Search Publications
Correlated Infrared and X-ray variability of the transient Anomalous X-ray Pulsar XTE J1810-197
Covino, S.; Campana, S.; Tiengo, A. +10 more
We report on observations aimed at searching for flux variations from the proposed IR counterpart of the Anomalous X-ray Pulsar (AXP) XTE J1810-197. These data, obtained in March 2004 with the adaptive optics camera NAOS-CONICA at the ESO VLT, show that the candidate proposed by Israel et al. (\cite{Israel04}, ApJ, 603, L97) was fainter by Δ H=0.7…
Jet emission in NGC 1052 at radio, optical, and X-ray frequencies
Pogge, R. W.; Kadler, M.; Kerp, J. +3 more
We present a combined radio, optical, and X-ray study of the nearby LINER galaxy NGC 1052. Data from a short (2.3 ks) CHANDRA observation of NGC 1052 reveal the presence of various jet-related X-ray emitting regions, a bright compact core and unresolved knots in the jet structure as well as an extended emitting region inside the galaxy well aligne…
Line profile characteristics of solar explosive event bursts
Solanki, S. K.; Innes, D. E.; Ning, Z.
The spatial structure and temporal evolution of explosive events are explored using spectral observations of the Si IV 1393 Å line obtained with the Solar Ultraviolet Measurements of Emitted Radiation spectrograph (SUMER). Three areas of quiet Sun near disk center, 8 arcsec×120 arcsec each, were rastered with a cadence of less than 1 min for a per…
Menzel 3: Dissecting the ant
Balick, B.; Corradi, R. L. M.; Santander-García, M. +1 more
The structure and kinematics of the bipolar nebula Mz 3 have been investigated by means of HST, CTIO and ESO images and spectra. At least four distinct outflows have been identified which, from the inside to the outside, are the following: a pair of bright bipolar lobes, two opposite highly collimated column-shaped outflows, a conical system of ra…
An XMM-Newton observation of the dynamically active binary cluster A1750
Pratt, G. W.; Bourdin, H.; Sauvageot, J. -L. +1 more
We present results from the XMM-Newton observation of the binary cluster A1750 at z = 0.086. We have performed a detailed study of the surface brightness, temperature and entropy distribution and confirm that the two main clusters of the system (A1750 N and A1750 C) have just started to interact. From the temperature distribution, we calculate tha…
Optical observations of Comet 67P/Churyumov-Gerasimenko
Rauer, H.; Weiler, M.; Helbert, J.
From longslit spectra obtained during the 1996 perihelion passage of Comet 67P/Churyumov-Gerasimenko, a CN production rate of (1.35 ± 0.35) × 1025 molecules s-1 was determined and an upper limit for the C3 production rate of 1 × 1025 molecules s-1 was derived. The dust color and dust activity …
FUSE observations of the H I interstellar gas of I Zw 18
Kunth, D.; Lebouteiller, V.; Lecavelier des Etangs, A. +5 more
We present the analysis of FUSE observations of the metal-deficient dwarf galaxy I Zw 18 . We measured column densities of H I, N I, O I, Ar I, Si II, and Fe II. The O I/H I ratio (\log(O I/H I)=-4.7+0.8-0.6) is consistent with the O/H ratio observed in the H II regions (all uncertainties are 2-σ). If the oxygen is depleted i…
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…