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An XMM-Newton view of the young open cluster NGC 6231. I. The catalogue
Gosset, E.; Rauw, G.; Vreux, J. -M. +2 more
This paper is the first of a series dedicated to the X-ray properties of the young open cluster NGC 6231. Our data set relies on an XMM-Newton campaign of a nominal duration of 180 ks and reveals that NGC 6231 is very rich in the X-ray domain too. Indeed, 610 X-ray sources are detected in the present field of view, centered on the cluster core. Th…
Structural parameters from ground-based observations of newly discovered globular clusters in NGC 5128
Geisler, D.; Gómez, M.; Richtler, T. +3 more
We have investigated a number of globular cluster candidates from a recent wide-field study by Harris et al. (2004a, AJ, 128, 712) of the giant elliptical galaxy
ISO mid-infrared spectroscopy of Galactic Bulge AGB stars
Blommaert, J. A. D. L.; Ganesh, S.; Glass, I. S. +8 more
Aims.To study the nature of Bulge AGB stars and in particular their circumstellar dust, we have analysed mid-infrared spectra obtained with the ISOCAM CVF spectrometer in three Bulge fields.
Methods: .The ISOCAM 5-16.5 µm CVF spectra were obtained as part of the ISOGAL infrared survey of the inner Galaxy. A classification of the shape o…
Near infra-red spectroscopy of the asteroid 21 Lutetia. I. New results of long-term campaign
Barucci, M. A.; Fulchignoni, M.; Vernazza, P. +4 more
Aims.Investigation of the physical nature of the asteroid 21 Lutetia, target of Rosetta mission, is required for the completion of its ground-based science and in the frame of its future fly-by. Monitoring this object is essential in preparing the future encounter with the spacecraft.
Methods: .The asteroid was observed with SpeX/IRTF in the s…
A torque reversal of 4U 1907+09
Santangelo, A.; Rodriguez, J.; Wilms, J. +5 more
Aims.We present an analysis of the accreting X-ray pulsar system 4U 1907+09 based on INTEGRAL data. The main focus of this analysis is a study of the timing behavior of this source. In addition we also show an analysis of the 5-90 keV spectrum.
Methods: .The data were extracted using the official INTEGRAL software OSA 5.1. Timing analysis was …
XMM-Newton observations of AM CVn binaries: V396 Hya and SDSS J1240-01
Groot, P. J.; Ramsay, G.; Hakala, P. +3 more
We present the results of XMM-Newton observations of two AM CVn systems - V396 Hya and SDSS J1240-01. Both systems are detected in X-rays and in the UV: neither shows coherent variability in their light curves. We compare the rms variability of the X-ray and UV power spectra of these sources with other AM CVn systems. Apart from ES Cet, AM CVn sou…
Analysis of IUE spectra of helium-rich white dwarf stars
Kepler, S. O.; Handler, G.; Koester, D. +1 more
We studied the class of DB white dwarf stars, using re-calibrated UV spectra for thirty four DBs obtained with the IUE satellite. By comparing the observed energy distributions with model atmospheres, we simultaneously determine spectroscopic distances (d), effective temperature (Teff), and surface gravities (log g). Using parallax meas…
Prospects for dark energy evolution: a frequentist multi-probe approach
Yvon, D.; Tao, C.; Tilquin, A. +4 more
A major quest in cosmology is to understand the nature of dark energy. It is now well known that the use of several cosmological probes is required to break the underlying degeneracies on cosmological parameters. In this paper, we present a method based on a frequentist approach that combines probes without any prior constraints. As one applicatio…
The XMM-Newton view of GRS 1915+105
Belloni, T.; Ponti, G.; Matt, G. +3 more
Two XMM-Newton observations of the black-hole binary GRS 1915+105 were triggered in 2004 (April 17 and 21), during a long "plateau" state of the source. We analyzed the data collected with EPIC-pn in timing and burst modes, respectively. Reflection Grating Spectrometers were used only on April 21st. The source 2-10 keV flux is 0.6 (unabsorbed: 0.9…
The XMM-Newton view of the Crab
Freyberg, M. J.; Wilms, J.; Kendziorra, E. +7 more
Aims.We discuss the current X-ray view of the Crab Nebula and Pulsar, summarising our analysis of observations of the source with the EPIC-pn camera on board the XMM-Newton observatory. Different modes of EPIC-pn were combined in order to yield a complete scenario of the spectral properties of the Crab resolved in space and time (pulse phase). In …