GRB 040827 was observed with XMM-Newton and with the ESO/VLT starting 6 and 12 h after the burst, respectively. A fading X-ray afterglow is clearly detected with the XMM-Newton/EPIC instrument, with a time decay t-δ, with δ=1.41±0.10. Its spectrum is well described by a power law (photon index Γ=2.3±0.1)…
Abundances in planetary nebulae: Mz 3
Pottasch, S. R.; Surendiranath, R.
ISO spectra of the bipolar planetary nebula
The near-UV pulse profile and spectrum of the pulsar PSR B0656+14
Sollerman, J.; Lundqvist, P.; Shibanov, Yu. A. +2 more
We have observed the middle-aged pulsar PSR B0656+14 with the prism and the NUV MAMA detector of the Space Telescope Imaging Spectrograph (STIS) to measure the pulsar spectrum and periodic pulsations in the near-ultraviolet (NUV). The pulsations are clearly detected, double-peaked and very similar to the optical pulse profile. The NUV pulsed fract…
Spectroscopy and stellar populations of star-forming galaxies at z ~ 3 in the Hubble Deep Field - South
Burgarella, D.; Inoue, A. K.; Iwata, I.
We present results of VLT/FORS2 spectroscopy of galaxies at z ∼ 3 in the Hubble Deep Field - South (HDF-S). A sample of galaxies was drawn from the photometric redshift catalogue based on the HST/WFPC2 optical images and the deep near-infrared images obtained with VLT/ISAAC as a part of the Faint Infrared Extragalactic Survey (FIRES) project. We s…
The X-ray emission from Young Stellar Objects in the ρ Ophiuchi cloud core as seen by XMM-Newton
Grosso, N.; Montmerle, T.; Ozawa, H.