Search Publications
Soft X-Ray Excess Emission in Clusters of Galaxies Observed with XMM-Newton
Bonamente, M.; Lumb, D.; Nevalainen, J. +1 more
We present results on the spectroscopic analysis of XMM-Newton EPIC data of the central 0.5 h-150 Mpc regions of the clusters of galaxies Coma, A1795, and A3112. The temperature of the hot intracluster gas as determined by modeling the 2-7 keV PN and MOS data is consistent with that inferred from the Fe XXV/Fe XXVI line ratio…
First results from the INTEGRAL galactic plane scans
Strong, A. W.; Mereghetti, S.; Gehrels, N. +12 more
Scans of the Galactic plane performed at regular intervals constitute a key element of the guaranteed time observations of the INTEGRAL observing programme. These scans are done for two reasons: frequent monitoring of the Galactic plane in order to detect transient sources, and time resolved mapping of the Galactic plane in continuum and diffuse l…
On the origin of the X-rays and the nature of accretion in NGC 4261
Brandt, W. N.; Gliozzi, M.; Sambruna, R. M.
We report on the X-ray properties of the radio galaxy
Space Telescope Imaging Spectrograph Survey of Far-Ultraviolet Coronal Forbidden Lines in Late-Type Stars
Ayres, Thomas R.; Redfield, Seth; Harper, Graham M. +4 more
We describe an extensive search with the Space Telescope Imaging Spectrograph (STIS) for ultraviolet coronal (T>106 K) forbidden lines in a sample of 29 F-M dwarfs, giants, and supergiants. Measuring coronal lines in the 1150-1700 Å band with STIS has important advantages of superior velocity resolution and an absolute wavelength cal…
Absolute timing with IBIS, SPI and JEM-X aboard INTEGRAL. Crab main-pulse arrival times in radio, X-rays and high-energy gamma -rays
Walter, R.; Foschini, L.; Kuiper, L. +1 more
We have verified the absolute timing capabilities of the high-energy instruments aboard INTEGRAL, i.e. the imager IBIS, the spectrometer SPI and the X-ray monitor JEM-X. Calibration observations of the Crab, contemporaneous with the Rossi X-ray Timing Explorer (RXTE), have been used to measure the absolute phase of the main pulse of the Crab pulse…
The Physical Parameters, Excitation, and Chemistry of the Rim, Jets, and Knots of the Planetary Nebula NGC 7009
Corradi, Romano L. M.; Gonçalves, Denise R.; Mampaso, Antonio +1 more
We present long-slit optical spectra along the major axis of the planetary nebula NGC 7009. These data allow us to discuss the physical, excitation, and chemical properties of all the morphological components of the nebula, including its remarkable systems of knots and jets. The main results of this analysis are the following: (1) the electron tem…
Core radius evolution of star clusters
Mackey, A. D.; Wilkinson, M. I.; Tout, C. A. +2 more
We use N-body simulations of star clusters to investigate the possible dynamical origins of the observed spread in core radius among intermediate-age and old star clusters in the Large Magellanic Cloud (LMC). Two effects are considered, a time-varying external tidal field and variations in primordial hard binary fraction. Simulations of clusters o…
Spatially-resolved spectrophotometric analysis and modelling of the Superantennae
Berta, S.; Fritz, J.; Franceschini, A. +2 more
We have performed spatially-resolved spectroscopy of the double-nucleated Ultra-Luminous Infrared Galaxy IRAS 19254-7245, ``the Superantennae'', along the line connecting the two nuclei. These data are analysed with a spectral synthesis code, to derive the star formation and extinction properties of the galaxy. The star formation history (SFH) of …
The dust disk of HR 4049. Another brick in the wall
Dominik, C.; van Winckel, H.; Dullemond, C. P. +1 more
We present the Spectral Energy Distribution of HR 4049 based on literature data and new continuum measurements at 850 µm . The SED shows variable absorption in the UV, and a large IR excess, both caused by circumstellar dust. The shape of the IR excess from 1 µm all the way down to 850 µm can be nearly perfectly fitted with a sin…
The X-ray spectrum of the North Polar Spur
Warwick, R. S.; Snowden, S. L.; Burrows, D. N. +2 more
An analysis is presented of the soft X-ray background spectrum measured by the EPIC-MOS cameras on XMM-Newton in three observations targeted on the North Polar Spur (NPS). Three distinct Galactic plasma components are identified: a cool local hot bubble (LHB) component, Tlo~ 0.1 keV; a cool Galactic halo component, at a similar temperat…