187,264 research outputs found
Ludwig Reiners, In Europa gehen die Lichter aus. Der Untergang des wilhelminischen Reiches
No full textBrunschwig Henri. Ludwig Reiners, In Europa gehen die Lichter aus. Der Untergang des wilhelminischen Reiches. In: Annales. Economies, sociétés, civilisations. 10ᵉ année, N. 3, 1955. p. 459
Cailà Guitart Montserrat, Escudero, Jean-Paul, Historia dels noms de Reiners, les arrels d'un poble del Vallespir. [Histoire des noms de Reiners. Les racines d'un village du Vallespir], 2005
No full textNéel Guy-Jean. Cailà Guitart Montserrat, Escudero, Jean-Paul, Historia dels noms de Reiners, les arrels d'un poble del Vallespir. [Histoire des noms de Reiners. Les racines d'un village du Vallespir], 2005. In: Nouvelle revue d'onomastique, n°47-48, 2007. p. 264
Cailà Guitart Montserrat, Escudero, Jean-Paul, Historia dels noms de Reiners, les arrels d'un poble del Vallespir. [Histoire des noms de Reiners. Les racines d'un village du Vallespir], 2005
No full textNéel Guy-Jean. Cailà Guitart Montserrat, Escudero, Jean-Paul, Historia dels noms de Reiners, les arrels d'un poble del Vallespir. [Histoire des noms de Reiners. Les racines d'un village du Vallespir], 2005. In: Nouvelle revue d'onomastique, n°47-48, 2007. p. 264
Ludwig Reiners, In Europa gehen die Lichter aus. Der Untergang des wilhelminischen Reiches
No full textBrunschwig Henri. Ludwig Reiners, In Europa gehen die Lichter aus. Der Untergang des wilhelminischen Reiches. In: Annales. Economies, sociétés, civilisations. 10ᵉ année, N. 3, 1955. p. 459
Radial velocity observations of the 2015 Mar. 20 eclipse A benchmark Rossiter-McLaughlin curve with zero free parameters
No full textSpectroscopic observations of a solar eclipse can provide unique information for solar
and exoplanet research; the huge amplitude of the Rossiter-McLaughlin (RM) effect during
solar eclipse and the high precision of solar radial velocities (RVs) allow detailed
comparison between observations and RV models, and they provide information about the
solar surface and about spectral line formation that are otherwise difficult to obtain. On
March 20, 2015, we obtained 159 spectra of the Sun as a star with the solar telescope and
the Fourier Transform Spectrograph at the Institut für Astrophysik Göttingen, 76 spectra
were taken during partial solar eclipse. We obtained RVs using I2 as wavelength
reference and determined the RM curve with a peak-to-peak amplitude of almost
1.4 km s-1 at
typical RV precision better than 1 m s-1. We modeled the disk-integrated solar RVs using
well-determined parameterizations of solar surface velocities, limb darkening, and
information about convective blueshift from 3D magnetohydrodynamic simulations. We confirm
that convective blueshift is crucial to understand solar RVs during eclipse. Our best
model reproduced the observations to within a relative precision of 10% with residuals
lower than 30 m s-1. We cross-checked parameterizations of velocity fields
using a Dopplergram from the Solar Dynamics Observatory and conclude that disk-integration
of the Dopplergram does not provide correct information about convective blueshift
necessary for m s-1
RV work. As main limitation for modeling RVs during eclipses, we identified limited
knowledge about convective blueshift and line shape as functions of solar limb angle. We
suspect that our model line profiles are too shallow at limb angles larger than
μ =
0.6, resulting in incorrect weighting of the
velocities across the solar disk. Alternative explanations cannot be excluded, such as
suppression of convection in magnetic areas and undiscovered systematics during eclipse
observations. To make progress, accurate observations of solar line profiles across the
solar disk are suggested. We publish our RVs taken during solar eclipse as a benchmark
curve for codes calculating the RM effect and for models of solar surface velocities and
line profiles
Mathematische Kenntnisse und Kompetenzen von Studienanfängerinnen und -anfängern mathematikaffiner Studiengänge
No full textGasteiger H, Reiners S, Salle A. Mathematische Kenntnisse und Kompetenzen von Studienanfängerinnen und -anfängern mathematikaffiner Studiengänge. In: Bender P, Wassong T, eds. Beiträge zum Mathematikunterricht 2018. Paderborn, Deutschland: GDM; 2018: 1471–1474
CRIRES spectroscopy and empirical line-by-line identification of FeH molecular absorption in an M dwarf
No full textMolecular FeH provides a large number of sharp and isolated absorption lines that can be
used to measure radial velocity, rotation, or magnetic field strength with high accuracy.
