Search Publications
Ubiquitous quiet-Sun jets
Martínez Pillet, V.; Quintero Noda, C.; Del Toro Iniesta, J. C.
Context. IMaX/Sunrise has recently reported the temporal evolution of highly dynamic and strongly Doppler shifted Stokes V signals in the quiet Sun.
Aims: We attempt to identify the same quiet-Sun jets in the Hinode spectropolarimeter (SP) data set.
Methods: We generate combinations of linear polarization magnetograms with blue- and reds…
A method for filling gaps in solar irradiance and solar proxy data
Dudok de Wit, T.
Context. Data gaps are ubiquitous in spectral irradiance data, and yet, little effort has been put into finding robust methods for filling them.
Aims: We introduce a data-adaptive and nonparametric method that allows us to fill data gaps in multi-wavelength or in multichannel records.
Methods: This method, which is based on the iterative…
A relationship between the solar rotation and activity in the period 1998-2006 analysed by tracing small bright coronal structures in SOHO-EIT images
Hanslmeier, A.; Wöhl, H.; Brajša, R. +4 more
Aims: The study aims to find a relationship between the rotation of the small bright coronal structures (SBCS) described by the solar rotation parameters and indices of solar activity on monthly and yearly temporal scales.
Methods: We analyse precise measurements of the solar differential rotation determined by tracing SBCS in SOHO-EIT i…
A comparison of preprocessing methods for solar force-free magnetic field extrapolation
Wiegelmann, T.; Valori, G.; Fuhrmann, M. +1 more
Context. Extrapolations of solar photospheric vector magnetograms into three-dimensional magnetic fields in the chromosphere and corona are usually done under the assumption that the fields are force-free. This condition is violated in the photosphere itself and a thin layer in the lower atmosphere above. The field calculations can be improved by …
The last revolution of new comets: the role of stars and their detectability
Rickman, H.; Valsecchi, G. B.; Fouchard, M. +1 more
Context. This work is a follow-up of a previous study, where we simulated the dynamical evolution of the Oort Cloud over 5 Gyr with special attention to the injection of comets into observable orbits.
Aims: We wish to clarify how comet injection operates with two types of perturbers: Galactic tides and passing stars. We illustrate why attempt…
HD 5388 b is a 69 MJup companion instead of a planet
Queloz, D.; Sahlmann, J.; Ségransan, D. +1 more
We examined six exoplanet host stars with non-standard Hipparcos astrometric solution, which may be indicative of unrecognised orbital motion. Using Hipparcos intermediate astrometric data, we detected the astrometric orbit of HD 5388 at a significance level of 99.4% (2.7 σ). HD 5388 is a metal-deficient star and hosts a planet candidate with a mi…
The fundamental parameters of the roAp star γ Equulei
Chesneau, O.; Goldfinger, P. J.; Sturmann, J. +18 more
Context. A precise comparison of the predicted and observed locations of stars in the H-R diagram is needed when testing stellar interior theoretical models. For doing this, one must rely on accurate, observed stellar fundamental parameters (mass, radius, luminosity, and abundances).
Aims: We determine the angular diameter of the rapidly osci…
The (sub-)millimeter SED of protoplanetary disks in the outskirts of the Orion nebula cluster
Robberto, M.; Testi, L.; Natta, A. +5 more
We present the sub-mm/mm SED for a sample of eight young circumstellar disks in the outer regions of the Orion nebula cluster (ONC). New observations were carried out at 2.9 mm with the CARMA array and for one disk, 216-0939, at 3.3 and 6.8 mm with ATCA. By combining these new millimeter data with literature measurements at sub-millimeter waveleng…
Discovery of the X-ray selected galaxy cluster XMMU J0338.8+0021 at z = 1.49. Indications of a young system with a brightest galaxy in formation
Böhringer, H.; Rosati, P.; Šuhada, R. +11 more
We report the discovery of a galaxy cluster at z = 1.490 originally selected as an extended X-ray source in the XMM-Newton Distant Cluster Project. Further observations carried out with the VLT-FORS2 spectrograph allowed the spectroscopic confirmation of seven secure cluster members, providing a median system redshift of z = 1.490 ± 0.009. The col…
First hyperfine resolved far-infrared OH spectrum from a star-forming region
van Dishoeck, E. F.; Bergin, E. A.; Goicoechea, J. R. +9 more
OH is an important molecule in the H2O chemistry and the cooling budget of star-forming regions. The goal of the Herschel key program "Water In Star-forming regions with Herschel" (WISH) is to study H2O and related species during protostellar evolution. Our aim in this Letter is to assess the origin of the OH emission from st…