Search Publications
Variability of a stellar corona on a time scale of days. Evidence for abundance fractionation in an emerging coronal active region
Nordon, R.; Behar, E.; Drake, S. A.
Elemental abundance effects in active coronae have eluded our understanding for almost three decades, since the discovery of the first ionization potential (FIP) effect on the sun. The goal of this paper is to monitor the same coronal structures over a time interval of six days and resolve active regions on a stellar corona through rotational modu…
Evidence of quiet-Sun chromospheric activity related to an emerging small-scale magnetic loop
Gömöry, P.; Puschmann, K. G.; Balthasar, H.
Aims: We investigate the temporal evolution of magnetic flux emergence in the quiet-Sun atmosphere close to disk center.
Methods: We combined high-resolution SoHO/MDI magnetograms with TRACE observations taken in the 1216 Å channel to analyze the temporal evolution of an emerging small-scale magnetic loop and its traces in the chromosphe…
Polar plumes' orientation and the Sun's global magnetic field
Inhester, Bernd; de Patoul, Judith; Cameron, Robert
Aims: We characterize the orientation of polar plumes as a tracer of the large-scale coronal magnetic field configuration. We monitor in particular the north and south magnetic pole locations and the magnetic opening during 2007-2008 and provide some understanding of the variations in these quantities.
Methods: The polar plume orientatio…
Star formation in the luminous YSO IRAS 18345-0641
Ramsay, S.; Currie, M. J.; Davis, C. J. +2 more
Aims: We aim to understand the star formation associated with the luminous young stellar object (YSO) IRAS 18345-0641 and to address the complications arising from unresolved multiplicity in interpreting the observations of massive star-forming regions.
Methods: New infrared imaging data at sub-arcsec spatial resolution are obtained for …
A new look at the long-period eclipsing binary V383 Scorpii
Gromadzki, M.; Strobel, A.; Gałan, C. +9 more
Context. The system V383 Sco was discovered to be an eclipsing binary star at the beginning of the twentieth century. This system has one of the longest orbital periods known (13.5 yr) and was initially classified as a ζAur-type eclipsing variable. It was then forgotten about for decades, with no progress made in understanding it.
Aims: This …
Extended-object reconstruction in adaptive-optics imaging: the multiresolution approach
Baena Gallé, R.; Núñez, J.; Gladysz, S.
Aims: We propose the application of multiresolution transforms, such as wavelets and curvelets, to reconstruct images of extended objects that have been acquired with adaptive-optics (AO) systems. Such multichannel approaches normally make use of probabilistic tools to distinguish significant structures from noise and reconstruction residuals…
High-resolution spectra of the planetary nebula NGC 6803
Hyung, S.; Lee, S. -J.
We present the high-dispersion spectra of the elliptical ring shaped planetary nebula NGC 6803, secured with the Hamilton Echelle Spectrograph attached to the 3-m Shane telescope of Lick Observatory. Numerous lines from neutral to quadruply ionized ions are presented in the wavelength region from 3650 to 9900 Å. We also use the low dispersion UV s…
Polarization of Saturn's moon Iapetus. III. Models of the bright and the dark sides
Muinonen, K.; Tozzi, G. P.; Boehnhardt, H. +4 more
Context. Like many other atmosphereless solar system bodies, Iapetus exhibits a phenomenon of negative polarization at small phase angles, which can be modeled using theoretical approaches that consider interaction of light with a complex medium.
Aims: To retrieve information on the nature of Iapetus' surface material, we carried out theoreti…
Distant galaxy clusters in a deep XMM-Newton field within the CFTHLS D4
Böhringer, H.; Rosati, P.; Takey, A. +15 more
Aims: The XMM-Newton distant cluster project (XDCP) aims at the identification of a well defined sample of X-ray selected clusters of galaxies at redshifts z ≥ 0.8. As part of this project, we analyse the deep XMM-Newton exposure covering one of the CFHTLS deep fields to quantify the cluster content. We validate the optical follow-up strategy…
AKARI view of star formation in NGC 1313
Onaka, T.; Kaneda, H.; Suzuki, T.
Context. In the southwest region of NGC 1313, patchy star-forming regions are found. In the neighborhood, is a giant supershell with a diameter of 3.2 kpc. However, the direct association between star-forming regions and the giant supershell is still unclear.
Aims: We investigate the relation between the surface densities of the gas (Σga…