Search Publications
Prominence Seismology: Wavelet Analysis of Filament Oscillations
Isobe, Hiroaki; Tripathi, Durgesh; Pintér, Balázs +1 more
The temporal and spatial behavior of a large-amplitude filament oscillation is investigated using wavelet analysis. The extreme-ultraviolet (EUV) images of the phenomenon, which occurred on 2002 October 15, were taken from the EUV Imaging Telescope on board the Solar and Heliospheric Observatory (SOHO). The wavelet spectra, extracted from the inte…
Segmentation of Loops from Coronal EUV Images
Feng, L.; Inhester, B.; Wiegelmann, T.
We present a procedure to extract bright loop features from solar EUV images. In terms of image intensities, these features are elongated ridge-like intensity maxima. To discriminate the maxima, we need information about the spatial derivatives of the image intensity. Commonly, the derivative estimates are strongly affected by image noise. We ther…
Near-Infrared Adaptive Optics Imaging of High-Redshift Quasars
Uslenghi, Michela; Scarpa, Riccardo; Treves, Aldo +2 more
The properties of high-redshift quasar host galaxies are studied in order to investigate the connection between galaxy evolution, nuclear activity, and the formation of supermassive black holes. We combine new near-IR observations of three high-redshift quasars (2 < z < 3), obtained at the ESO Very Large Telescope equipped with adaptive opti…
Probing the Relation Between X-Ray-Derived and Weak-Lensing-Derived Masses for Shear-Selected Galaxy Clusters. I. A781
Hughes, John P.; Sehgal, Neelima; Tyson, J. Anthony +4 more
We compare X-ray and weak-lensing masses for four galaxy clusters that comprise the top-ranked shear-selected cluster system in the Deep Lens Survey. The weak-lensing observations of this system, which is associated with A781, are from the Kitt Peak Mayall 4 m telescope, and the X-ray observations are from both Chandra and XMM-Newton. For a faithf…
Radiation effects on space-based stellar photometry: theoretical models and empirical results for CoRoT Space Telescope
Auvergne, M.; Rolland, G.; Pinheiro da Silva, L. +1 more
Convection, Rotation and planetary Transits (CoRoT) is a space mission dedicated to stellar seismology and the search for extrasolar planets. Both scientific programs are based on very high precision photometry and require long, uninterrupted observations. The instrument is based on an afocal telescope and a wide-field camera, consisting of four E…
High-latitude plasma convection during Northward IMF as derived from in-situ magnetospheric Cluster EDI measurements
Haaland, S. E.; Torbert, R. B.; Quinn, J. M. +4 more
In this study, we investigate statistical, systematic variations of the high-latitude convection cell structure during northward IMF. Using 1-min-averages of Cluster/EDI electron drift observations above the Northern and Southern polar cap areas for six and a half years (February 2001 till July 2007), and mapping the spatially distributed measurem…
Dust aerosols above the south polar cap of Mars as seen by OMEGA
Bibring, J. -P.; Gondet, B.; Langevin, Y. +4 more
The time evolution of atmospheric dust at high southern latitudes on Mars has been determined using observations of the south seasonal cap acquired in the near infrared (1-2.65 µm) by OMEGA/Mars Express in 2005. Observations at different solar zenith angles and one EPF sequence demonstrate that the reflectance in the 2.64 µm saturated …
The Subaru/XMM-Newton Deep Survey (SXDS). V. Optically Faint Variable Object Survey
Ouchi, Masami; Wang, Lifan; Ueda, Yoshihiro +19 more
We present our survey for optically faint variable objects using multiepoch (8-10 epochs over 2-4 years) i'-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg2 in the Subaru/XMM-Newton Deep Field (SXDF). We found 1040 optically variable objects by image subtraction for all the combinations of images at different epochs. T…
Hemispheric distributions of HCl above and below the Venus’ clouds by ground-based 1.7 µm spectroscopy
Imamura, T.; Kasaba, Y.; Sagawa, H. +8 more
The abundance of hydrogen chloride (HCl) in the Venus atmosphere was measured by ground-based IR spectroscopy. The dayside measurements were performed in May 2007 with a resolution of 40,000, and the nightside measurements in October 1999 with a resolution of 1000. The hemispheric distributions of the HCl mixing ratio measured above the Venus' clo…
Extremely massive young clusters in NGC 1365
Pantin, E.; Panuzzo, P.; Alloin, D. +5 more
Context: In a previous work, three bright mid-infrared/radio sources were discovered in the nuclear region of starburst/AGN galaxy NGC 1365.
Aims: The present study aims to confirm that these sources are indeed young and massive “embedded” clusters, and derive their physical parameters, such as extinction, age and mass.
Methods: Using ISAA…