Search Publications
Soft X-ray emission lines in the afterglow spectrum of GRB 011211: A detailed XMM-Newton analysis
Watson, D.; O'Brien, P. T.; Reeves, J. N. +2 more
We report on an XMM-Newton observation of the X-ray afterglow of the Gamma Ray Burst GRB 011211, originally detected by Beppo-SAX on 11th December 2001. The early afterglow spectrum obtained by XMM-Newton, observed 11 hours after the initial burst, appeared to reveal decaying H-like Kalpha emission lines of Mg, Si, S, Ar and Ca, arising in enriche…
Do bulges of early- and late-type spirals have different morphology?
Peletier, R. F.; Fathi, K.
We study HST/NICMOS H-band images of bulges of two equal-sized samples of early- (TRC3 <= 3) and late-type spiral (mainly Sbc-Sc) galaxies matched in outer disk axis ratio. We find that bulges of late-type spirals are more elongated than their counterparts in early-type spirals. Using a KS-test we find that the two distributions are …
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
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…
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…
Amplitude and orientation of prominence magnetic fields from constant-alpha magnetohydrostatic models
Aulanier, G.; Démoulin, P.
We analyze outputs from three-dimensional models for three observed filaments, which belong to the quiescent, intermediate and plage class respectively. Each model was calculated from a constant-alpha magnetohydrostatic extrapolation, assuming that the prominence material is located in magnetic dips, so that the field is nearly horizontal througho…
Spectroscopic diagnostics of an Hα and EUV filament observed with THEMIS and SOHO
Heinzel, P.; Schmieder, B.; Tziotziou, K.
A long filament has been observed with THEMIS/MSDP and SOHO/CDS - SUMER, during a coordinated campaign (JOPs 131/95) on May 5, 2000. The data were (a) 2-D Hα spectra, observed using THEMIS, (b) Lyman series spectra and Lyman continuum, observed using SOHO/SUMER, and (c) EUV spectra (in O V 629 Å, Mg X 624 Å, Si Xii 520 Å, Ca X 557 Å and He I 584 Å…
The afterglow and the host galaxy of GRB 011211
Kouveliotou, C.; Tanvir, N.; Pedersen, H. +19 more
We present optical, near-infrared, and X-ray observations of the optical afterglow (OA) of the X-ray rich, long-duration gamma-ray burst GRB 011211. Hubble Space Telescope (HST) data obtained 14, 26, 32, and 59 days after the burst, show the host galaxy to have a morphology that is fairly typical of blue galaxies at high redshift. We measure its m…