Our aim is to provide an FeH atlas for M-type stars in the spectral region from 986 nm to
1077 nm (Wing-Ford band). To identify these lines in CRIRES spectra of the magnetically
inactive, slowly rotating, M5.5 dwarf GJ1002, we calculated model spectra for the selected
spectral region with theoretical FeH line data. In general this line list agrees with the
observed data, but several individual lines differ significantly in position or in line
strength. After identification of as many as possible FeH lines, we corrected the line
data for position and line strength to provide an accurate atlas of FeH absorption lines
for use in high precision spectroscopy of low mass stars. For all lines, we used a Voigt
function to obtain their positions and equivalent widths. Identification with theoretical
lines was done by hand. For confirmation of the identified lines, we used statistical
methods, cross-correlation techniques, and line intensities. Eventually, we were able to
identify FeH lines from the (0,0), (1,0), (1,1), (2,1), (2,2), (3,2), and (4,3)
vibrational bands in the observed spectra and correct the positions of the lines if
necessary. The deviations between theoretical and observed positions follow a normal
distribution approximately around zero. In order to empirically correct the line strength,
we determined Teff, instrumental broadening (rotational
broadening) and a van der Waals enhancement factor for the FeH lines in GJ1002. We also
give the scaling factors for the Einstein A values to correct the line strengths. With the
identified lines, we derived rotational temperatures from the line intensities for GJ1002.
We conclude that FeH lines can be used for a wide variety of applications in astrophysics.
With the identified lines it will be possible for example to characterize magnetically
sensitive or very temperature sensitive lines, which can be used to investigate M-type
stars
The CARMENES search for exoplanets around m dwarfs: rotational variation in activity indicators of Ross 318, YZ CMi, TYC 3529-1437-1, and EV Lac
Get PDFCARMENES is
funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Científicas (CSIC), the European Union through
FEDER/ERF FICTS-2011-02 funds (...)Schöfer, P., Jeffers, S.V., Reiners, A., Zechmeister, M., Fuhrmeister, B., Lafarga, M., Ribas, I., Quirrenbach, A., Amado, P.J., Caballero, J.A., Anglada-Escudé, G., Bauer, F.F., Béjar, V.J.S., Cortés-Contreras, M., Alonso, E.D., Dreizler, S., Guenther, E.W., Herbort, O., Johnson, E.N., Kaminski, A., Kürster, M., Montes, D., Morales, J.C., Pedraz, S., Tal-Or, L
A high resolution spectral atlas of brown dwarfs
No full textWe present a UVES/VLT high resolution atlas of three L
dwarfs and one T dwarf system, spectral classes at which most of the
objects are brown dwarfs. Our atlas covers the optical region from
Hα up to the near infrared at 1 μm. We present spectral
details of ultra-cool atmospheres at very high resolution () and compare the spectra to model calculations. Our
comparison shows that molecular features from VO and CaH, and atomic
features from Cs and Rb are reasonably well fit by current models.
On the other hand, features due to TiO, CrH, and water, and atomic
Na and K reveal large discrepancies between model calculations and
our observations
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