Search Publications
AFS dynamic evolution during the emergence of an active region
Romano, P.; Spadaro, D.; Contarino, L. +2 more
Using data acquired during an observational campaign carried out at the THEMIS telescope in IPM mode, coordinated with other ground- and space-based instruments (IOACT, TRACE, EIT/SOHO, MDI/SOHO), we have analyzed the first evolutionary phases of a recurrent active region (NOAA 10050), in order to study the morphology and dynamics of its magnetic …
X-ray flares from the ultra-luminous X-ray source in NGC 5408
Read, A. M.; Motch, C.; Soria, R. +1 more
We have studied an ultra-luminous X-ray source (ULX) in the dwarf galaxy NGC 5408 with a series of XMM-Newton observations, between 2001 July and 2003 January. We find that its X-ray spectrum is best fitted with a power law of photon index Γ ≈ 2.6-2.9 and a thermal component with blackbody temperature kTbb ≈ 0.12-0.14 keV. These spectra…
HD 108: The mystery deepens with XMM-Newton observations
Nazé, Y.; Rauw, G.; Vreux, J. -M. +1 more
In 2001, using a large spectroscopic dataset from an extensive monitoring campaign, we discovered that the peculiar Of star HD 108 displayed extreme line variations. This strange behaviour could be attributed to a variety of models, and an investigation of the high energy properties of HD 108 was needed to test the predictions from these models. O…
Discovery of the optical counterpart to the X-ray pulsar SAX J2103.5+4545
Reig, P.; Negueruela, I.; Fabregat, J. +3 more
We report optical and infrared photometric and spectroscopic observations that identify the counterpart to the 358.6-s X-ray transient pulsar
Long-term evolution of FU Orionis objects at infrared wavelengths
Prusti, T.; Csizmadia, Sz.; Ábrahám, P. +3 more
We investigate the brightness evolution of seven FU Orionis systems in the 1-100 µm wavelength range using data from the Infrared Space Observatory (ISO). The ISO measurements were supplemented by 2MASS and MSX observations performed in the same years as the ISO mission (1995-98). The spectral energy distributions (SEDs) based on these data …
Optical nuclei of radio-loud AGN and the Fanaroff-Riley divide
Kharb, P.; Shastri, P.
We investigate the nature of the point-like optical nuclei that have been found in the centres of the host galaxies of a majority of radio galaxies by the Hubble Space Telescope. We examine the evidence that these optical nuclei are relativistically beamed, and look for differences in the behaviour of the nuclei found in radio galaxies of the two …
An all-sky optical catalogue of radio/X-ray sources
Hardcastle, M. J.; Flesch, E.
We present an all-sky catalogue that aligns and overlays the ROSAT HRI, RASS, PSPC and WGA X-ray catalogues and the NVSS, FIRST and SUMSS radio catalogues onto the optical APM and USNO-A catalogues. Objects presented are those APM/USNO-A optical objects which are calculated with ≥ 40% confidence to be associated with radio/X-ray detections, or whi…
X-ray spectroscopy on Abell 478 with XMM-Newton
Kaastra, J. S.; de Plaa, J.; Pointecouteau, E. +3 more
We report the results from a spatially resolved spectroscopy study with XMM-Newton on the relaxed cluster of galaxies
Hα variability of the recurrent nova T Coronae Borealis
Marziani, P.; Zamanov, R.; Stanishev, V. +1 more
We analyze Hα observations of the recurrent nova
Identification of emission lines in the low-ionization strontium filament near Eta Carinae
Smith, N.; Johansson, S.; Hartman, H. +2 more
We have obtained deep spectra from 1640 to 10 100 Å with the Space Telescope Imaging Spectrograph (STIS) of the strontium filament, a largely neutral emission nebulosity lying close to the very luminous star Eta Carinae and showing an uncommon spectrum. Over 600 emission lines, both permitted and forbidden, have been identified. The majority origi…