Search Publications
Dynamic features in the solar atmosphere with unusual spectral line enhancements and Doppler-shifts
Doyle, J. G.; Dzifćáková, E.; Madjarska, M. S. +2 more
Context.The solar atmosphere contains a wide variety of transient features, here, we discuss data relating to one such feature.
Aims.To explore via simultaneous spectral and imaging data the nature of high-velocity flow events in the solar transition region.
Methods.High spectral and temporal resolution data from SUMER/SoHO plus high resol…
INTEGRAL detection of hard X-rays from NGC 6334: nonthermal emission from colliding winds or an AGN?
McBreen, B.; Terrier, R.; Rauw, G. +12 more
Aims.We report the detection of hard X-ray emission from the field of the star-forming region NGC 6334 with the International Gamma-Ray Astrophysics Laboratory INTEGRAL .Methods.The JEM-X monitor and ISGRI imager aboard INTEGRAL and Chandra ACIS imager were used to construct 3-80 keV images and spectra of NGC 6334.Results.The 3-10 keV and 10-35 ke…
On the Lyman α and β lines in solar coronal streamers
Li, B.; Labrosse, N.; Li, X.
Aims.We investigate the formation of the H I Lyman α and Lyman β lines in an equatorial coronal streamer. Particular attention is paid to frequency redistribution for the scattering of the incident radiation. The properties of the spectral lines are studied.
Methods.The coronal model is given by a global 2.5D three fluid solar wind model with α…
Optimal filtering of solar images using soft morphological processing techniques
Fletcher, L.; Marshall, S.; Hough, K.
Context: .CCD images obtained by space-based astronomy and solar physics are frequently spoiled by galactic and solar cosmic rays, and particles in the Earth's radiation belt, which produces an overlaid, often saturated, speckle.
Aims: .We describe the development and application of a new image-processing technique for the removal of this nois…
EUV line intensity distribution in the solar atmosphere: differences between a polar coronal hole and its equatorial extension
Raju, K. P.; Bromage, B. J. I.
Intensity histograms of 14 EUV emission lines in a polar coronal hole, its equatorial extension, the "Elephant's Trunk", and the adjacent quiet Sun regions have been obtained from SOHO/CDS observations made in August and September 1996. Differences between the quiet region and coronal hole on the one hand, and the polar hole and the equatorial ext…
Imaging techniques for gamma-ray diffuse emission: application to INTEGRAL/SPI
Roques, J. -P.; Allain, M.
Diffuse imaging in the gamma-ray energy range is a challenging problem, since faint radiation is usually mixed with strong instrumental background components. This situation results in data sets that are not very informative, so they lead to non robust image reconstruction. In this paper, we used a Bayesian approach to produce sky-maps with high r…
From Hubble diagrams to scale factors
Tilquin, A.; Schücker, T.
Context: .
Aims: .We study the image of the transform from scale parameters to Hubble diagrams and present a lower bound on the radius of the universe today a0 and a monotonicity constraint on the Hubble diagram.
Methods: .Our theoretical input is minimal: Einstein's kinematics and maximally symmetric universes.
Results: .Pr…
Non-radial pulsations in the γ Doradus star HD 195068
Mathias, P.; Jankov, S.; Chapellier, E. +2 more
We present high resolution spectroscopic observations of the γ Doradus star
The color signature of the transit of HD 209458: discrepancies between stellar atmospheric models and observations
Tingley, B.; Thurl, C.; Sackett, P.
Exoplanetary transits produce a double-horned color signature that is distinct from both binaries and blends and can thus be used to separate exoplanets from false positives in transit searches. Color photometry with precision sufficient to detect this signal in transits of HD 209458 is available in the literature. Analysis of these observations r…
A multi-wavelength study of the IRAS Deep Survey galaxy sample. I. Optical observations. The redshift distribution
Aussel, H.; de Zotti, G.; Mazzei, P. +2 more
Context: The IRAS Deep Survey (IDS) of the North Ecliptic Pole region remains one of the deepest complete far-infrared-selected galaxy samples available. ISOCAM observations in the LW3 filter (12-18 µm) of 3.2 arcmin × 3.2 arcmin fields centered on the nominal positions of 94 out of the 98 IDS sources yielding 116 ISOCAM detections. The resu…