Search Publications
An ISOCAM survey through gravitationally lensing galaxy clusters. I. Source lists and source counts for A370, A2218 and A2390
Kneib, J. -P.; Altieri, B.; Elbaz, D. +11 more
ESA's Infrared Space Observatory (ISO) was used to perform a deep survey with ISOCAM through three massive gravitationally lensing clusters of galaxies. The total area surveyed depends on source flux, with nearly seventy square arcminutes covered for the brighter flux levels in maps centred on the three clusters Abell 370, Abell 2218 and Abell 239…
Caught in the act: A helium-reionizing quasar near the line of sight to Q0302-003
Reimers, D.; Jakobsen, P.; Jansen, R. A. +1 more
We report the discovery of a quasar at z=3.050+/-0.003, closely coincident in redshift with the isolated low-opacity feature seen near z =~ 3.056 in the otherwise black portion of the He Ii Gunn-Peterson absorption trough seen toward the z=3.286 background quasar Q0302-003, located 6farcm5 away on the sky. We explore plausible models for the He Ii…
XMM-Newton confirmation of soft X-ray excess emission in clusters of galaxies - The discovery of O VII emission from an extended warm baryonic component
Kaastra, J. S.; Tamura, T.; den Herder, J. W. +2 more
We investigate a sample of 14 clusters of galaxies observed with XMM-Newton in a search for soft X-ray excess emission. In five of these clusters a significant soft excess is evident. This soft X-ray excess is compared with the thermal emission from both the hot intracluster gas and any cooling (flow) gas that may be present. A warm (kT=0.2 keV), …
INTEGRAL discovery of a bright highly obscured galactic X-ray binary source IGR J16318-4848
de Plaa, J.; Parmar, A. N.; Tomsick, J. A. +8 more
INTEGRAL regularly scans the Galactic plane to search for new objects and in particular for absorbed sources with the bulk of their emission above 10-20 keV. The first new INTEGRAL source was discovered on 2003 January 29, 0.5degr from the Galactic plane and was further observed in the X-rays with XMM-Newton. This source, IGR J16318-4848, is intri…
Modelling the rotational modulation of the Sun as a star
Barge, P.; Llebaria, A.; Pagano, I. +2 more
We analyse the time variability of the total solar irradiance (TSI) as measured by VIRGO/SoHO in order to model the variability of the Sun as a star. Apart from the phases near the minimum at the beginning of activity cycle 23, the period of the rotational modulation is significantly different from the solar synodic period as a consequence of the …
Origin of the 6.85 µm band near young stellar objects: The ammonium ion (NH4+) revisited
Schutte, W. A.; Khanna, R. K.
We have investigated whether the nu4 feature of NH4+ is a viable candidate for the 6.85 mu m absorption band seen towards embedded young stellar objects. To produce NH4+ astrophysical ice analogs consisting of H2O, CO2, NH3 and O2 were UV photolysed.…
A broad absorption feature in the X-ray spectrum of the isolated neutron star RBS1223 (1RXS J130848.6+212708)
Haberl, F.; Motch, C.; Hasinger, G. +2 more
X-ray spectra of the isolated neutron star RBS1223 obtained with the instruments on board XMM-Newton in December 2001 and January 2003 show deviations from a Planckian energy distribution at energies below 500 eV. The spectra are well fit when a broad, Gaussian-shaped absorption line with sigma = 100 eV and centered at an energy of 300 eV is added…
XMM-Newton observations reveal AGN in apparently normal galaxies
Pietsch, W.; Wolter, A.; Barcons, X. +12 more
We have performed a detailed analysis of 3 optically normal galaxies extracted from the XMM Bright Serendipitous Source Sample. Thanks to the good statistics of the XMM-Newton data, we have unveiled the presence of an AGN in all of them. In particular, we detect both X-ray obscured (NH>1022 cm-2) and unobscured …
Optical and near-infrared observations of the GRB020405 afterglow
Pian, E.; Palazzi, E.; Frontera, F. +33 more
We report on photometric, spectroscopic and polarimetric monitoring of the optical and near-infrared (NIR) afterglow of GRB020405. Ground-based optical observations, performed with 8 different telescopes, started about 1 day after the high-energy prompt event and spanned a period of ~ 10 days; the addition of archival HST data extended the coverag…
New insights to the photometric structure of Blue Compact Dwarf galaxies from deep Near-Infrared studies. I. Observations, surface photometry and decomposition of surface brightness profiles
Papaderos, P.; Noeske, K. G.; Fricke, K. J. +1 more
We have analyzed deep Near Infrared (NIR) broad band images for a sample of Blue Compact Dwarf Galaxies (BCDs), observed with the ESO NTT and Calar Alto 3.6 m telescopes. The data presented here allows for the detection and quantitative study of the extended stellar low-surface brightness (LSB) host galaxy in all sample BCDs. NIR surface brightnes…