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Metric observations of transient, quasi-periodic radio emission from the solar corona in association with a ``halo'' CME and an ``EIT wave'' event
Ramesh, R.; Kathiravan, C.; Ebenezer, E. +1 more
We present metric radio observations of quasi-periodic emission from the solar corona in close association with a ``halo'' CME and an ``EIT wave'' phenomenon. The radio event lasted for about 60 s. Its mean periodicity was ~8.8 s. The estimated Alfvén speed in the corona was 1034 km s-1. The derived height of the source region of the ob…
Observations of oscillations in the transition region above sunspots
Curdt, W.; Staude, J.; Rendtel, J.
Observations during two campaigns of the SUMER spectrograph and the EIT imager onboard SoHO were used to analyse oscillations in bright sunspot plumes. We report variations of both intensity and velocity seen in EUV emission lines originating in the sunspot upper chromosphere and the transition region. The wavelet analysis reveals rapidly changing…
SPI/INTEGRAL observation of the Cygnus region
Boggs, S.; von Kienlin, A.; Bouchet, L. +22 more
We present the analysis of the first observations of the Cygnus region by the SPI spectrometer onboard the Integral Gamma Ray Observatory, encompassing ~600 ks of data. Three sources namely Cyg X-1, Cyg X-3 and EXO 2030+375 were clearly detected. Our data illustrate the temporal variability of Cyg X-1 in the energy range from 20 keV to 300 keV. Th…
Near-infrared and ISOCAM observations of the Chamaeleon II dark cloud
Olofsson, G.; Gómez, M.; Persi, P. +1 more
An infrared study including ISOCAM images at 6.75 and 14.3 mu m of a large portion (28 arcmin x 26 arcmin) of the Chamaeleon II dark cloud and sub-arcsec resolution JHKs images of the central (4.9 arcmin x 4.9 arcmin) area is presented. Combining the ISOCAM observations with J and Ks photometry obtained with DENIS, we have fo…
IBIS preliminary results on Cygnus X-1 spectral and temporal characteristics
Goldoni, P.; Di Cocco, G.; Malaguti, G. +11 more
We report preliminary results of a broadband spectral and temporal study of the black-hole binary Cyg X-1 performed with the IBIS telescope. Cyg X-1 was the first pointed celestial target of IBIS during the INTEGRAL Performance and Verification Phase, 2002 Nov.-Dec., for a total observing time of ~ 2 Ms in both staring and dithering mode. Here, we…
Stellar content of NGC 404 - The nearest S0 Galaxy
Tikhonov, N. A.; Galazutdinova, O. A.; Aparicio, A.
We report V -band and I -band CCD stellar and surface photometry of the galaxy NGC 404 , taken with HST WFPC2 and the 2.5 m Nordic telescope. The colour-magnitude diagram for the stars in this galaxy is typical of that of spheroidal systems (i.e. it lacks luminous, young stars but contains a large number of Asymptotic Giant Branch (AGB) and Red Gi…
The dynamics of the nebula M1-67 around the run-away Wolf-Rayet star WR 124
Lamers, H. J. G. L. M.; van der Sluys, M. V.
A new point of view on the dynamics of the circumstellar nebula M1-67 around the run-away Wolf-Rayet (WR) star WR 124 is presented. We simulated the outbursts of nebulae with different morphologies, to compare the results to the observed dynamical spectra of M1-67. We found that it has been interacting with the surrounding ISM and has formed a bow…
On the location and composition of the dust in the MCG-6-30-15 warm absorber
Ballantyne, D. R.; Murray, N.; Weingartner, J. C.
The warm absorber observed in the Seyfert 1 galaxy MCG-6-30-15 is known to consist of at least two zones and very likely contains dust. Hubble Space Telescope images of MCG-6-30-15 show a dust lane crossing the galaxy just below the nucleus. In this paper, we argue that this dust lane is responsible for the observed reddening of the nuclear emissi…
XMM observation of the dynamically young galaxy cluster CL 0939+4713
Schindler, S.; Castillo-Morales, A.; De Filippis, E.
We present an XMM observation of the distant galaxy cluster CL 0939+4713. The X-ray image shows pronounced substructure, with two main subclusters which have even some internal structure. This is an indication that the cluster is a dynamically young system. This conclusion is supported by the temperature distribution: a hot region is found between…
GRB 021125: The first GRB imaged by INTEGRAL
Götz, D.; Goldoni, P.; Mereghetti, S. +12 more
In the late afternoon of November 25th, 2002 a gamma-ray burst (GRB) was detected in the partially coded field of view (about 7.3deg from the centre) of the imager IBIS on board the INTEGRAL satellite. The instruments on-board INTEGRAL allowed, for the first time, the observation of the prompt gamma-ray emission over a broad energy band…