Search Publications
Spatial and temporal fluctuations in sunspots derived from MDI data
Solanki, S. K.; Rüedi, I.
The penumbra radiates an energy flux that is 0.75-0.8 times the photospheric value. One mechanism proposed to bring this flux to the surface is interchange convection according to which hot flux tubes rise to the surface, lie horizontally there while they cool and finally sink down again. We search for possible signatures of such a process using t…
Response of the groove in heliospheric Lyman-alpha glow to latitude-dependent ionization rate
Bzowski, M.
I study the model response of the latitudinal profile of the heliospheric Lyman-alpha glow to various profiles of the ionization rate. The two profiles are characterized by their range separately in the north and south hemisphere, and by the contrast between the equator values and north and south pole values. These parameters define a mesh of the …
RX J0042.3+4115: A stellar mass black hole binary identified in M 31
Kolb, U.; Borozdin, K. N.; Osborne, J. P. +1 more
Four XMM-Newton X-ray observations of the central region of the
Heating the magnetically open ambient background corona of the Sun by Alfvén waves
Peter, H.; Vocks, C.
Observations of UVCS/SOHO of very high emission line widths in the outer corona suggest that the open field regions there are heated by ion-cyclotron resonance absorption of Alfvén waves resulting in the ions being much hotter than the electrons. In the lower corona it is usually assumed that the effective Coulomb-interactions ensure equal tempera…
Far infrared observations of pre-protostellar sources in Lynds 183
Prusti, T.; Juvela, M.; Lemke, D. +3 more
Using ISOPHOT maps at 100 and 200 mu m and raster scans at 100, 120, 150 and 200 mu m we have detected four unresolved far-infrared sources in the high latitude molecular cloud L 183. Two of the sources are identified with 1.3 mm continuum sources found by Ward-Thompson et al. (\cite{wthompson94}, \cite{wthompson00}) and are located near the tempe…
13C isotope effects on infrared bands of quenched carbonaceous composite (QCC)
Onaka, T.; Yamamura, I.; Wada, S. +2 more
We investigate carbon isotope effects on the infrared bands of a laboratory analogue of carbonaceous dust, the quenched carbonaceous composite (QCC), synthesized from a plasma gas of methane with various 12C/13C ratios. Peak shifts to longer wavelengths due to the substitution of 12C by 13C are clearly o…
Mid-infrared observations of GRS 1915+105 during plateau and flaring states
Fuchs, Y.; Mirabel, I. F.; Claret, A.
We present mid-infrared (4-18 mu m) observations of the microquasar GRS 1915+105 obtained with ISOCAM, the camera on board the Infrared Space Observatory (ISO), in 1996 April and 1997 October. The first observation probably occurred during a flaring event with oscillating synchrotron emission. The 1997 observation occurred a few days before a majo…
A comparison between model calculations and observations of sunspot oscillations
Cally, P. S.; Rüedi, I.
We investigate the signal which is expected to be produced by magnetic field oscillations in sunspots umbrae due to the combination of the oscillation model, radiative transfer and observing procedure. For this purpose we investigate the signal expected to be produced by theoretical models of sunspot oscillations and compare them with the signal s…
The distance to the LMC cluster NGC 1866; clues from the cluster Cepheid population
Salaris, M.; Groenewegen, M. A. T.
Recent investigations aimed at estimating the distance to the young LMC cluster NGC 1866 have made use of Red Clump stars in the surrounding LMC field, together with empirical and theoretical Main-Sequence fitting methods, and have found significantly different distances for the field and the cluster, the latter being closer by in distance modulus…
ISO-SWS calibration and the accurate modelling of cool-star atmospheres. III. A0 to G2 stars
Gustafsson, B.; Decin, L.; Vandenbussche, B. +4 more
Vega, Sirius, beta Leo, alpha Car and alpha Cen A belong to a sample of twenty stellar sources used for the calibration of the detectors of the Short-Wavelength Spectrometer on board the Infrared Space Observatory (ISO-SWS). While general problems with the calibration and with the theoretical modelling of these stars are reported in {Decin} et al.…