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Spectroscopic behaviour of the unusual Ae star HD 190073
Pogodin, M. A.; Franco, G. A. P.; Lopes, D. F.
The results of high-resolution spectroscopy of the peculiar Ae star HD 190073 obtained within the framework of a cooperative observing programme in 1994-2002 are presented. The temporal behaviour of the Hα, Hβ, Hγ, Hδ, He i λ 5876 Å, Na i D and other circumstellar line profiles are investigated in detail. Special attention has been paid to the ana…
2D Feature Recognition And 3d Reconstruction In Solar Euv Images
Aschwanden, Markus J.
EUV images show the solar corona in a typical temperature range of T >rsim 1 MK, which encompasses the most common coronal structures: loops, filaments, and other magnetic structures in active regions, the quiet Sun, and coronal holes. Quantitative analysis increasingly demands automated 2D feature recognition and 3D reconstruction, in order to…
Correlation patterns between 11 diffuse interstellar bands and ultraviolet extinction
Krełowski, J.; Megier, A.; Weselak, T.
We relate the equivalent widths of 11 diffuse interstellar bands, measured in the spectra of 49 stars, to different colour excesses in the ultraviolet. We find that most of the observed bands correlate positively with the extinction in the neighbourhood of the 2175-Åbump. Correlation with colour excesses in other parts of the extinction curve is m…
XMM-Newton data processing for faint diffuse emission. Proton flares, exposure maps and report on EPIC MOS1 bright CCDs contamination
Kerp, J.; Pradas, J.
We present a study of the in-flight performance of the XMM-Newton EPIC MOS and pn detectors, with focus on the influence of proton flares and vignetting on the data. The very wide range in the conditions of our sample of observations, in terms of exposure length and background intensities, allows the detection of a wide range in the spectra of the…
Outflowing material in the compact steep-spectrum source quasar 3C 48: evidence of jet-cloud interaction?
Saikia, D. J.; Srianand, R.; Gupta, Neeraj
We report on the detection of a zabs= 0.3654 associated absorption-line system in the ultraviolet spectrum of the compact steep-spectrum source (CSS) quasar 3C 48. The absorbing material is blueshifted with respect to the quasar emission-line redshift, zem= 0.3700, suggesting an outflow velocity of ~1000 km s-1. We…
The Discovery of Oxygen Kα X-Ray Emission from the Rings of Saturn
Bhardwaj, Anil; Gladstone, G. Randall; Cravens, Thomas E. +3 more
Using the Advanced CCD Imaging Spectrometer (ACIS), the Chandra X-Ray Observatory observed the Saturnian system for one rotation of the planet (~37 ks) on 2004 January 20 and again on January 26-27. In this Letter we report the detection of X-ray emission from the rings of Saturn. The X-ray spectrum from the rings is dominated by emission in a nar…
The Nature of Blue Cores in Spheroids: A Possible Connection with Active Galactic Nuclei and Star Formation
Illingworth, Garth D.; Frye, Brenda; Infante, Leopoldo +9 more
We investigate the physical nature of blue cores in early-type galaxies through the first multiwavelength analysis of a serendipitously discovered field blue-nucleated spheroid in the background of the deep Hubble Space Telescope ACS/WFC griz multicolor observations of the cluster A1689. The resolved g-r, r-i, and i-z color maps reveal a prominent…
Properties of FIRBACK-ELAIS 175-µm sources in the ELAIS N2 region
Dole, H.; Lagache, G.; Puget, J. -L. +15 more
We report on a search for the optical counterparts of 175-µm selected sources from the Far-Infrared Background (FIRBACK) survey in the European Large Area ISO Survey (ELAIS) N2 field. Applying a likelihood ratio technique to optical catalogues from the Isaac Newton Telescope - Wide Field Survey (INT-WFS), we found optical identifications for…
Bifurcated current sheet: model and Cluster observations
Sauvaud, J. -A.; Balogh, A.; Génot, V. +3 more
Cluster observations have recently confirmed previous ISEE and Geotail observations showing that the magnetotail current sheet can present a bifurcated structure with two off-centre current peaks. We show in this paper that such a structure can be described by a kinetic tangential equilibrium which is an exact solution of the Vlasov-Maxwell equati…
Discovery of absorption features of the accretion disc corona and systematic acceleration of the X-ray burst rate in XB1323-619
Church, M. J.; Reed, D.; Dotani, T. +2 more
We present results from analysis of the observation of the dipping, quasi-periodic bursting low mass X-ray binary XB1323-619 made with XMM-Newton in 2003 January. In spectral analysis of the non-dip, non-burst EPIC PN spectrum, a number of absorption lines were discovered, notably at 6.70 and 6.98 keV, which we identify with scattering by high ion…