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The first XMM-Newton spectrum of a high redshift quasar - PKS 0537-286
Tiengo, A.; Boller, Th.; O'Brien, P. T. +6 more
We present XMM-Newton observations of the high redshift (z=3.104), radio-loud quasar PKS 0537-286. The EPIC CCD cameras provide the highest signal-to-noise spectrum of a high-z quasar to date. The EPIC observations show that PKS 0537-286 is extremely X-ray luminous (LX =2 1047 erg s-1), with an unusually hard X-ray…
Multi-frequency variations of the Wolf-Rayet system HD193793 (WC7pd+O4-5) III. IUE observations
Kaper, L.; Wamsteker, W.; Stickland, D. J. +4 more
The colliding-wind binary system WR 140 (HD 193793, WC7pd+O4-5, P = 7.94 yr) was monitored in the ultraviolet by IUE from 1979 to 1994 in 35 short-wavelength high-resolution spectra. An absorption-line radial-velocity solution is obtained from the photospheric lines of the O component, by comparison with a single O star. The resulting orbital para…
Multicolor photometry of the Vela pulsar
Caraveo, P. A.; Mignani, R. P.
Multicolor photometry of the Vela pulsar (PSR B0833-45), updated by recent HST/WFPC2 observations obtained in the 555W, 675W and 814W filters, is presented. The available data provide the best characterization so far of the pulsar spectral shape, which is dominated by a flat power law continuum with spectral index alpha = -0.2 +/- 0.2, consistent …
Evolution of the dust mass loss with luminosity along the giant branch of the globular cluster 47 Tucanae
Jorissen, A.; Ramdani, A.
The present paper investigates the properties of the dust mass loss in stars populating the giant branch of the globular cluster 47 Tuc, by combining ISOCAM and DENIS data. Raster maps of 5 fields covering areas ranging from 4x4 to 15x15 arcmin2 at different distances from the center of the cluster have been obtained with ISOCAM at 11.5…
The galactic mass injection from cool stellar winds of the 1 to 2.5 Msun stars in the solar neighbourhood
Schröder, K. -P.; Sedlmayr, E.
We have computed synthetic stellar samples and HR diagrams on the basis of a fine-meshed, consistent grid of evolution tracks for given IMF and SFR(t). In order to model the galactic disk stellar component (single stars only) and to derive its IMF and apparent SFR(t), we selected the synthetic sample which is the best fit to the observed distribut…
A far infrared view of low mass star formation in the Cederblad 110 nebula of Chamaeleon I
Lemke, D.; Lehtinen, K.; Mattila, K. +1 more
The Cederblad 110 reflection nebula contains several young stellar objects previously discovered by IRAS and sub-mm observations. This cluster was revisited with ISO's FIR cameras and mapped with higher spatial resolution. All sources were also mapped for the first time near the maximum of their spectral energy distribution at 200 mu m. In additio…
The structure of the Akn 120 emitting region: The line shapes and long-term Hβ line profile variation
Bon, E.; Stanić, N.; Kubičela, A. +1 more
To investigate the structure of the Akn 120 emitting region we have analysed the spectral line profiles of Halpha, Hbeta, Lyalpha, C III[1909], C IV[1549] and Mg II[2798] lines using a Gaussian-decomposition approach. The decomposed shape of the Akn 120 lines indicates three separated broad line-emitting regions, i…
EUV Sprays: Jet-like eruptive activity on the solar limb
Harrison, R. A.; Bryans, P.; Bingham, R.
Jet-like eruptive events have been detected in the extreme ultraviolet (EUV) observations from the Solar and Heliospheric Observatory (SOHO) spacecraft. Some jet-like events are shown and for one event, that of January 22 2000, we provide a detailed analysis of the EUV observations. The January 22 observation was part of an on-going campaign to ob…
A nanoflare heating model for the quiet solar corona
Benz, A. O.; Mitra-Kraev, U.
The energy input into the lower solar corona by flare evaporation events has been modeled according to the available observations for quiet regions. The question is addressed whether such heating events can provide the observed average level of the coronal emission measure and thus of the observed flux of extreme ultraviolet (EUV) and X-ray emissi…
Far Ultraviolet Spectroscopic Explorer observations of high-velocity gas associated with the Monoceros Loop SNR
Lallement, R.; Welsh, B. Y.; Sallmen, S. +1 more
We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of high-velocity gas (VLSR = +65 km s-1) seen towards the star HD 47240 which lies just behind the Monoceros Loop Supernova Remnant at a distance of ~ 1800 pc. This high-velocity absorption feature is detected in the far ultraviolet lines of O I, Ar I, N I,…