Search Publications
Dust emission in early-type galaxies: The mid-infrared view
Madden, S. C.; Galliano, F.; Sauvage, M. +2 more
We present mid-infrared (MIR) maps for a sample of 18 early-type galaxies observed at 4.5, 6.7 and 15 µ m with the ISOCAM instrument on board the ISO satellite with a 6'' spatial resolution. We model the Spectral Energy Distribution (SED) of these galaxies using the stellar evolutionary synthesis model PÉGASE and we derive the MIR excess ove…
3D magnetic configuration of the Hα filament and X-ray sigmoid in NOAA AR 8151
Amari, T.; Régnier, S.
We investigate the structure and relationship of an Hα filament and an X-ray sigmoid observed in active region NOAA 8151. We first examine the presence of such structures in the reconstructed 3D coronal magnetic field obtained from the non-constant-α force-free field hypothesis using a photospheric vector magnetogram (IVM, Mees Solar Observatory).…
The diameter and evolutionary state of Procyon A. Multi-technique modeling using asteroseismic and interferometric constraints
Bordé, P.; Provost, J.; Berthomieu, G. +3 more
We report the angular diameter measurement obtained with the VINCI/VLTI instrument on the nearby star Procyon A (α CMi A, F5IV-V), at a relative precision of ± 0.9%. We obtain a uniform disk angular diameter in the K band of θUD = 5.376±0.047 mas and a limb darkened value of θLD = 5.448±0.053 mas. Together with the HIPPARCOS …
Coronal plasma flows and magnetic fields in solar active regions. Combined observations from SOHO and NSO/Kitt Peak
Marsch, E.; Xia, L. D.; Wiegelmann, T.
During the early days of the SOHO mission, SUMER observed a few active regions (ARs) connected with sunspots on the Sun and took their images and spectra in various EUV emission lines. In addition to these spectroscopic data magnetograms of the photospheric footpoint regions of the AR loops were available from the MDI on SOHO and the National Sola…
X-ray reprocessing in Seyfert galaxies: Simultaneous XMM-Newton/BeppoSAX observations
Perola, G. C.; Bianchi, S.; Guainazzi, M. +2 more
We selected a sample of eight bright unobscured (at least at the iron line energy) Seyfert galaxies observed simultaneously by XMM-Newton and BeppoSAX, taking advantage of the complementary characteristics of the two missions. The main results of our analysis can be summarized as follows: narrow neutral iron lines are confirmed to be an ubiquitous…
First determination of the dynamical mass of a binary L dwarf
Duchêne, G.; Martín, E. L.; Bouy, H. +11 more
We present here the results of astrometric, photometric and spectroscopic observations leading to the determination of the orbit and dynamical masses of the binary L dwarf 2MASSW J0746425+2000321. High angular resolution observations spread over almost 4 years and obtained with the Hubble Space Telescope (HST), the ESO Very Large Telescope (VLT), …
A possible age-metallicity relation in the Galactic thick disk?
Feltzing, S.; Bensby, T.; Lundström, I.
A sample of 229 nearby thick disk stars has been used to investigate the existence of an age-metallicity relation (AMR) in the Galactic thick disk. The results indicate that that there is indeed an age-metallicity relation present in the thick disk. By dividing the stellar sample into sub-groups, separated by 0.1 dex in metallicity, we show that t…
Coronal transients and metric type II radio bursts. I. Effects of geometry
Raymond, J. C.; Mancuso, S.
In this paper we investigate the relationship between type II and coronal transient activity in terms of emission originating from the top or the flanks of a bow/piston shock surface, extending just above the coronal mass ejection (CME) leading edge surface. For this purpose, we used ground-based metric type II radio burst observations of twenty-n…
Mapping the inner regions of MCG-6-30-15 with XMM-Newton
Cappi, M.; Ponti, G.; Dadina, M. +1 more
Timing analysis of a ∼95 ks long XMM-Newton observation of the Seyfert 1 galaxy MCG-6-30-15 is presented. Model-independent tools have been used with the intent of resolving the different components that produce the observed flux and spectral variations down to timescales as short as ∼300 s. We find that the fractional variability is possibly due …
XMM-Newton observation of Kepler's supernova remnant
Ballet, J.; Decourchelle, A.; Hughes, J. P. +4 more
We present the first results coming from the observation of Kepler's supernova remnant obtained with the EPIC instruments on board the XMM-Newton satellite. We focus on the images and radial profiles of the emission lines (Si K, Fe L, Fe K) and of the high energy continuum. Chiefly, the Fe L and Si K emission-line images are generally consistent w…