Search Publications
High resolution γ-ray spectroscopy of flares on the east and west limbs of the Sun
Kiener, J.; Tatischeff, V.; Weidenspointner, G. +2 more
A new generation of Ge-based high-resolution gamma-ray spectrometers has allowed accurate measurements to be made of the profiles, widths and energies of the gamma-ray lines emitted in the impulsive phases of solar flares. Here we present measurements in two flares of the energies of the de-excitation lines of 12C and 16O at …
Multispectral analysis of solar EUV images: linking temperature to morphology
Auchère, F.; Dudok de Wit, T.
Context: Solar images taken simultaneously at different wavelengths in the EUV are widely used for understanding structures such as flares, coronal holes, loops, etc. The line-of-sight integration and the finite spectral resolution of EUV telescopes, however, hinders interpretation of these individual images in terms of temperature bands. Traditio…
Narrow-line AGN in the ISO-2MASS survey
Cesarsky, C.; Siebenmorgen, R.; Haas, M. +9 more
Context: A long-standing challenge of observational AGN research is to find type 2 quasars, the luminous analogues of Seyfert-2 galaxies.
Aims: We search for luminous narrow-line type 2 AGN, characterise their properties, and compare them with broad-line type 1 AGN.
Methods: Combining the ISOCAM parallel survey at 6.7 µm with 2MASS, …
A 100 ks XMM-Newton view of the Seyfert 1.8 ESO 113-G010. Discovery of large X-ray variability and study of the Fe Kα line complex
Bianchi, S.; Grosso, N.; Uttley, P. +6 more
Context: The Seyfert 1.8 galaxy ESO 113-G010 had been observed for the first time above 2 keV by XMM-Newton during a short exposure (~4 ks) in May 2001. In addition to a significant soft X-ray excess, it showed one of the strongest (in EW) redshifted Fe Kα lines, at 5.4 keV.
Aims: We present here a long (100 ks) XMM-Newton follow-up of this so…
XMM-Newton view of galaxy pairs: activation of quiescent black holes?
Guainazzi, M.; Santos-Lleó, M.; Jiménez-Bailón, E. +4 more
We report on XMM-Newton observations of three nearby galaxy pairs, AM0707-273, AM1211-465, and AM2040-674. All six galaxies were previously classified as HII galaxies based on optical and IR spectroscopic analysis. All galaxies were detected with XMM-Newton and each member was isolated and analyzed independently. The X-ray spectra reveal strong ev…
Abundances of planetary nebula M 1-42
Pottasch, S. R.; Bernard-Salas, J.; Roellig, T. L.
The spectra of the planetary nebula M 1-42 is reanalysed using spectral measurements made in the mid-infrared with the Spitzer Space Telescope. The aim is to determine the chemical composition of this object. We also make use of ISO, IUE and ground based spectra. Abundances determined from the mid- and far-infrared lines, which are insensitive to …
The ISOPHOT 170 µm Serendipity Survey. IV. The far-infrared sky atlas
Krause, O.; Lemke, D.; Klaas, U. +1 more
Aims:To further increase the scientific utilization of the strip scanning measurements of the ISOPHOT Serendipity Survey (ISOSS), the slew data has been assembled to a sky atlas with ≈15% sky coverage in the hitherto unobserved far-infrared wavelength band around 170 µm.
Methods: The redundant information of the brightnesses at slew cros…
The solar radius in the EUV during the cycle XXIII
Giménez de Castro, C. G.; Varela Saraiva, A. C.; Costa, J. E. R. +1 more
Aims:We aim to determine the solar transition region and coronal radius at EUV wavelengths and its time evolution during Solar Cycle XXIII.
Methods: We use daily 30.4 and 17.1 nm images obtained by the Extreme Ultraviolet Imager (EIT) aboard the SoHO satellite and derive the solar radius by fitting a circle to the limb brightness ring.
Res…
IGR J17497-2821 : a new X-ray nova
Paltani, S.; Gehrels, N.; Walter, R. +8 more
Context: A new hard X-ray transient has been discovered by INTEGRAL on 2006 Sep. 17 at 1 degree from the Galactic Centre.
Aims: INTEGRAL, Swift/XRT and optical photometric observations are used to characterize
Methods: The X-ray position has been refined to arcsec level through a…
A synchrotron self-Compton model with low-energy electron cut-off for the blazar S5 0716+714
Kirk, J. G.; Tsang, O.
Context: In a self-absorbed synchrotron source with power-law electrons, rapid inverse Compton cooling sets in when the brightness temperature of the source reaches T_B∼1012 K. However, brightness temperatures inferred from observations of intra-day variable sources (IDV) are well above the “Compton catastrophe” limit. This can be under…